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  • 1.
    Ahokas, Essi K.
    et al.
    Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
    Hanstock, Helen
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences (HOV).
    Löfberg, Ida
    Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
    Nyman, Mari
    Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
    Wenning, Piia
    Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
    Kyröläinen, Heikki
    Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
    Mikkonen, Ritva
    Ihalainen, Johanna K.
    Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, FINLAND.
    Nocturnal Heart Rate Variability in Women Discordant for Hormonal Contraceptive Use2023In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 55, no 7, p. 1342-1349Article in journal (Refereed)
    Abstract [en]

    Purpose 

    The aim of this study was to investigate within-cycle differences in nocturnal heart rate (HR) and heart rate variability (HRV) in naturally menstruating women (NM) and women using combined hormonal contraceptives (CU) or progestin-only hormonal contraceptives (PU).

    Methods 

    Physically active participants were recruited into three groups: NM (n = 19), CU (n = 11), and PU (n = 12). Participants’ HR and HRV (with Bodyguard 2 HRV monitor), and blood hormones were monitored during one menstrual cycle (MC) (NM-group) or for 4 weeks (CU and PU-groups). Estradiol, progesterone, and luteinizing hormone were analyzed from fasting blood samples collected four times in the NM (M1 = bleeding, M2 = follicular phase, M3 = ovulation, and M4 = luteal phase) and PU groups (M1 = lowest E2; M2 = M1 + 7 days; M3 = M1 + 14 days; M4 = M1 + 21 days) and twice in the CU group (active and inactive pill phases). After every blood sample, nightly HR and HRV were recorded and examined as an average from two nights.

    Results 

    Hormonal concentrations differed (p < 0.05) between MC phases in the NM- and PU-groups, but not (p ≥ 0.116) between the active and inactive phases in the CU-group. In the NM- and PU-groups, some of the HRV values were higher, while in the NM-group, HR was lower during M2 compared to M3 (p < 0.049) and M4 (p < 0.035). In the CU-group, HRV values (p = 0.014-0.038) were higher, and HR was lower (p = 0.038) in the inactive phase compared to the first week of the active phase.

    Conclusions 

    The MC and hormonal cycle phases influence autonomic nervous system balance, which is reflected in measurements of nocturnal HR and HRV. This should be considered when monitoring recovery in physically active individuals.

  • 2.
    Ainegren, Mats
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Quality Management and Mechanical Engineering.
    Linnamo, Vesa
    Lindinger, Stefan
    Effects of Aerodynamic Drag and Drafting on Propulsive Force and Oxygen Consumption in Double Poling Cross-Country Skiing2022In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 54, no 7, p. 1058-1065Article in journal (Refereed)
    Abstract [en]

    Purpose This study aimed to investigate the effects of aerodynamic drag and drafting on propulsive force (FPROP), drag area (CDA), oxygen cost (V˙O2), metabolic rate (Ė), and heart rate (HR) during roller skiing on a treadmill in a wind tunnel using the double poling technique. A secondary aim was to investigate the effects of wind versus no-wind test conditions on the same physiological parameters. Methods Ten subjects of each gender participated in the experiments. One pair of skiers of the same gender roller skied simultaneously in line with the air flow; the distance between the skiers was 2.05 m. Each pair was tested as follows: I) with wind, leading; II) with wind, drafting; and III) without wind. The treadmill inclination was 0° throughout the tests. For the wind conditions, the air velocity was similar to the treadmill belt speed: 3 to 7 m·s-1 for men and 3 to 6 m·s-1 for women. Results Drafting resulted in significantly (P < 0.05) lower FPROP,CDA, V˙O2, and Ė, compared with leading, for both genders at racing speed but not at lower speeds, whereas HR was only affected for the male skiers at racing speed. The test without wind resulted in significantly lower FPROP, V˙O2, and Ė at all tested speeds compared with the tests with wind present, whereas HR was lower only at higher speeds. Conclusions At racing speed, but not at lower speeds, the positive effects of drafting behind a skier during double poling were obvious and resulted in a lower FPROP, CDA, V˙O2, Ė, and HR. Tests without wind present put even lower demands on the skiers' physiology, which was also evident at lower speeds. 

  • 3. Alkner, Björn
    et al.
    Jonsson, Lena
    Karolinska Institutet.
    Atling, Åsa
    Tesch, Per
    Resistance exercise maintains quadriceps muscle strength and size during 90 d bed rest.2003In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 35, no 5, p. 262-Article in journal (Refereed)
  • 4.
    Anderson, Cheryl B
    et al.
    epartment of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
    Hagströmer, Maria
    Unit for Preventive Nutrition, Department of Biosciences at Novum, Karolinska Institutet, Huddinge, Sweden.
    Yngve, Agneta
    Unit for Preventive Nutrition, Department of Biosciences at Novum, Karolinska Institutet, Huddinge, Sweden.
    Validation of the PDPAR as an adolescent diary: effect of accelerometer cut points2005In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 37, no 7, p. 1224-1230Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate the validity of the Previous Day Physical Activity Recall (PDPAR) as a physical activity diary in adolescents using two accelerometer intensity classifications.

    METHODS: One hundred eighth graders (47 boys, 53 girls) used the PDPAR as a daily diary and wore MTI accelerometers for four consecutive days. Measured time spent in moderate (> or = 3 METs) and vigorous (> or = 6 METs) activity was based on two published MTI cut-point limits (that of Freedson et al./Trost et al. and that of Puyau et al.). Spearman rank order correlations and Bland-Altman plots were used to examine agreement between MTI and PDPAR diary estimates of activity.

    RESULTS: MTI estimates of mean minutes per day of total moderate to vigorous physical activity (MVPA) were 65.2 (+/-43.2) using the Freedson et al./Trost et al. cutoffs and 17.5 (+/-18.5) using those of Puyau et al., while students self-reported 105.1 (+/-80.1) min.d(-1). Significant relationships were observed between the diary and MTI for total MVPA using either the Freedson et al./Trost et al. (r = 0.42) or Puyau et al. (r = 0.41) cutoff as well as raw counts (r = 0.44). Plots showed reasonable agreement between the diary and Freedson et al./Trost et al. MTI estimates of MVPA for daily totals of < or = 60 min, but the Puyau et al. estimates were consistently lower. Diaries overestimated activity as time increased when compared to either MTI cut point, especially on vigorous activity.

    CONCLUSIONS: Time estimates of MVPA differed by assessment tool, but diary estimates showed adequate association with the MTI. Diaries reflected intensity-specific activity, corresponding most closely with the Freedson et al./Trost et al. classification of moderate, but substantially overestimated vigorous activity regardless of cut-point method. This is likely due to the measurement characteristics of the PDPAR, which classifies activities in 30-min blocks, as well as the nature of common activities in which high levels of intensity are not sustained.

  • 5.
    Anderson, Cheryl B
    et al.
    epartment of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
    Hagströmer, Maria
    Unit for Preventive Nutrition, Department of Biosciences at Novum, Karolinska Institutet, Huddinge, Sweden.
    Yngve, Agneta
    Unit for Preventive Nutrition, Department of Biosciences at Novum, Karolinska Institutet, Huddinge, Sweden.
    Validation of the PDPAR as an adolescent diary: effect of accelerometer cut points2005In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 37, no 7, p. 1224-1230Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate the validity of the Previous Day Physical Activity Recall (PDPAR) as a physical activity diary in adolescents using two accelerometer intensity classifications.

    METHODS: One hundred eighth graders (47 boys, 53 girls) used the PDPAR as a daily diary and wore MTI accelerometers for four consecutive days. Measured time spent in moderate (> or = 3 METs) and vigorous (> or = 6 METs) activity was based on two published MTI cut-point limits (that of Freedson et al./Trost et al. and that of Puyau et al.). Spearman rank order correlations and Bland-Altman plots were used to examine agreement between MTI and PDPAR diary estimates of activity.

    RESULTS: MTI estimates of mean minutes per day of total moderate to vigorous physical activity (MVPA) were 65.2 (+/-43.2) using the Freedson et al./Trost et al. cutoffs and 17.5 (+/-18.5) using those of Puyau et al., while students self-reported 105.1 (+/-80.1) min.d(-1). Significant relationships were observed between the diary and MTI for total MVPA using either the Freedson et al./Trost et al. (r = 0.42) or Puyau et al. (r = 0.41) cutoff as well as raw counts (r = 0.44). Plots showed reasonable agreement between the diary and Freedson et al./Trost et al. MTI estimates of MVPA for daily totals of < or = 60 min, but the Puyau et al. estimates were consistently lower. Diaries overestimated activity as time increased when compared to either MTI cut point, especially on vigorous activity.

    CONCLUSIONS: Time estimates of MVPA differed by assessment tool, but diary estimates showed adequate association with the MTI. Diaries reflected intensity-specific activity, corresponding most closely with the Freedson et al./Trost et al. classification of moderate, but substantially overestimated vigorous activity regardless of cut-point method. This is likely due to the measurement characteristics of the PDPAR, which classifies activities in 30-min blocks, as well as the nature of common activities in which high levels of intensity are not sustained.

  • 6.
    Andersson, Erik
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Ørtenblad, Niels
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Björklund, Glenn
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Metabolic responses and pacing strategies during successive sprint skiing time trials2016In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 48, no 12, p. 2544-2554Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To examine the metabolic responses and pacing strategies during the performance of successive sprint time trials (STTs) in cross-country skiing. METHODS: Ten well-trained male cross-country skiers performed four self-paced 1300-m STTs on a treadmill, each separated by 45 min of recovery. The simulated STT course was divided into three flat (1°) sections (S1, S3 and S5) involving the double poling sub-technique interspersed with two uphill (7°) sections (S2 and S4) involving the diagonal stride sub-technique. Treadmill velocity and V˙O2 were monitored continuously and gross efficiency was used to estimate the anaerobic energy supply. RESULTS: The individual trial-to-trial variability in STT performance time was 1.3%, where variations in O2 deficit and V˙O2 explained 69% (P < 0.05) and 11% (P > 0.05) of the variation in performance. The first and last STTs were equally fast (228 ± 10 s), and ~ 1.3% faster than the second and the third STTs (P < 0.05). These two fastest STTs were associated with a 14% greater O2 deficit (P < 0.05), while the average V˙O2 was similar during all four STTs (86 ± 3% of V˙O2max). Positive pacing was used throughout all STTs, with significantly less time spent on the first than second course half. In addition, metabolic rates were substantially higher (~_30%) for uphill than for flat skiing, indicating that pacing was regulated to the terrain. CONCLUSIONS: The fastest STTs were characterized primarily by a greater anaerobic energy production, which also explained 69% of the individual variation in performance. Moreover, the skiers employed positive pacing and a variable exercise intensity according to the course profile, yielding an irregular distribution of anaerobic energy production.

