Change search
Refine search result
123456 151 - 200 of 297
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 151.
    Godhe, Manne
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Helge, Torbjörn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Forsberg, Artur
    Karlsson, Eddy
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Isokinetic muscle torque and endurance in limbs and trunk in children and adolescents: A longitudinal study2019In: Clinical and Medical Investigations, ISSN 2398-5763, Vol. 4, no 4Article in journal (Refereed)
    Abstract [en]

    Purpose: To measure isokinetic peak torque during elbow, knee and trunk extension and flexion and muscle endurance during elbow and knee extension.

    Method: Muscle endurance and peak torque were measured using Cybex methodology in totally 115 boys and 48 girls from 8 to 15 years of age most of them for five years.

    Results: Knee muscle endurance was mainly unchanged while elbow fatigue index was lightly reduced from 11 to 15 years in both sexes with no difference between sexes. From the youngest ages to adolescence peak absolute (N.m) and normalized (N.m/kg body mass) torque increases in all measures with highest increase in the trunk and lowest in elbow activities. During elbow activity boys are stronger than girls from age 11. For trunk and knee activity the sex differences start at age 14 years. Knee, elbow and trunk extension/flexion ratios as well as knee/elbow both extension and flexion ratios are mainly unchanged with increasing age with no differences between sexes.

    Conclusion: Data indicate that elbow isokinetic strength and endurance profile is partly different from corresponding data during knee and trunk activity.

  • 152.
    Godhe, Manne
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group. Militärmedicinska forskningsgruppen, Åstrandlaboratoriet.
    Helge, Torbjörn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group. Militärmedicinska forskningsgruppen, Åstrandlaboratoriet.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences. Militärmedicinska forskningsgruppen, Åstrandlaboratoriet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group. Militärmedicinska forskningsgruppen, Åstrandlaboratoriet.
    Att bära tungt - en fysiologisk analys: Kvinnor: Rapport 8.2016Report (Other academic)
    Abstract [sv]

    Sjutton kvinnliga vältränade försökspersoner, åtta stycken med vana att bära tungt och nio stycken utan sådan vana, genomförde gång på löpband och mjukt underlag i hastigheterna 3 och 5 km/tim med bärvikter i ryggsäck på 20, 35 och 50 kg.Mjukt underlag i form av blå gymnastikmattor, indikerande gång i lätt terräng, ökade energiomsättningen under både hastigheterna mellan 10 och 15 %, jämfört med hårt underlag (löpband) med en grads lutning. Energiomsättningen ökade i genomsnitt lika mycket med ökad hastighet som med ökad bärvikt. Den individuella variationen vid en given bärvikt och hastighet är mycket stor. Beroende på bärvikt och hastighet kan energiomsättningen variera med 100 %. Dessa stora variationer i energiomsättning bör uppmärksammas vid beräkning av energitilldelning via kosten vid längre militära operationer.Energiomsättningen vid tyngsta belastningen – 50 kilo bärvikt och hastigheten 5 km/tim – belastade försökspersonerna på i genomsnitt 57 % av maximal syreupptagningsförmåga. I individuella fall var belastningen 72 % av maximal syreupptagningsförmåga. Dessa höga belastningar är oacceptabelt höga för transporter under längre tid och kan vara en orsak till belastningsskador.Förmågan att bära tungt sammanfaller med ökad kroppsvikt och benmuskelstyrka. Bärförmåga för mindre vikter, högst 35 kg, sammanfaller inte med någon av ovanstående faktorer. Således, för tyngre bärvikter vid förflyttningar bör selektion av soldater ske enligt de uppmätta parametrarna, medan vad gäller lättare vikter föreligger inte samma selektionskriterier.En slutsats från resultaten av denna undersökning är den ursprungliga uttagningen till tunga arbetsuppgifter inom försvaret bör genomföras med tunga arbetsbelastningar, motsvarande de i denna undersökning. I kommande rapport sammanfattas studierna på män och kvinnors bärförmåga, likheter och olikheter mellan könen, möjliga selektionskriterier samt rekommendationer med utgångspunkt från genomförda undersökningar och resultat från olika andra undersökningar.

  • 153.
    Godhe, Manne
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Helge, Torbjörn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Physiological factors of importance for load carriage2017In: ICSPP Abstracts: Journal of Science and Medicine in Sport, November 2017 20 Supplement 2:S105, 2017, Vol. 20, no Supplement 2, p. S105-, article id 176Conference paper (Other academic)
  • 154.
    Godhe, Manne
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Helge, Torbjörn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Mattsson, C Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Physiological factors of importance for load carriageManuscript (preprint) (Other academic)
    Abstract [en]