  • 7.
    Andersson, Eva
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Swärd, L
    Thorstensson, Alf
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Trunk muscle strength in athletes.1988In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 20, no 6, p. 587-93Article in journal (Refereed)
    Abstract [en]

    Maximal voluntary strength of the trunk muscles was measured in 57 male elite athletes (soccer players, wrestlers, tennis players, and gymnasts), 14 female elite gymnasts, and in a normal group of 87 conscripts. Mean ages in the different groups ranged from 18-22 yr. An isokinetic (constant velocity) technique was used to record maximal torque produced by trunk and hip muscles during flexion, extension, and lateral flexion over the range of motion. The constant angular velocities used were 15 deg.s-1 and 30 deg.s-1, respectively. Isometric strength was measured in a straight body position (0 deg. of flexion). The measurements were made with the subjects in a horizontal position with the pivot point at the hip and at the lumbar (L2-L3) level. All male athlete groups showed higher peak torque values than the normals. The differences were largest in hip extension and trunk flexion. The male gymnasts also showed significantly higher peak values in hip flexion as compared to all other categories. There was no difference in strength per kg body weight between female gymnasts and untrained males, except in trunk extension. The position for peak torque occurred earlier in the movements for the athletes, especially for the gymnasts in extension movements and for the tennis players in flexion movements. In isometric contractions essentially the same strength differences were present as in the slow isokinetic contractions. In lateral flexion wrestlers and tennis players showed significantly higher strength in movements toward the nondominant side. Thus, differences were present between the athletes and the normals, some of which appeared to be sport specific and related to long-term systematic training.(ABSTRACT TRUNCATED AT 250 WORDS)

  • 8.
    Andersson, Helena M.
    et al.
    Örebro University, School of Health and Medical Sciences.
    Raastad, Truls
    Nilsson, Johnny
    Paulsen, Göran
    Garthe, Ina
    Kadi, Fawzi
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Neuromuscular fatigue and recovery in elite female soccer: effects of active recovery2008In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 40, no 2, p. 372-380Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To investigate the time course of recovery from neuromuscular fatigue and some biochemical changes between two female soccer matches separated by an active or passive recovery regime. METHODS: Countermovement jump (CMJ), sprint performance, maximal isokinetic knee flexion and extension, creatine kinase (CK), urea, uric acid, and perceived muscle soreness were measured in 17 elite female soccer players before, immediately after, 5, 21, 45, 51, and 69 h after a first match, and immediately after a second match. Eight players performed active recovery (submaximal cycling at 60% of HRpeak and low-intensity resistance training at < 50% 1RM) 22 and 46 h after the first match. RESULTS: In response to the first match, a significant decrease in sprint performance (-3.0 +/- 0.5%), CMJ (-4.4 +/- 0.8%), peak torque in knee extension (-7.1 +/- 1.9%) and flexion (-9.4 +/- 1.8%), and an increase in CK (+ 152 +/- 28%), urea (15 +/- 2), uric acid (+ 11 +/- 2%), and muscle soreness occurred. Sprint ability was first to return to baseline (5 h) followed by urea and uric acid (21 h), isokinetic knee extension (27 h) and flexion (51 h), CK, and muscle soreness (69 h), whereas CMJ was still reduced at the beginning of the second match. There were no significant differences in the recovery pattern between the active and passive recovery groups. The magnitude of the neuromuscular and biochemical changes after the second match was similar to that observed after the first match. CONCLUSION: The present study reveals differences in the recovery pattern of the various neuromuscular and biochemical parameters in response to a female soccer match. The active recovery had no effects on the recovery pattern of the four neuromuscular and three biochemical parameters.

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    FULLTEXT01
  • 9.
    Andersson, Helena
    et al.
    Örebro University, Sweden.
    Raastad, Truls
    Nilsson, Johnny
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Paulsen, Gøran
    Garthe, Ina
    Kadi, Fawzi
    Neuromuscular fatigue and recovery in elite female soccer: effects of active recovery.2008In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 40, no 2, p. 372-80Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To investigate the time course of recovery from neuromuscular fatigue and some biochemical changes between two female soccer matches separated by an active or passive recovery regime. METHODS: Countermovement jump (CMJ), sprint performance, maximal isokinetic knee flexion and extension, creatine kinase (CK), urea, uric acid, and perceived muscle soreness were measured in 17 elite female soccer players before, immediately after, 5, 21, 45, 51, and 69 h after a first match, and immediately after a second match. Eight players performed active recovery (submaximal cycling at 60% of HRpeak and low-intensity resistance training at < 50% 1RM) 22 and 46 h after the first match. RESULTS: In response to the first match, a significant decrease in sprint performance (-3.0 +/- 0.5%), CMJ (-4.4 +/- 0.8%), peak torque in knee extension (-7.1 +/- 1.9%) and flexion (-9.4 +/- 1.8%), and an increase in CK (+ 152 +/- 28%), urea (15 +/- 2), uric acid (+ 11 +/- 2%), and muscle soreness occurred. Sprint ability was first to return to baseline (5 h) followed by urea and uric acid (21 h), isokinetic knee extension (27 h) and flexion (51 h), CK, and muscle soreness (69 h), whereas CMJ was still reduced at the beginning of the second match. There were no significant differences in the recovery pattern between the active and passive recovery groups. The magnitude of the neuromuscular and biochemical changes after the second match was similar to that observed after the first match. CONCLUSION: The present study reveals differences in the recovery pattern of the various neuromuscular and biochemical parameters in response to a female soccer match. The active recovery had no effects on the recovery pattern of the four neuromuscular and three biochemical parameters.

  • 10.
    Apró, William
    et al.
    Swedish School of Sport and Health Sciences, Stockholm, Sweden.
    Moberg, Marcus
    Swedish School of Sport and Health Sciences, Stockholm, Sweden.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, Stockholm, Sweden.
    Amino Acid-induced S6K1 Activity in Human Skeletal Muscle is Mediated By Increased mTor/Rheb Interaction: 128 June 1, 11: 15 AM - 11: 30 AM2016In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 48, no 5 Suppl 1, p. 17-Article in journal (Refereed)
    Abstract [en]

    Cell culture studies have shown that amino acids activate mTORC1 signaling by increasing the interaction between mTOR and its essential activator Rheb. However, the existence of this mechanism in human skeletal muscle remains to be determined.

    PURPOSE: To determine if increased mTORC1 signaling in response to amino acids in human skeletal muscle is due to an increased interaction between mTOR and Rheb.

    METHODS: Eight well trained men performed resistance exercise on two separate occasions. In connection with the exercise, subjects were supplemented with flavored water (Pla) and essential amino acids (EAA) in a double-blind, randomized cross-over design. Muscle biopsies were taken in the vastus lateralis muscle before, immediately after and 90 and 180 min post exercise. Activity of the mTORC1 pathway was assessed by a radiolabeled in-vitro kinase assay for its immediate downstream target S6K1. Protein-protein interactions were determined by western blot following co-immunoprecipitation of mTOR with Rheb. Co-immunoprecipitation was performed on pooled muscle samples from three of the eight subjects.

    RESULTS: Activity of S6K1 remained unchanged immediately after exercise in both trials. However, at 90 min post exercise, S6K1 activity increased by approximately 2- and 8-fold (p<0.05) from baseline the Pla and EAA trials, respectively. At the 180 min time point, S6K1 activity remained elevated in both trials being approx. 3-fold higher in the Pla trial and 5-fold higher (p<0.05) in the EAA trial. The fold-change in mTOR and Rheb interaction largely resembled the activity pattern of S6K1 in both trials; in the Pla trial the fold-change was 0.9, 1.3 and 1.4 while in the EAA trial the fold-change was 1.6, 2.9 and 1.9 immediately after, 90 min after and 180 min after exercise, respectively.

    CONCLUSIONS: The large increase in S6K1 activity following EAA intake appears to be mediated by an increased interaction between mTOR and its proximal activator Rheb. This is the first time this mechanism has been demonstrated in human skeletal muscle.

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    Apro et al.
  • 11.
    Apró, William
    et al.
    Swedish School of Sport and Health Sciences, Stockholm, Sweden.
    Moberg, Marcus
    Swedish School of Sport and Health Sciences, Stockholm, Sweden.
    Holmberg, Hans-Christer
    Mittuniversitetet, Avdelningen för hälsovetenskap.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, Stockholm, Sweden.
    Amino Acid-induced S6K1 Activity in Human Skeletal Muscle is Mediated By Increased mTor/Rheb Interaction: 128 June 1, 11: 15 AM - 11: 30 AM2016In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 48, no 5 Suppl 1, p. 17-Article in journal (Refereed)
    Abstract [en]

    Cell culture studies have shown that amino acids activate mTORC1 signaling by increasing the interaction between mTOR and its essential activator Rheb. However, the existence of this mechanism in human skeletal muscle remains to be determined.

    PURPOSE: To determine if increased mTORC1 signaling in response to amino acids in human skeletal muscle is due to an increased interaction between mTOR and Rheb.

    METHODS: Eight well trained men performed resistance exercise on two separate occasions. In connection with the exercise, subjects were supplemented with flavored water (Pla) and essential amino acids (EAA) in a double-blind, randomized cross-over design. Muscle biopsies were taken in the vastus lateralis muscle before, immediately after and 90 and 180 min post exercise. Activity of the mTORC1 pathway was assessed by a radiolabeled in-vitro kinase assay for its immediate downstream target S6K1. Protein-protein interactions were determined by western blot following co-immunoprecipitation of mTOR with Rheb. Co-immunoprecipitation was performed on pooled muscle samples from three of the eight subjects.

    RESULTS: Activity of S6K1 remained unchanged immediately after exercise in both trials. However, at 90 min post exercise, S6K1 activity increased by approximately 2- and 8-fold (p<0.05) from baseline the Pla and EAA trials, respectively. At the 180 min time point, S6K1 activity remained elevated in both trials being approx. 3-fold higher in the Pla trial and 5-fold higher (p<0.05) in the EAA trial. The fold-change in mTOR and Rheb interaction largely resembled the activity pattern of S6K1 in both trials; in the Pla trial the fold-change was 0.9, 1.3 and 1.4 while in the EAA trial the fold-change was 1.6, 2.9 and 1.9 immediately after, 90 min after and 180 min after exercise, respectively.

    CONCLUSIONS: The large increase in S6K1 activity following EAA intake appears to be mediated by an increased interaction between mTOR and its proximal activator Rheb. This is the first time this mechanism has been demonstrated in human skeletal muscle.

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    SUMMARY01
  • 12.
    Apró, William
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Wang, Li
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Endurance Exercise Does Not Impair mTOR Signalling After Resistance Exercise: D-58 Thematic Poster - Skeletal Muscle Cell Signaling: JUNE 2, 2011 3:15 PM - 5:15 PM: ROOM: 3042011In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 43, no 5, p. 52-Article in journal (Other academic)
    Abstract [en]

    Resistance exercise is known to stimulate muscle hypertrophy and this effect is mainly mediated by the mammalian target of rapamycin (mTOR) pathway. In contrast, endurance exercise results in a divergent phenotypic response which to a large extent is mediated by adenosine monophosphate-activated protein kinase (AMPK). Research indicates that molecular interference may exist, possibly through an inhibitory effect on mTOR signalling by AMPK, when these two modes of exercise are combined.

    PURPOSE: To investigate the impact of subsequent endurance exercise on resistance exercise induced mTOR signalling.

    METHODS: In a randomized and cross-over fashion, ten male subjects performed either heavy resistance exercise (R) or heavy resistance exercise followed by endurance exercise (RE) on two separate occasions. The R protocol consisted of thirteen sets of leg press exercise with 3 minutes of recovery allowed between each set. In the RE session, resistance exercise was followed by 15 minutes recovery after which 30 min of cycling was initiated at an intensity equal to 70 % of the subjects' maximal oxygen consumption. Muscle biopsies were collected before, 1 and 3 hours after resistance exercise in both trials. Samples were analyzed for several signalling proteins in the mTOR pathway using western blot technique.

    RESULTS: Phosphorylation of mTOR increased approx. twofold at 1 h post resistance exercise and remained elevated at the 3 h time point (p< 0.01) with no difference between the two trials. Phosphorylation of p70S6k, a downstream target of mTOR, was increased about 6-and18-fold at 1 h and 3 h post resistance exercise (p< 0.01). There was no difference in p70S6k phosphorylation at any time point between the two trials. Phosphorylation of the eukaryotic elongation factor eEF2 was decreased 3- to 4-fold at both time points post resistance exercise (p< 0.01) with no difference between trials. Phosphorylation of AMPK was unchanged at the 1 h time point but decreased approximately 30 % from pre-exercise values in both trials at 3 h post resistance exercise (p< 0.01).

    CONCLUSIONS: The signalling response following heavy resistance exercise is not blunted by subsequent endurance exercise. Supported by the Swedish National Centre for Research in Sports.

  • 13.
    Arvidsson, D.
    et al.
    Univ Gothenburg, Sahlgrenska Acad, Dept Clin Nutr, SE-40530 Gothenburg, Sweden.
    Slinde, Frode
    University of Skövde, School of Life Sciences.
    Larsson, S.
    Univ Gothenburg, Sahlgrenska Acad, Dept Internal Med Respirat Med & Allergology, Gothenburg, Sweden.
    Hulthén, L.
    Univ Gothenburg, Sahlgrenska Acad, Dept Clin Nutr, SE-40530 Gothenburg, Sweden.
    Energy cost of physical activities in children: Validation of SenseWear Armband2007In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 39, no 11, p. 2076-2084Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To examine the validity of SenseWear Pro2 Armband in assessing energy cost of physical activities in children, and to contribute with values of energy costs in an overview of physical activities in children. METHODS: Energy cost was assessed by SenseWear Pro2 Armband in 20 healthy children, 11-13 yr, while lying down resting, sitting playing games on mobile phone, stepping up and down on a step board, bicycling on a stationary bike, jumping on a trampoline, playing basketball, and walking/running on a treadmill at the speeds 2, 3, 4, 5, 6, 7, 8, and 10 km x h(-1). During these activities, energy cost was also assessed from VO2 and VCO2 measured by Oxycon Mobile portable metabolic system, which was used as criterion method. RESULTS: The difference in energy cost between SenseWear Pro2 Armband and Oxycon Mobile was -0.7 (0.5) (P < 0.001) for resting, -2.0 (0.9) (P < 0.001) for playing games on mobile phone, -6.6 (2.3) (P < 0.001) for stepping on the step board, -12.0 (3.7) (P < 0.001) for bicycling, -2.7 (11.9) (P = 0.34) for jumping on the trampoline, and -14.8 (6.4) kJ x min(-1) (P < 0.001) for playing basketball. The difference in energy cost between SenseWear Pro2 Armband and Oxycon Mobile for increasing treadmill speed was 1.3 (3.1) (P = 0.048), 0.1 (2.9) (P = 0.82), -1.2 (2.6) (P = 0.049), -1.6 (3.2) (P = 0.044), -3.1 (3.7) (P = 0.0013), -4.9 (3.7) (P < 0.001), -5.3 (3.7) (P < 0.001), and -11.1 (3.5) kJ x min(-1) (P < 0.001). CONCLUSIONS: SenseWear Pro2 Armband underestimated energy cost of most activities in this study, an underestimation that increased with increased physical activity intensity. A table of energy costs (MET values) of physical activities in children measured by indirect calorimetry is presented as an initiation of the creation of a compendium of physical activities in children

  • 14.
    Arvidsson, Daniel
    et al.
    Department of Clinical Nutrition, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
    Slinde, Frode
    University of Skövde, School of Life Sciences. Department of Clinical Nutrition, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
    Larsson, Sven
    Department of Internal Medicine/Respiratory Medicine and Allergology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
    Hulthén, Lena
    Department of Clinical Nutrition, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
    Energy Cost in Children Assessed by Multisensor Activity Monitors2009In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 41, no 3, p. 603-611Article in journal (Refereed)
    Abstract [en]

     Purpose: The SenseWear Pro2 Armband (SWA; BodyMedia, Inc., Pittsburg, PA), the Intelligent Device for Energy Expenditure and Activity (IDEEA; Minisun LLC, Fresno, CA), and the ActiReg (AR; PreMed AS, Oslo, Norway) were compared with indirect calorimetry to determine the ability of these devices to assess energy cost in children during resting and different physical activities. Methods: Fourteen children, 11–13 yr old, wore the SWA, the IDEEA, and the AR during resting, sitting, stationary bicycling, jumping on a trampoline, playing basketball, stair walking, and walking/running along a 50-m track. The Oxycon Mobile portable metabolic system (VIASYS Healthcare, Conshohocken, PA) was used as the criterion method for energy cost. Results: For resting and sitting, the three activity monitors showed comparable results, but none of them accurately assessed energy cost for stationary bicycling, jumping on a trampoline, or playing basketball. The IDEEA was the only activity monitor that accurately assessed energy cost for stair walking. Also, the IDEEA showed a close estimate of energy cost across the walking and the running intensities, whereas the SWA accurately assessed energy cost for slow to normal walking but showed increased underestimation of energy cost with increasing speed. The AR overestimated energy cost during walking and during slow running but did not respond to increasing running speed. Conclusions: To be able to capture children’s physical activity, all three activity monitors need to be further developed. Overall, the IDEEA showed the highest ability to assess energy cost in this study, but SWA may be more feasible for use in children under free-living conditions.

     

  • 15.
    Bakker, Emily
    et al.
    Norwegian Univ Sci & Technol, N-7034 Trondheim, Norway.
    Engan, Harald
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Patrician, Alexander
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Karlsen, Trine
    Norwegian Univ Sci & Technol, N-7034 Trondheim, Norway.
    Wisloff, Ulrik
    Norwegian Univ Sci & Technol, N-7034 Trondheim, Norway.
    Gaustad, Svein Erik
    Norwegian Univ Sci & Technol, N-7034 Trondheim, Norway.
    Effects Of Dietary Nitrate Supplementation On Endothelial Function At High Altitude2014In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 46, no 5, p. 424-424Article in journal (Other academic)
  • 16. Berg, H. E.
    et al.
    Eiken, Ola
    Swedish Defence Research Agency.
    Muscle control in elite alpine skiing1999In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 31, no 7, p. 1065-1067Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The purpose of this study was to determine whether muscle control may be influenced by accelerative forces brought about by the downhill displacement of body mass in combination with the sharp turns during alpine skiing.

    METHODS: Sixteen elite skiers performed either super G (SG), giant slalom (GS), slalom (SL), or freestyle mogul (FM) skiing. Knee and hip joint angles and electromyographic (EMG) activity of the knee extensors were recorded.

    RESULTS: During the course of a turn, the minimum (deepest stance position) knee angle of the outside (main load-bearing) leg ranged from 60 degrees to 100 degrees, where the smallest angle was obtained in the FM event. Among the traditional alpine disciplines, smaller knee angles were obtained in the high-speed events (i.e., knee angle: SG<GS<SL). Knee angular velocity of the outside leg ranged from 15 degrees to 300 degrees x s(-1), with the slower movements in the high-speed disciplines (i.e., knee angular velocity: SG<GS<SL<FM). In all disciplines, EMG activity reached near-maximal levels during the course of a turn. In SG, GS, and SL, but not in FM skiing, a marked predominance of eccentric over concentric muscle actions was observed. The dominance of slow eccentric muscle actions has not been observed in other athletic activities.

    CONCLUSIONS: We believe these results have important implications for the design of specific training models.

  • 17. Berg, H E
    et al.
    Eiken, Ola
    Karolinska Institutet.
    Tesch, P A
    Involvement of eccentric muscle actions in giant slalom racing.1995In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 27, no 12, p. 1666-70Article in journal (Refereed)
    Abstract [en]

    Joint angular movements and muscle activation (EMG), were determined in male elite racers while performing the giant slalom. Movement cycles averaged 3.5 +/- 0.6 s (left plus right turn), and knee angle ranged 66-114 degrees (180 degrees = straight leg). Knee extensor muscle use was dominated (rectified EMG; P < 0.05) by the leg controlling the outside (downhill) ski during the turn. Time spent while decreasing knee angle (eccentric muscle action) of outside leg averaged 1.0 +/- 0.2 s. This phase was longer (P < 0.05) than the average push-off (concentric muscle action) phase of 0.5 +/- 0.1 s. Moreover, EMG activity of the outside leg during eccentric muscle actions exceeded (P < 0.05) that of concentric actions and was similar to that attained during maximum isometric knee extension in laboratory tests. Knee and hip angular movement ranged 20-50 degrees. Average joint velocities equalled 20-40 degrees.s(-1) during the turning phase. Thus, competitive giant slalom skiing is dominated by slow eccentric muscle actions performed at near maximum voluntary force. Because of their greater ability to generate force, eccentric muscle actions may be warranted or even required to resist the G-forces induced during the turn phase.

  • 18. Berg, H.E
    et al.
    Eiken, O
    Tesch, P.A
    Involvment of eccentric muscle actions in gaint slalom racing1995In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 27, no 12, p. 1666-1670Article in journal (Refereed)
  • 19. Bergh, U
    et al.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Åstrand, PO
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Maximal oxygen uptake "classical" versus "contemporary" viewpoints.2000In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 32, no 1, p. 85-8Article in journal (Refereed)
    Abstract [en]

    In two articles Timothy Noakes proposes a new physiological model in which skeletal muscle recruitment is regulated by a central "govenor," specifically to prevent the development of a progressive myocardial ischemia that would precede the development of skeletal muscle anaerobiosis during maximal exercise. In this rebuttal to the Noakes' papers, we argue that Noakes has ignored data supporting the existing hypothesis that under normal conditions cardiac output is limiting maximal aerobic power during dynamic exercise engaging large muscle groups.

  • 20.
    Bergman, Frida
    et al.
    Umeå University.
    Wahlström, Viktoria
    Umeå University.
    Wennberg, Patrik
    Umeå University.
    Boraxbekk, Carl-Johan
    Umeå University.
    Sörlin, Ann
    Umeå University.
    Öhberg, Fredrik
    Umeå University.
    Olsson, Tommy
    Umeå University.
    Increasing Physical Activity In Office Workers - An RCT Of Treadmill Workstations2018In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 50, no 5, p. 47-47Article in journal (Other academic)
    Abstract [en]

    PURPOSE: Our primary hypothesis was that an intervention with treadmill workstations would increase time spent walking. Secondary hypotheses were a decrease in time spent sitting with a concomitant increase in time spent standing and in light intensity physical activity (LPA) leading to positive effects on body measurements and body composition.

    METHODS: The intervention group received a treadmill workstation at their office desk during 13 months. Daily time spent sitting, standing and walking and number of steps was measured with activPAL®. Daily time in LPA and MVPA was measured with Actigraph®. Body weight, BMI and waist circumference were measured according to standardized protocols. Dual X-ray Absorptiometry was used to estimate body composition. Mixed models was used for the statistical analysis, with group, day of week (weekday/ weekend), time point and gender as fixed effects and age as a covariate. p<0.05 was considered significant.

    RESULTS: Eighty participants were included. The intervention group significantly increased their time spent walking at all follow-ups, with a difference at 13 months of 22 minutes (p<0.01) and 1645 steps per day (p<0.05), respectively, versus controls. Concomitantly, they decreased their MVPA with 13 minutes per day (p<0.001) at weekdays at 13 months versus baseline. We also found a decrease in LPA with 19 minutes per day (p<0.05), and of 17 minutes per day for MVPA (p<0.001) at 13 months versus baseline at weekends. The control group increased their time spent sitting with 25 minutes per day (p<0.05) and decreased the time spent standing with 35 minutes per day at weekdays (p<0.001) compared to baseline. There was also a decrease in LPA with 14 minutes per day (p<0.01) and in MVPA with 6 minutes per day (p<0.01) versus baseline during weekdays, with a decrease in sitting time with 36 minutes (p<0.05) at weekends. There were no significant changes in body measurements or body composition.

    CONCLUSION: It is possible to increase daily walking time by introducing treadmill workstations at offices. A decreased MVPA within the intervention group may contribute to lack of effects on body measurements and body composition. It is therefore important that future interventions aim at both reducing sedentary time as well as increasing, or at least remaining, MVPA levels.

  • 21.
    Björklund, Glenn
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Stöggl, Thomas
    Department of Sport Science and Kinesiology, University of Salzburg, Austria.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Biomechanical influenced differences in O2 extraction in diagonal skiing: arm versus leg2010In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 42, no 10, p. 1899-1908Article in journal (Refereed)
    Abstract [en]

    Biomechanically Influenced Differences in O-2 Extraction in Diagonal Skiing: Arm versus Leg. Med. Sci. Sports Exerc., Vol. 42, No. 10, pp. 1899-1908, 2010. Purpose: This study aimed to determine whether the differences in oxygen extraction and lactate concentration in arms and legs during cross-country skiing are related to muscle activation or force production and how these differences are influenced by a reduction in exercise intensity. Methods: Nine well-trained male cross-country skiers (age = 22 +/- 3 yr, (V) over dotO(2max) = 5.3 +/- 0.3 L.min(-1) and 69 +/- 3 mL.kg(-1).min(-1)) performed diagonal skiing on a treadmill for 3 min at 90% followed by 6 min at 70% of (V) over dotO(2max). During the final minute of each workload, arterial, femoral, and subclavian venous blood was collected for determination of blood gases, pH, and lactate. EMG was recorded from six upper-and lower-body muscles, and leg and pole forces were measured. Cardiorespiratory variables were monitored continuously. Results: Oxygen extraction in the legs was higher than that in the arms at both 90% and 70% of (V) over dotO(2max) (92% +/- 3% vs 85% +/- 6%, P < 0.05 and 90% +/- 3% vs 78% +/- 8%, P < 0.001). This reduction with decreased workload was more pronounced in the arms (-9.8% +/- 7.7% vs -3.2% +/- 3.2%, P < 0.01). EMGRMS for the arms was higher, and pole ground contact time was greater than the corresponding values for the legs (both P < 0.01). At both intensities, the blood lactate concentration was higher in the subclavian than that in the femoral vein but was lowered more in the subclavian vein when intensity was reduced (all P < 0.001). Conclusions: The higher muscle activation (percentage of maximal voluntary isometric contraction) in the arms and the longer ground contact time of the poles than the legs contribute to the lower oxygen extraction and elevated blood lactate concentration in the arms in diagonal skiing. The better lactate recovery in the arms than that in the legs is aided by greater reductions in muscle activation and pole force when exercise intensity is reduced.

  • 22.
    Björklund, Glenn
    et al.
    Mittuniversitetet, Institutionen för hälsovetenskap.
    Stöggl, Thomas
    Department of Sport Science and Kinesiology, University of Salzburg, Austria.
    Holmberg, Hans-Christer
    Mittuniversitetet, Institutionen för hälsovetenskap.
    Biomechanical influenced differences in O2 extraction in diagonal skiing: arm versus leg2010In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 42, no 10, p. 1899-1908Article in journal (Refereed)
    Abstract [en]

    Biomechanically Influenced Differences in O-2 Extraction in Diagonal Skiing: Arm versus Leg. Med. Sci. Sports Exerc., Vol. 42, No. 10, pp. 1899-1908, 2010. Purpose: This study aimed to determine whether the differences in oxygen extraction and lactate concentration in arms and legs during cross-country skiing are related to muscle activation or force production and how these differences are influenced by a reduction in exercise intensity. Methods: Nine well-trained male cross-country skiers (age = 22 +/- 3 yr, (V) over dotO(2max) = 5.3 +/- 0.3 L.min(-1) and 69 +/- 3 mL.kg(-1).min(-1)) performed diagonal skiing on a treadmill for 3 min at 90% followed by 6 min at 70% of (V) over dotO(2max). During the final minute of each workload, arterial, femoral, and subclavian venous blood was collected for determination of blood gases, pH, and lactate. EMG was recorded from six upper-and lower-body muscles, and leg and pole forces were measured. Cardiorespiratory variables were monitored continuously. Results: Oxygen extraction in the legs was higher than that in the arms at both 90% and 70% of (V) over dotO(2max) (92% +/- 3% vs 85% +/- 6%, P < 0.05 and 90% +/- 3% vs 78% +/- 8%, P < 0.001). This reduction with decreased workload was more pronounced in the arms (-9.8% +/- 7.7% vs -3.2% +/- 3.2%, P < 0.01). EMGRMS for the arms was higher, and pole ground contact time was greater than the corresponding values for the legs (both P < 0.01). At both intensities, the blood lactate concentration was higher in the subclavian than that in the femoral vein but was lowered more in the subclavian vein when intensity was reduced (all P < 0.001). Conclusions: The higher muscle activation (percentage of maximal voluntary isometric contraction) in the arms and the longer ground contact time of the poles than the legs contribute to the lower oxygen extraction and elevated blood lactate concentration in the arms in diagonal skiing. The better lactate recovery in the arms than that in the legs is aided by greater reductions in muscle activation and pole force when exercise intensity is reduced.

  • 23.
    Boon, Hanneke
    et al.
    Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands & Department of Human Biology, Maastricht University, Maastricht, Netherlands.
    Jonkers, Richard A. M.
    Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
    Koopman, Rene
    Department of Movement Sciences, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
    Blaak, Ellen E.
    Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
    Saris, Wim H. M.
    Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
    Wagenmakers, Anton J. M.
    School of Sport and Exercise Science, University of Birmingham, Birmingham, United Kingdom.
    van Loon, Luc J. C.
    Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands & Department of Movement Sciences, Nutrition and Toxicology Research Institute Maastricht, Maastricht University, Maastricht, Netherlands.
    Substrate Source Use in Older, Trained Males after Decades of Endurance Training2007In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 39, no 12, p. 2160-2170Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The purpose of this study was to compare substrate source use in older, long-term exercising, endurance-trained males with sedentary controls. METHODS: [U-C]palmitate and [6,6-H2]glucose tracers were applied to assess plasma free fatty acid (FFA) and glucose oxidation rates, and to estimate muscle- and/or lipoprotein-derived triacylglycerol (TG) and muscle glycogen use. Subjects were 10 long-term exercising, endurance-trained males and 10 sedentary controls (age 57 +/- 1 and 60 +/- 2 yr, respectively). Muscle biopsy samples were collected before and after exercise to assess muscle fiber type-specific intramyocellular lipid and glycogen content. RESULTS: During exercise, plasma palmitate Ra, Rd, and Rox were significantly greater in the trained subjects compared with the controls (Ra: 0.36 +/- 0.02 and 0.25 +/- 0.02; Rd: 0.36 +/- 0.03 and 0.24 +/- 0.02; Rox: 0.31 +/- 0.02 and 0.20 +/- 0.02 mmol.min, respectively, P < 0.01). This resulted in greater plasma FFA and total fat oxidation rates in the trained versus sedentary subjects (P < 0.001). Muscle- and/or lipoprotein-derived TG use contributed 10 +/- 2 and 11 +/- 3% in the trained and control groups, respectively (NS). No significant net changes in muscle fiber lipid content were observed. CONCLUSIONS: Older, endurance-trained males oxidize more fat during moderate-intensity exercise than do sedentary controls. This greater total fat oxidation rate is attributed to a higher plasma FFA release, uptake, and oxidation rate. In contrast, intramyocellular triacylglycerol does not seem to represent a major substrate source during 1 h of moderate-intensity exercise in older trained or sedentary men. ©2007 The American College of Sports Medicine.

  • 24.
    Branth, Stefan
    et al.
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Food, Nutrition and Dietetics.
    Hambraeus, Leif
    Westerterp, Klaas
    Andersson, Agneta
    Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Social Sciences, Department of Food, Nutrition and Dietetics.
    Edsgren, Ronnie
    Mustelin, Markys
    Nilsson, Roger
    Energy turnover in a sailing crew during offshore racing around the world1996In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 28, no 10, p. 1272-1276Article in journal (Refereed)
    Abstract [en]

    Energy turnover during offshore sailing was studied in 11 male crew members of one team during the first three legs of the 1993-1994 Whitbread Round The World Race. The effect of racing on the energy balance of the crew members was studied by anthropometric measurements and dietary intake as calculated from food inventories before and after each leg. Energy turnover, calculated from dietary intake and release of endogenous energy as a result of changes in body composition, was higher than expected (about 18-20 MJ·d-1). These findings were confirmed using the doubly labeled water technique in six crew members during the third leg, in which mean energy turnover was found to be 19.3 MJ·d-1. Changes in body weight and composition indicated a negative energy balance during all legs.

  • 25.
    Bäcklund, Catharina
    et al.
    Umeå University, Faculty of Social Sciences, Department of Food and Nutrition.
    Sundelin, Gunnevi
    Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Physiotherapy.
    Larsson, Christel
    Umeå University, Faculty of Social Sciences, Department of Food and Nutrition.
    Validity of an armband measuring energy expenditure in overweight and obese children2010In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 42, no 6, p. 1154-1161Article in journal (Refereed)
    Abstract [en]

    Purpose: To examine the ability of the SenseWear Pro2 Armband (SWA) to accurately assess energy expenditure in free-living overweight or obese children during a two-week period, by comparison with energy expenditure measured using the doubly labeled water (DLW) method. A second aim was to examine which software version, Innerview Professional 5.1 or Sensewear Professional 6.0, are the most appropriate for use together with SWA in overweight and obese children.

    Method: A random sample of 22 healthy, overweight or obese children (11 girls and 11 boys) aged 8-11 years was recruited from an ongoing intervention study. Energy expenditure in free-living conditions was simultaneously assessed with the SWA and DLW methods during a 14-day period. All data from the SWA were analyzed using InnerView Professional software versions 5.1 (SWA 5.1) and 6.1 (SWA 6.1).

    Results: An accurate estimation in energy expenditure was obtained when SWA 5.1 was used, showing a non-statistically significant difference corresponding to 17 (1200) kJ[middle dot]d-1 compared with the energy expenditure measured using the DLW method. However, when SWA 6.1 was used a statistically significant (18%) underestimation of energy expenditure was obtained, corresponding to 1962 (1034) kJ[middle dot]d-1 compared with the DLW method.

    Conclusion: The SWA together with software version 5.1, but not 6.1, is a valid method for accurately measuring energy expenditure at group level of free-living overweight and obese children.

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  • 26.
    Carlsson, Jörg
    et al.
    Kalmar County Hospital.
    Danielsson, Tom
    Linnaeus University, Faculty of Social Sciences, Department of Sport Science.
    Bergman, Patrick
    Linnaeus University, Faculty of Social Sciences, Department of Sport Science.
    Two-peaked increase of serum myosin heavy chain-α after Ironman demonstrates heart muscle cell death2017In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 5 Supplement 1, p. 186-, article id 734Article in journal (Other academic)
  • 27.
    Carlsson, Magnus
    et al.
    Dalarna University, School of Education, Health and Social Studies, Sport and Health Science.
    Carlsson, Tomas
    Dalarna University, School of Education, Health and Social Studies, Sport and Health Science.
    Hammarström, Daniel
    Dalarna University, School of Education, Health and Social Studies, Sport and Health Science.
    Granath, Johan
    Westergren, Jens
    Dalarna University, School of Education, Health and Social Studies, Sport and Health Science.
    Malm, Christer
    Tonkonogi, Michail
    Dalarna University, School of Education, Health and Social Studies, Sport and Health Science.
    Validation of off-season physiological tests with ski ranking in elite male junior cross-country skiing2012In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 44, no s2, p. 516-516Article in journal (Other academic)
  • 28. Carlsson, Sofia
    et al.
    Andersson, Tomas
    Lichtenstein, Paul
    Michaëlsson, Karl
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Orthopaedics.
    Ahlbom, Anders
    Genetic effects on physical activity: results from the Swedish Twin Registry2006In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 38, no 8, p. 1396-1401Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The aim of this study was to investigate the genetic effects on leisure-time physical activity using data from the Swedish Twin Registry. METHODS: We investigated 13,362 twin pairs (5334 monozygotic and 8028 dizygotic pairs) aged 14-46 yr. Information on leisure-time physical activity was obtained by questionnaire. Correlations and odds ratios of physical activity were calculated for males, females, and monozygotic and dizygotic twins, respectively. Structural equation modeling was used to estimate the contribution of genetic effects as well as common and nonshared environmental factors on leisure-time physical activity. RESULTS: About one third of the twins reported that they exercised regularly (26% in females and 39% in males). The correlations of physical activity were twice as high in monozygotic compared with dizygotic twins, suggesting the presence of genetic effects. The variation in physical activity due to heritage was 57% (95% confidence interval (CI) = 0.49-0.63) in males and 50% (95% CI = 0.49-0.55) in females. The common environmental influence on physical activity was very small compared with the influence from environmental factors unique to the individual. CONCLUSIONS: Our study establishes heredity as an important component behind individual differences in physical activity in adult men and women. This may be one reason behind difficulties in convincing people to adopt an active lifestyle. Still, this study shows that there is a substantial influence on physical activity from environmental factors unique to the individual.

  • 29.
    Ceci, Ruggero L.
    et al.
    Trafikverket.
    Patten, Christopher
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Dunbar, Christopher
    Health Promotion Intervention On Rural Roads In Sweden: A Case Study Of Cycling Safety2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 5, p. 229-229Article in journal (Refereed)
  • 30.
    Ceci, Ruggero L.
    et al.
    Trafikverket.
    Patten, Christopher J
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Health Promotion Intervention On Rural Roads In Sweden: A Case Study Of Cycling Safety2017In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 49, no 5 S, p. 229-229Article in journal (Other academic)
    Abstract [en]

    In Sweden, as well as in many countries in Scandinavia and in northern Europe, there is a growing trend to allocate the daily exercise routines to cycling and walking in the form of work commuting. This has led to an increase of bikers with light race bikes and garment for race bike training along the roads and streets of major cities. One crucial factor is the safety of the bikers on the public roads with mixed traffic. If the cyclist had control over the distance between themselves and the motor vehicle/object, how much space would they give themselves? To investigate how road safety factors such as proximity to vehicles passing the bikers on a rural roads a study was conducted.

    The experiment was conducted in an indoor athletics arena at Lugnet stadium in Falun where 48 participants were assigned to one of three groups. Group one with a balanced order of the object-proximity variable (n = 24); group two with the object-proximity variable ordered closest first and moving outward from the track (n = 12); and group three with object-proximity variable ordered furthest away first and moving inward towards the track (n = 12). The participants were donned with a bicycle helmet with a GoPro camera, a second camera was attached to the handlebars. Independent variables were object proximity to the bicycle lane (cm) measured from the center of the lane; dependent variables were lateral position in cm to moving objects, cycling speed and heart rate.

    The preliminary results suggest that bicycle lane must be at least 140 cm broad to accommodate a ‘comfortable’ passing distance (for the cyclist). The equivalent passing speeds equates to a car speed of approximately 40 km/h. If the car speeds were higher, the bicycle lane will need to be broader.

  • 31.
    Chapman, Mark
    et al.
    Univ San Diego, San Diego, CA 92110 USA..
    Emanuelsson, Eric
    Karolinska Inst, Stockholm, Sweden..
    Arif, Muhammad
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Systems Biology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Lakhia, Zubair
    Chapman Univ, Orange, CA USA..
    Reitzner, Stefan
    Karolinska Inst, Stockholm, Sweden..
    Mardinoglu, Adil
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Systems Biology.
    Sundberg, Carl Johan
    Karolinska Inst, Stockholm, Sweden..
    Skeletal Muscle Proteomics Comparison Between Long-term Trained And Untrained Men And Women2022In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 54, no 9, p. 392-393Article in journal (Other academic)
  • 32. Cornish, Rahchell S
    et al.
    Bolam, Kate A
    School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia.
    Skinner, Tina L
    Effect of caffeine on exercise capacity and function in prostate cancer survivors.2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 3, p. 468-75Article in journal (Refereed)
    Abstract [en]

    PURPOSE: This study aimed to examine the acute effect of caffeine on exercise capacity, exercise-related fatigue, and functional performance in prostate cancer survivors.

    METHODS: In this randomized, placebo-controlled, double-blind crossover study, 30 prostate cancer survivors (age, 70.3 ± 7.7 yr; body mass, 80.5 ± 13.0 kg; mean ± SD) consumed 6.04 ± 0.16 mg·kg(-1) of anhydrous caffeine or a placebo 1 h before completing a battery of exercise capacity and functional performance tests. Testing sessions were separated by 3-4 wk. Immediate fatigue and perceived exertion were measured directly pre- and postexercise at both testing sessions.

    RESULTS: Caffeine increased exercise capacity by 7.93 s (+3.0%; P = 0.010); however, postexercise fatigue and perception of exertion were comparable with the placebo session (P = 0.632 and P = 0.902, respectively). Increases in isometric grip strength trended toward significance in both dominant (+2.9%; P = 0.053) and nondominant (+2.1%; P = 0.061) hands in the caffeine trial compared with placebo. Caffeine ingestion did not result in improvements in performance for any of the remaining functional measures, including the timed up-and-go test, repeated chair stands, 6-m fast walk, and 6-m backward tandem walk. Systolic blood pressure and HR were significantly increased (P = 0.006 and P = 0.040, respectively) upon completion of the testing battery when compared with placebo.

    CONCLUSIONS: Consumption of caffeine 1 h before exercise induced improvements in exercise capacity and muscular strength in prostate cancer survivors. However, there was no change in exercise-related fatigue when compared with placebo despite reduction in timed performance of the 400-m walk. Caffeine seems to enhance exercise tolerance through improved performance with no subsequent increase in fatigue or perception of exertion and may be an appropriate strategy to promote exercise participation in prostate cancer survivors.

  • 33.
    Cotter, Joshua A.
    et al.
    Univ Calif Irvine, Irvine, CA USA .
    Hoang, Theresa
    Univ Calif Irvine, Irvine, CA USA .
    Yu, Alvin
    Univ Calif Irvine, Irvine, CA USA .
    Tesch, Per
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Caiozzo, Vincent J.
    Univ Calif Irvine, Irvine, CA USA .
    Adams, Gregory R.
    Univ Calif Irvine, Irvine, CA USA .
    Counteracting Decrements in Muscle Function and Aerobic Capacity During Unloading Utilizing a Gravity Independent Device2012In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 44, no Suppl 2, p. 110-110Article in journal (Other academic)
  • 34.
    Craig, Cora L
    et al.
    Canadian Fitness and Lifestyle Research Institute, Ottawa, Canada.
    Marshall, Alison L
    chool of Human Movement Studies, University of Queensland, Brisbane, Australia.
    Sjöström, Michael
    PrevNut at Novum, Karolinska Institutet, Stockholm, Sweden.
    Bauman, Adrian E
    Centre for Physical Activity and Health, School of Public Health and Community Medicine, University of NSW, Sydney, Australia.
    Booth, Michael L
    Centre for Advancement of Adolescent Health, New Childrens Hospital, Westmead, Sydney, Australia.
    Ainsworth, Barbara E
    Department of Epidemiology and Biostatistics, Department of Exercise Science, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
    Pratt, Michael
    Division of Physical Activity and Nutrition, Centers for Disease Control, Atlanta, GA; 8 Department of Psychology, San Diego State University, San Diego, CA, USA.
    Ekelund, Ulf
    PrevNut at Novum, Karolinska Institutet, Stockholm, Sweden.
    Yngve, Agneta
    PrevNut at Novum, Karolinska Institutet, Stockholm, Sweden.
    Sallis, James F
    Department of Psychology, San Diego State University, San Diego, CA, USA.
    Oja, Pekka
    UKK Institute, Tampere, Finland.
    International physical activity questionnaire: 12-country reliability and validity2003In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 35, no 8, p. 1381-1395Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Physical inactivity is a global concern, but diverse physical activity measures in use prevent international comparisons. The International Physical Activity Questionnaire (IPAQ) was developed as an instrument for cross-national monitoring of physical activity and inactivity.

    METHODS: Between 1997 and 1998, an International Consensus Group developed four long and four short forms of the IPAQ instruments (administered by telephone interview or self-administration, with two alternate reference periods, either the "last 7 d" or a "usual week" of recalled physical activity). During 2000, 14 centers from 12 countries collected reliability and/or validity data on at least two of the eight IPAQ instruments. Test-retest repeatability was assessed within the same week. Concurrent (inter-method) validity was assessed at the same administration, and criterion IPAQ validity was assessed against the CSA (now MTI) accelerometer. Spearman's correlation coefficients are reported, based on the total reported physical activity.

    RESULTS: Overall, the IPAQ questionnaires produced repeatable data (Spearman's rho clustered around 0.8), with comparable data from short and long forms. Criterion validity had a median rho of about 0.30, which was comparable to most other self-report validation studies. The "usual week" and "last 7 d" reference periods performed similarly, and the reliability of telephone administration was similar to the self-administered mode.

    CONCLUSIONS: The IPAQ instruments have acceptable measurement properties, at least as good as other established self-reports. Considering the diverse samples in this study, IPAQ has reasonable measurement properties for monitoring population levels of physical activity among 18- to 65-yr-old adults in diverse settings. The short IPAQ form "last 7 d recall" is recommended for national monitoring and the long form for research requiring more detailed assessment.

  • 35.
    Craig, Cora L
    et al.
    Canadian Fitness and Lifestyle Research Institute, Ottawa, Canada.
    Marshall, Alison L
    chool of Human Movement Studies, University of Queensland, Brisbane, Australia.
    Sjöström, Michael
    PrevNut at Novum, Karolinska Institutet, Stockholm, Sweden.
    Bauman, Adrian E
    Centre for Physical Activity and Health, School of Public Health and Community Medicine, University of NSW, Sydney, Australia.
    Booth, Michael L
    Centre for Advancement of Adolescent Health, New Childrens Hospital, Westmead, Sydney, Australia.
    Ainsworth, Barbara E
    Department of Epidemiology and Biostatistics, Department of Exercise Science, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
    Pratt, Michael
    Division of Physical Activity and Nutrition, Centers for Disease Control, Atlanta, GA; 8 Department of Psychology, San Diego State University, San Diego, CA, USA.
    Ekelund, Ulf
    PrevNut at Novum, Karolinska Institutet, Stockholm, Sweden.
    Yngve, Agneta
    PrevNut at Novum, Karolinska Institutet, Stockholm, Sweden.
    Sallis, James F
    Department of Psychology, San Diego State University, San Diego, CA, USA.
    Oja, Pekka
    UKK Institute, Tampere, Finland.
    International physical activity questionnaire: 12-country reliability and validity2003In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 35, no 8, p. 1381-1395Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Physical inactivity is a global concern, but diverse physical activity measures in use prevent international comparisons. The International Physical Activity Questionnaire (IPAQ) was developed as an instrument for cross-national monitoring of physical activity and inactivity.

    METHODS: Between 1997 and 1998, an International Consensus Group developed four long and four short forms of the IPAQ instruments (administered by telephone interview or self-administration, with two alternate reference periods, either the "last 7 d" or a "usual week" of recalled physical activity). During 2000, 14 centers from 12 countries collected reliability and/or validity data on at least two of the eight IPAQ instruments. Test-retest repeatability was assessed within the same week. Concurrent (inter-method) validity was assessed at the same administration, and criterion IPAQ validity was assessed against the CSA (now MTI) accelerometer. Spearman's correlation coefficients are reported, based on the total reported physical activity.

    RESULTS: Overall, the IPAQ questionnaires produced repeatable data (Spearman's rho clustered around 0.8), with comparable data from short and long forms. Criterion validity had a median rho of about 0.30, which was comparable to most other self-report validation studies. The "usual week" and "last 7 d" reference periods performed similarly, and the reliability of telephone administration was similar to the self-administered mode.

    CONCLUSIONS: The IPAQ instruments have acceptable measurement properties, at least as good as other established self-reports. Considering the diverse samples in this study, IPAQ has reasonable measurement properties for monitoring population levels of physical activity among 18- to 65-yr-old adults in diverse settings. The short IPAQ form "last 7 d recall" is recommended for national monitoring and the long form for research requiring more detailed assessment.

  • 36.
    Crenshaw, Albert G.
    et al.
    Centre for Musculoskeletal Research, Umea, Sweden.
    Elcadi, Guilherme
    Centre for Musculoskeletal Research, Umea, Sweden.
    Reproducibility And Gender Comparisons Of Oxygenation, Blood Flow And Oxygen Consumption For The Forearm2010In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 42, no 5, p. 384-385Article in journal (Refereed)
  • 37.
    Crenshaw, Albert G.
    et al.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Elcadi, Guilherme H.
    University of Gävle, Faculty of Health and Occupational Studies, Department of Occupational and Public Health Sciences, CBF. University of Gävle, Centre for Musculoskeletal Research.
    Reproducibility and gender comparisons of oxygenation, blood flow and oxygen consumption for the forearm2010In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 42, no 5, p. 384-385Article in journal (Other academic)
  • 38.
    Crenshaw, Albert G.
    et al.
    University of Gävle, Belastningsskadecentrum.
    Heiden, Marina
    University of Gävle, Belastningsskadecentrum.
    Lyskov, Eugene
    University of Gävle, Belastningsskadecentrum.
    Johansson, Håkan
    University of Gävle, Belastningsskadecentrum.
    Reduced muscular oxygenation during computer mouse use with time pressure and precision demands2004In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 35, no 5, p. S221-S222Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Monitoring oxidative metabolic states may provide information on the mechanism behind computer use related musculoskeletal disorders. PURPOSE: To compare tissue oxygen saturation (Sat-O2) profiles in the forearm extensor carpi radialis (ECR) during computer mouse use with and without time pressure and precision demands. METHODS: Twenty-four healthy, right-handed subjects (12 females, 12 males; age 19-28 years) participated in the study. Subjects performed a 45-min mouse operated computer task on two occasions, separated by 3-5 days. The task consisted of painting squares that were presented on the screen. On one occasion, time pressure and precision demands were imposed by limiting the time available for painting a square and introducing a scoring system based on precision of painting (STRESS). On the other occasion, no such restraints were added (NON-STRESS). The order of the two task versions was randomized. During the task, Sat-O2 in the right ECR muscle was measured by near-infrared spectroscopy – NIRS (Inspectra, Hutchinson Technology). In addition, subjective ratings of tenseness and strain, and painting performance measures were recorded. RESULTS: A repeated measures ANOVA revealed a significant decline in Sat-O2 during the STRESS condition (p < 0.05), but no change for the NON-STRESS condition. A gender difference was apparent as females exhibited an overall lower Sat-O2 than males (p < 0.05); however, no interaction was found. Subjectsメ ratings of tenseness and strain were significantly higher during the STRESS as compared to the NON-STRESS condition (p < 0.001). These data were paralleled by work pace (i.e. squares painted during STRESS = 119; NON-STRESS = 84, p < 0.001). Furthermore, accuracy of painting was greater for the STRESS as compared to the NON-STRESS condition (p < 0.01), i.e., number of times outside the square, STRESS = 2, NON-STRESS = 4. No gender differences in subjective ratings or performance variables were detected. CONCLUSIONS: Our finding of a change in local metabolic states under stressful conditions may shed light on the mechanism behind computer mouse related forearm muscular disorders. Furthermore, that females demonstrate a lower ECR Sat-O2 could give precedence to their higher incidence of disorders than males

  • 39.
    Crenshaw, Albert G.
    et al.
    University of Gävle, Centre for Musculoskeletal Research.
    Komandur, Sashidharan
    Department of Environmental and occupational Health Sciences, University of Washington, Seattle.
    Johnson, Peter W
    Department of Environmental and occupational Health Sciences, University of Washington, Seattle.
    Contractile properties and hemodynamics for a sustained submaximal contraction studied with electrical stimulation and NIRS2009In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 41, no 5, p. 220-221Article in journal (Refereed)
  • 40.
    Cunningham, Gregory
    et al.
    Univ Hosp Geneva, Dept Surg, Div Orthoped & Trauma Surg, Geneva, Switzerland..
    Zanchi, Davide
    Univ Hosp Geneva, Dept Imaging & Med Informat, Geneva, Switzerland..
    Emmert, Kirsten
    Univ Hosp Geneva, Dept Imaging & Med Informat, Geneva, Switzerland.;Ecole Polytech Fed Lausanne, Inst Bioengn, Lausanne, Switzerland..
    Kopel, Rotem
    Univ Hosp Geneva, Dept Imaging & Med Informat, Geneva, Switzerland.;Ecole Polytech Fed Lausanne, Inst Bioengn, Lausanne, Switzerland..
    Van De Ville, Dimitri
    Univ Hosp Geneva, Dept Imaging & Med Informat, Geneva, Switzerland.;Ecole Polytech Fed Lausanne, Inst Bioengn, Lausanne, Switzerland..
    Laedermann, Alexandre
    Univ Hosp Geneva, Dept Surg, Div Orthoped & Trauma Surg, Geneva, Switzerland.;Univ Geneva, Fac Med, CH-1227 Geneva, Switzerland..
    Haller, Sven
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Univ Geneva, Fac Med, CH-1227 Geneva, Switzerland.;Univ Hosp Freiburg, Dept Neuroradiol, Freiburg, Germany.;Ctr Diagnost Radiol Carouge, Affidea, Carouge, Switzerland..
    Hoffmeyer, Pierre
    Univ Hosp Geneva, Dept Surg, Div Orthoped & Trauma Surg, Geneva, Switzerland.;Univ Geneva, Fac Med, CH-1227 Geneva, Switzerland..
    Neural Correlates of Clinical Scores in Patients with Anterior Shoulder Apprehension2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 12, p. 2612-2620Article in journal (Refereed)
    Abstract [en]

    Introduction Anterior shoulder apprehension is a commonly reported complaint in anterior shoulder instability, which may lead to patient morbidity and impede shoulder function. It is the result of a cognitively complex mechanism, which includes anxiety, salience, fear, and anticipation. Purpose The aim of this prospective case-control study was to correlate five clinically established scores using functional magnetic resonance imaging to assess brain activation patterns in patients with apprehension related to anterior shoulder instability. Methods This study includes 28 consecutive male right-handed patients ( mean +/- SEM, 26.8 +/- 1.2 yr) with positive shoulder apprehension test and 10 healthy matched control participants without apprehension or a history of instability. Task- related and functional connectivity functional magnetic resonance imaging activation patterns occurring during apprehension video cue stimulation were correlated with five clinical tests and scores: Visual Analog Scale ( VAS), Rowe score for instability, Simple Shoulder Test, Subjective Shoulder Value ( SSV), and Western Ontario Shoulder Instability ( WOSI). Results Rowe, pain VAS, and WOSI scores correlated with prefrontal cortex, dorsolateral prefrontal cortex, dorsomedial prefrontal cortex, somatosensory area, and parieto-occipital and temporal areas (default mode network). Rowe score additionally correlated with frontal pole, anterior midcingulate cortex, and visual areas. Moreover, SSV correlated with task-related brain activity in the bilateral precentral gyrus, bilateral postcentral gyrus, and bilateral superior parietal lobe. Conclusions Overall, Rowe score provides the strongest link between shoulder apprehension and brain level alterations as it correlates with the highest number of independent components involving areas responsible for both motor and cognitive functions, whereas pain VAS and WOSI occupy an intermediately strong link recruiting less brain networks. Finally, Simple Shoulder Test and SSV have the weakest link at the brain level.

  • 41.
    Danielsen, Jorgen
    et al.
    Norwegian Univ Sci & Technol, Dept Neurosci, Ctr Elite Sports Res, Trondheim, Norway.
    Sandbakk, Oyvind
    Norwegian Univ Sci & Technol, Dept Neurosci, Ctr Elite Sports Res, N-7489 Trondheim, Norway.
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Ettema, Gertjan
    Norwegian Univ Sci & Technol, Dept Neurosci, Ctr Elite Sports Res, Trondheim, Norway.
    Mechanical Energy and Propulsion in Ergometer Double Poling by Cross-country Skiers2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 12, p. 2586-2594Article in journal (Refereed)
    Abstract [en]

    Purpose This study aims to investigate fluctuations in total mechanical energy of the body (E-body) in relation to external ergometer work (W-erg) during the poling and recovery phases of simulated double-poling cross-country skiing. Methods Nine male cross-country skiers (mean SD age, 24 5 yr; mean +/- SD body mass, 81.7 +/- 6.5 kg) performed 4-min submaximal tests at low-intensity, moderate-intensity, and high-intensity levels and a 3-min all-out test on a ski ergometer. Motion capture analysis and load cell recordings were used to measure body kinematics and dynamics. From these, W-erg, E-body (sum of the translational, rotational, and gravitational potential energies of all segments), and their time differentials (power P) were calculated. P(tot)the rate of energy absorption or generation by muscles-tendonswas defined as the sum of P-body and P-erg. ResultsE(body) showed large fluctuations over the movement cycle, decreasing during poling and increasing during the recovery phase. The fluctuation in P-body was almost perfectly out of phase with P-erg. Some muscle-tendon energy absorption was observed at the onset of poling. For the rest of poling and throughout the recovery phase, muscles-tendons generated energy to do W-erg and to increase E-body. Approximately 50% of cycle P-tot occurred during recovery for all intensity levels. Conclusions In double poling, the extensive contribution of the lower extremities and trunk to whole-body muscle-tendon work during recovery facilitates a direct transfer of E-body to W-erg during the poling phase. This observation reveals that double poling involves a unique movement pattern different from most other forms of legged terrestrial locomotion, which are characterized primarily by inverted pendulum or spring-mass types of movement.

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  • 42.
    Danielsen, Jorgen
    et al.
    Norwegian Univ Sci & Technol, Dept Neurosci, Ctr Elite Sports Res, Trondheim, Norway.
    Sandbakk, Oyvind
    Norwegian Univ Sci & Technol, Dept Neurosci, Ctr Elite Sports Res, N-7489 Trondheim, Norway.
    Holmberg, Hans-Christer
    Mittuniversitetet, Avdelningen för hälsovetenskap.
    Ettema, Gertjan
    Norwegian Univ Sci & Technol, Dept Neurosci, Ctr Elite Sports Res, Trondheim, Norway.
    Mechanical Energy and Propulsion in Ergometer Double Poling by Cross-country Skiers2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 12, p. 2586-2594Article in journal (Refereed)
    Abstract [en]

    Purpose This study aims to investigate fluctuations in total mechanical energy of the body (E-body) in relation to external ergometer work (W-erg) during the poling and recovery phases of simulated double-poling cross-country skiing. Methods Nine male cross-country skiers (mean SD age, 24 5 yr; mean +/- SD body mass, 81.7 +/- 6.5 kg) performed 4-min submaximal tests at low-intensity, moderate-intensity, and high-intensity levels and a 3-min all-out test on a ski ergometer. Motion capture analysis and load cell recordings were used to measure body kinematics and dynamics. From these, W-erg, E-body (sum of the translational, rotational, and gravitational potential energies of all segments), and their time differentials (power P) were calculated. P(tot)the rate of energy absorption or generation by muscles-tendonswas defined as the sum of P-body and P-erg. ResultsE(body) showed large fluctuations over the movement cycle, decreasing during poling and increasing during the recovery phase. The fluctuation in P-body was almost perfectly out of phase with P-erg. Some muscle-tendon energy absorption was observed at the onset of poling. For the rest of poling and throughout the recovery phase, muscles-tendons generated energy to do W-erg and to increase E-body. Approximately 50% of cycle P-tot occurred during recovery for all intensity levels. Conclusions In double poling, the extensive contribution of the lower extremities and trunk to whole-body muscle-tendon work during recovery facilitates a direct transfer of E-body to W-erg during the poling phase. This observation reveals that double poling involves a unique movement pattern different from most other forms of legged terrestrial locomotion, which are characterized primarily by inverted pendulum or spring-mass types of movement.

  • 43.
    Danielsson, Tom
    et al.
    Linnaeus University, Faculty of Social Sciences, Department of Sport Science.
    Carlsson, Jörg
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Bergman, Patrick
    Linnaeus University, Faculty of Social Sciences, Department of Sport Science.
    Maximal Oxygen Consumption Predicts Skeletal and Heart Muscle Biomarkers Changes after a Full Distance Ironman2017In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 49, no 5, p. 519-, article id 1905Article in journal (Refereed)
    Abstract [en]

    Strenuous exercise like marathon or triathlon leads to disturbances of several biomarkers, not at least markers of skeletal and heart muscle damage. Different predictors of biomarker changes, e.g. sex, age and training experience have been discussed in the literature with contradictory results. To our best knowledge, maximal oxygen consumption (VO2 max) has not been investigated in this setting.

    PURPOSE:  To evaluate predictors of biomarker changes in an Ironman triathlon.

    METHODS: In 39 non-elite athletes (10 female, 29 male; age 41.1 ± 9.7, range 24-70 years) who had performed a 20 m shuttle run test to predict VO2 max, biomarkers (cardiac troponin T (cTnT; reference < 14 ng/L), creatine kinase (CK; ref. < 1.9 µkat/L), myoglobin (MG; ref. <72 µg/L), and N-terminal prohormone of brain natriuretic peptide (NT-proBNP; ref. < 300 ng/L) were measured by standard laboratory methods 7 days before, directly after, and day 1, and 6 after the race.

    RESULTS: VO2 max was on average 49.9 ± 6.4 O2 ml/kg/minute (range 36.5-63.9). Three biomarkers measured directly after the race were predicted by VO2 max: CK (53 ± 50 µkat/L; R= -0.44; p=0.005), MG (2137 ± 2614 µg/L; R= -0.31; p=0.056) and NT-proBNP (772 ±2614 ng/L; R= -0.35; p=0.027). cTnT (75 ± 89) was not significantly predicted by VO2 max but cTnT leakage was, in contrast to the other biomarkers, higher with higher VO2 max (R= 0.10; p=0.55) and return to normal appeared to be faster with higher VO2 max.

    CONCLUSION: Earlier research into predictors of biomarker changes after strenuous exercise has found contradictory results concerning age, sex and training experience. In the present Kalmar IronWoMan study VO2 max was found to be a good predictor of biomarker changes with higher VO2 max values being correlated to lower values for CK, NT-proBNP and MG.           

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  • 44. Debevec, T.
    et al.
    Pialoux, V.
    Mekjavic, I.B.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Mury, P.
    Millet, G.P.
    Moderate exercise blunts oxidative stress induced by normobaric hypoxic confinement2014In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 46, no 1, p. 33-41Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Both acute hypoxia and physical exercise are known to increase oxidative stress. This randomized prospective trial investigated whether the addition of moderate exercise can alter oxidative stress induced by continuous hypoxic exposure. METHODS: Fourteen male participants were confined to 10-d continuous normobaric hypoxia (FIO2 = 0.139 ± 0.003, PIO2 = 88.2 ± 0.6 mm Hg, ∼4000-m simulated altitude) either with (HCE, n = 8, two training sessions per day at 50% of hypoxic maximal aerobic power) or without exercise (HCS, n = 6). Plasma levels of oxidative stress markers (advanced oxidation protein products [AOPP], nitrotyrosine, and malondialdehyde), antioxidant markers (ferric-reducing antioxidant power, superoxide dismutase, glutathione peroxidase, and catalase), nitric oxide end-products, and erythropoietin were measured before the exposure (Pre), after the first 24 h of exposure (D1), after the exposure (Post) and after the 24-h reoxygenation (Post + 1). In addition, graded exercise test in hypoxia was performed before and after the protocol. RESULTS: Maximal aerobic power increased after the protocol in HCE only (+6.8%, P < 0.05). Compared with baseline, AOPP was higher at Post + 1 (+28%, P < 0.05) and nitrotyrosine at Post (+81%, P < 0.05) in HCS only. Superoxide dismutase (+30%, P < 0.05) and catalase (+53%, P < 0.05) increased at Post in HCE only. Higher levels of ferric-reducing antioxidant power (+41%, P < 0.05) at Post and lower levels of AOPP (-47%, P < 0.01) at Post + 1 were measured in HCE versus HCS. Glutathione peroxidase (+31%, P < 0.01) increased in both groups at Post + 1. Similar erythropoietin kinetics was noted in both groups with an increase at D1 (+143%, P < 0.01), a return to baseline at Post, and a decrease at Post + 1 (-56%, P < 0.05). CONCLUSIONS: These data provide evidence that 2 h of moderate daily exercise training can attenuate the oxidative stress induced by continuous hypoxic exposure.

  • 45.
    Diment, Bethany
    et al.
    Bangor University, UK.
    Fortes, Matthew B
    Bangor University, UK.
    Edwards, Jason P
    Bangor University, UK.
    Hanstock, Helen
    Bangor University, UK.
    Ward, Mark D
    Bangor University, UK.
    Dunstall, Huw M
    Bangor University, UK.
    Friedmann, Peter S
    University of Southampton, UK.
    Walsh, Neil P
    Bangor University, UK.
    Exercise Intensity and Duration Effects on In Vivo Immunity2015In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 47, no 7, p. 1390-1398Article in journal (Refereed)
    Abstract [en]

    Purpose: To examine the effects of intensity and duration of exercise stress on induction of in vivo immunity in humans using experimental contact hypersensitivity (CHS) with the novel antigen diphenylcyclopropenone (DPCP).Methods: Sixty-four healthy males completed either 30 min running at 60% V˙O2peak (30MI), 30 min running at 80% V˙O2peak (30HI), 120 min running at 60% V˙O2peak (120MI), or seated rest (CON). Twenty min later, the subjects received a sensitizing dose of DPCP; and 4 wk later, the strength of immune reactivity was quantified by measuring the cutaneous responses to a low dose-series challenge with DPCP on the upper inner arm. Circulating epinephrine, norepinephrine and cortisol were measured before, after, and 1 h after exercise or CON. Next, to understand better whether the decrease in CHS response on 120MI was due to local inflammatory or T-cell-mediated processes, in a crossover design, 11 healthy males performed 120MI and CON, and cutaneous responses to a dose series of the irritant, croton oil (CO), were assessed on the upper inner arm.Results: Immune induction by DPCP was impaired by 120MI (skinfold thickness -67% vs CON; P < 0.05). However, immune induction was unaffected by 30MI and 30HI despite elevated circulating catecholamines (30HI vs pre: P < 0.01) and greater circulating cortisol post 30HI (vs CON; P < 0.01). There was no effect of 120MI on skin irritant responses to CO.Conclusions: Prolonged moderate-intensity exercise, but not short-lasting high- or short-lasting moderate-intensity exercise, decreases the induction of in vivo immunity. No effect of prolonged moderate-intensity exercise on the skin's response to irritant challenge points toward a suppression of cell-mediated immunity in the observed decrease in CHS. Diphenylcyclopropenone provides an attractive tool to assess the effect of exercise on in vivo immunity.

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  • 46.
    Ekblom, Maria M Nordlund
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Thorstensson, Alf
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Effects of prolonged vibration on H-reflexes, muscle activation, and dynamic strength.2011In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 43, no 10, p. 1933-9Article in journal (Refereed)
    Abstract [en]

     Neural activation is generally lower during maximal voluntary lengthening compared with shortening and isometric muscle actions, but the mechanisms underlying these differences are unclear. In maximal voluntary isometric actions, reduced Ia-afferent input induced by prolonged tendon vibration has been shown to impair neural activation and strength.

    PURPOSE: This study aimed to investigate whether reducing Ia-afferent input influences neural activation in maximal voluntary dynamic muscle actions and, if so, whether it affects shortening and lengthening muscle actions differently.

    METHODS: Eight women participated in three familiarization sessions and two randomly ordered experiments. In one experiment, 30-min vibration at 100 Hz was applied to the Achilles tendon to decrease Ia-afferent input as measured by the H-reflex. In the control experiment, rest substituted the vibration. Root mean square EMG from plantar and dorsiflexor muscles and plantar flexor strength were measured during maximal voluntary plantar flexor shortening and lengthening actions (20°·s(-1)) before and after vibration and rest, respectively. Soleus H-reflexes and M-waves were elicited before each set of strength tests.

    RESULTS: The vibration caused a decrease in H-reflex amplitude by, on the average, 33%, but root mean square EMG and plantar flexor strength remained largely unaffected in both action types.

    CONCLUSIONS: The findings suggest that Ia-afferent input may not substantially contribute to maximal voluntary dynamic muscle strength of the plantar flexor muscles, as tested here, and thus, the results do not support the notion that Ia-afferent excitation would contribute differently to neural activation in maximal voluntary lengthening and shortening muscle actions.

  • 47.
    Ekelund, Ulf
    et al.
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden. Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Sjöström, Michael
    Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Yngve, Agneta
    Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Poortvliet, Eric
    Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Nilsson, Andreas
    Örebro University, School of Health and Medical Sciences, Örebro University, Sweden.
    Fröberg, Karsten
    Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    Wedderkopp, Niels
    Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    Westerterp, Klaas
    Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
    Physical activity assessed by activity monitor and doubly labeled water in children2001In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 33, no 2, p. 275-281Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To validate the Computer Science and Application's (CSA) activity monitor for assessment of the total amount of physical activity during two school-weeks in 9-yr-old children and to develop equations to predict total energy expenditure (TEE) and activity energy expenditure (AEE) from activity counts and anthropometric variables.

    METHODS: A total of 26 children (15 boys and 11 girls, mean age 9.1 +/- 0.3 yr) were monitored for 14 consecutive days. TEE was simultaneously measured by the doubly labeled water method. Averaged activity counts (counts.min(-1)) were compared with data on: 1) TEE, 2) AEE = TEE minus basal metabolic rate (BMR; estimated from predictive equations), and 3) daily physical activity level (PAL = TEE/BMR).

    RESULTS: Physical activity determined by activity counts was significantly related to the data on energy expenditures: TEE (r = 0.39; P < 0.05), AEE (r = 0.54; P < 0.01), and PAL (r = 0.58; P < 0.01). Multiple stepwise regression analysis showed that TEE was significantly influenced by gender, body composition (body weight or fat free mass), and activity counts (R(2) = 0.54--0.60). AEE was significantly influenced by activity counts and gender (R(2) = 0.45). There were no significant differences between activity counts and PAL in discriminating among activity levels with "low" (PAL < 1.56), "moderate" (1.57 < or = PAL > or = 1.81), and "high" (PAL > 1.81) intensity.

    CONCLUSION: Activity counts from the CSA activity monitor seems to be a useful measure of the total amount of physical activity in 9-yr-old children. Activity counts contributed significantly to the explained variation in TEE and was the best predictor of AEE.

  • 48.
    Ekelund, Ulf
    et al.
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Sjöström, Michael
    Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Yngve, Agneta
    Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Poortvliet, Eric
    Unit for Preventive Nutrition, Department of Medical Nutrition, Karolinska Institutet, Stockholm, Sweden.
    Nilsson, Andreas
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Fröberg, Karsten
    Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    Wedderkopp, Niels
    Institute of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
    Westerterp, Klaas
    Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
    Physical activity assessed by activity monitor and doubly labeled water in children2001In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 33, no 2, p. 275-281Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To validate the Computer Science and Application's (CSA) activity monitor for assessment of the total amount of physical activity during two school-weeks in 9-yr-old children and to develop equations to predict total energy expenditure (TEE) and activity energy expenditure (AEE) from activity counts and anthropometric variables.

    METHODS: A total of 26 children (15 boys and 11 girls, mean age 9.1 +/- 0.3 yr) were monitored for 14 consecutive days. TEE was simultaneously measured by the doubly labeled water method. Averaged activity counts (counts.min(-1)) were compared with data on: 1) TEE, 2) AEE = TEE minus basal metabolic rate (BMR; estimated from predictive equations), and 3) daily physical activity level (PAL = TEE/BMR).

    RESULTS: Physical activity determined by activity counts was significantly related to the data on energy expenditures: TEE (r = 0.39; P < 0.05), AEE (r = 0.54; P < 0.01), and PAL (r = 0.58; P < 0.01). Multiple stepwise regression analysis showed that TEE was significantly influenced by gender, body composition (body weight or fat free mass), and activity counts (R(2) = 0.54--0.60). AEE was significantly influenced by activity counts and gender (R(2) = 0.45). There were no significant differences between activity counts and PAL in discriminating among activity levels with "low" (PAL < 1.56), "moderate" (1.57 < or = PAL > or = 1.81), and "high" (PAL > 1.81) intensity.

    CONCLUSION: Activity counts from the CSA activity monitor seems to be a useful measure of the total amount of physical activity in 9-yr-old children. Activity counts contributed significantly to the explained variation in TEE and was the best predictor of AEE.

  • 49.
    Ekelund, Ulf
    et al.
    Unit for Preventive Nutrition at Novum, Department of Medical Nutrition/Biosciences, Karolinska Institutet, Stockholm, Sweden; Department of Physical Education and Health, Örebro University, Sweden.
    Yngve, Agneta
    Unit for Preventive Nutrition at Novum, Department of Medical Nutrition/Biosciences, Karolinska Institutet, Stockholm, Sweden.
    Westerterp, Klaas
    Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
    Sjöström, Michael
    Unit for Preventive Nutrition at Novum, Department of Medical Nutrition/Biosciences, Karolinska Institutet, Stockholm, Sweden.
    Energy expenditure assessed by heart rate and doubly labeled water in young athletes2002In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 34, no 8, p. 1360-1366Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To compare total energy expenditure (TEE) estimated by the FLEX heart rate (HR) method with that measured by the doubly labeled water (DLW) technique in young speed skaters. We hypothesized that the accuracy of FLEX HR-estimated TEE would be affected by a) the definition of the FLEX HR and b) the type of training regimen.

    METHODS: Eight young athletes (mean age 18.2 +/- 1.3 yr) underwent measurements during two 10-d training periods: an off-season period with voluntary training (predominantly running) and a preseason period mainly focused on skating technique training. TEE was measured simultaneously by the DLW and FLEX HR methods. FLEX HR1 was defined as the mean of the HRs during all resting calibration activities and the lowest HR during exercising calibration activities. FLEX HR2 was defined as the mean of the highest HR during resting activities and the lowest HR during exercising.

    RESULTS: ANOVA showed that FLEX HR1 was significantly lower than FLEX HR2 (mean of both periods; 77 +/- 5 vs 84 +/- 6 beats.min(-1); P = 0.004). TEE values obtained by DLW were 16.8 +/- 3.8 and 16.9 +/- 2.9 MJ.d(-1) in the two periods, respectively. TEE values calculated from FLEX HR1 were 17.8 +/- 3.6 and 17.4 +/- 2.6 MJ.d(-1), and those from FLEX HR2 17.1 +/- 3.1 and 17.0 +/- 2.7 MJ.d-1, respectively. No significant period (P = 0.83) or method (P = 0.44) effect on TEE was observed.

    CONCLUSION: FLEX HR-estimated TEE was not affected by the definition of the FLEX HR or by the type of training regimen as compared with TEE measured by the DLW method in young athletes.

  • 50.
    Ekelund, Ulf
    et al.
    Unit for Preventive Nutrition at Novum, Department of Medical Nutrition/Biosciences, Karolinska Institutet, Stockholm, Sweden; Department of Physical Education and Health, Örebro University, Sweden.
    Yngve, Agneta
    Unit for Preventive Nutrition at Novum, Department of Medical Nutrition/Biosciences, Karolinska Institutet, Stockholm, Sweden.
    Westerterp, Klaas
    Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
    Sjöström, Michael
    Unit for Preventive Nutrition at Novum, Department of Medical Nutrition/Biosciences, Karolinska Institutet, Stockholm, Sweden.
    Energy expenditure assessed by heart rate and doubly labeled water in young athletes2002In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 34, no 8, p. 1360-1366Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To compare total energy expenditure (TEE) estimated by the FLEX heart rate (HR) method with that measured by the doubly labeled water (DLW) technique in young speed skaters. We hypothesized that the accuracy of FLEX HR-estimated TEE would be affected by a) the definition of the FLEX HR and b) the type of training regimen.

    METHODS: Eight young athletes (mean age 18.2 +/- 1.3 yr) underwent measurements during two 10-d training periods: an off-season period with voluntary training (predominantly running) and a preseason period mainly focused on skating technique training. TEE was measured simultaneously by the DLW and FLEX HR methods. FLEX HR1 was defined as the mean of the HRs during all resting calibration activities and the lowest HR during exercising calibration activities. FLEX HR2 was defined as the mean of the highest HR during resting activities and the lowest HR during exercising.

    RESULTS: ANOVA showed that FLEX HR1 was significantly lower than FLEX HR2 (mean of both periods; 77 +/- 5 vs 84 +/- 6 beats.min(-1); P = 0.004). TEE values obtained by DLW were 16.8 +/- 3.8 and 16.9 +/- 2.9 MJ.d(-1) in the two periods, respectively. TEE values calculated from FLEX HR1 were 17.8 +/- 3.6 and 17.4 +/- 2.6 MJ.d(-1), and those from FLEX HR2 17.1 +/- 3.1 and 17.0 +/- 2.7 MJ.d-1, respectively. No significant period (P = 0.83) or method (P = 0.44) effect on TEE was observed.

    CONCLUSION: FLEX HR-estimated TEE was not affected by the definition of the FLEX HR or by the type of training regimen as compared with TEE measured by the DLW method in young athletes.

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