    The energy expenditure during carrying no load, 20, 35 and 50 kg at two walking speeds, 3 and 5 km/h, was studied in 36 healthy participants, 19 men (30 ± 6 yrs, 82.5 ± 7.0 kg) and 17 women (29 ± 6 yrs, 66.1 ± 8.9 kg). Anthropometric data, leg muscle strength as well as trunk muscle endurance and muscle fibre distribution of the thigh were also obtained. To load the participant a standard backpack filled with extra weight according to the carrying weight tested was used. Extra Load Index (ELI), the oxygen uptake (VO2) during total load over no-load-exercise, was used as a proxy for load carrying ability. In addition to analyzing factors of importance for the ELI values, we also conducted mediator analyzes using sex and long term carrying experience as causal variables for ELI as the outcome value. For the lowest load (20 kg), ELI20, was correlated with body mass but no other factors. Walking at 5 km/h body mass, body height, leg muscle strength and absolute VO2max were correlated to ELI35 and ELI50, but relative VO2max, trunk muscle endurance and leg muscle fibre distribution were not. Sex as causal factor was evaluated in a mediator analyses with ELI50 as outcome. ELI50 at 5 km/h differed between the sexes. The limit for acceptable body load, 40% of VO2max (according to Astrand, 1967), was nearly reached for women carrying 35 kg (39%) and surpassed at 50 kg at 3 km/h, and for men carrying 50 kg at 5 km/h. This difference was only mediated by difference in body mass. Neither muscle fibre distribution, leg muscle strength, trunk muscle endurance and body height nor did absolute or relative VO2max explain the difference. Participants with long term experience of heavy load carrying had significant lower ELI20 and ELI50 values than those with minor or non-experience, but none of the above studied factors could explain this difference. The study showed that body mass and experience of carrying heavy loads are important factors for the ability to carry heavy loads.

  • 155.
    Gray, Stuart R
    et al.
    Strathclyde inst of pharmacy and biomedical sciences, university of strathclyde, Glasgow UK.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ferguson, Richard A
    ATP and phosphocreatine utilization in single human muscle fibres during the development of maximal power output at elevated muscle temperatures.2008In: Journal of Sports Sciences, ISSN 0264-0414, E-ISSN 1466-447X, Vol. 26, no 7, p. 701-7Article in journal (Refereed)
    Abstract [en]

    In this study, we examined the effect of muscle temperature (Tm) on adenosine triphosphate (ATP) and phosphocreatine utilization in single muscle fibres during the development of maximal power output in humans. Six male participants performed a 6-s maximal sprint on a friction-braked cycle ergometer under both normal (Tm = 34.3 degrees C, s = 0.6) and elevated (T(m) = 37.3 degrees C, s = 0.2) muscle temperature conditions. During the elevated condition, muscle temperature of the legs was raised, passively, by hot water immersion followed by wrapping in electrically heated blankets. Muscle biopsies were taken from the vastus lateralis before and immediately after exercise. Freeze-dried single fibres were dissected, characterized according to myosin heavy chain composition, and analysed for ATP and phosphocreatine content. Single fibres were classified as: type I, IIA, IIAX25 (1 - 25% IIX isoform), IIAX50 (26 - 50% IIX), IIAX75 (51 - 75% IIX), or IIAX100 (76 - 100% IIX). Maximal power output and pedal rate were both greater (P < 0.05) during the elevated condition by 258 W (s = 110) and 22 rev . min(-1) (s = 6), respectively. In both conditions, phosphocreatine content decreased significantly in all fibre types, with a greater decrease during the elevated condition in type IIA fibres (P < 0.01). Adenosine triphosphate content was also reduced to a greater (P < 0.01) extent in type IIA fibres during the elevated condition. The results of the present study indicate that after passive elevation of muscle temperature, there was a greater decrease in ATP and phosphocreatine content in type IIA fibres than in the normal trial, which contributed to the higher maximal power output.

  • 156.
    Gray, Stuart R
    et al.
    Institute of medical sciences, University of Aberdeen, Skottland.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Watson, Moira
    Ferguson, Richard A
    Skeletal muscle ATP turnover and single fibre ATP and PCr content during intense exercise at different muscle temperatures in humans.2011In: Pflügers Archiv: European Journal of Physiology, ISSN 0031-6768, E-ISSN 1432-2013, Vol. 462, no 6, p. 885-893Article in journal (Refereed)
    Abstract [en]

    The effect of temperature on skeletal muscle ATP turnover, pulmonary oxygen uptake and single fibre ATP and PCr content was studied during intense cycling exercise. Six healthy male subjects performed 6-min intense (Δ50%LT-VO(2peak)) cycling, at 60 rpm, under conditions of normal (N) and elevated muscle temperature (ET). Muscle biopsies obtained from the vastus lateralis at rest, 2 and 6 min were analysed for homogenate ATP, PCr, lactate and glycogen, allowing estimation of anaerobic ATP turnover. Freeze-dried single fibres from biopsies were characterised according to their myosin heavy chain composition (type I, IIA or IIAX) and analysed for ATP and PCr content. Pulmonary gas exchange was measured throughout. There was no difference in pulmonary oxygen uptake between the trials. The elevation of muscle temperature resulted in a lower (P < 0.05) PCr content, higher (P < 0.05) lactate content and greater (P < 0.05) anaerobic ATP turnover after 2 min of exercise. There was no effect of temperature on these measures at 6 min. In single fibres it was observed that in ET, there was a lower (P < 0.05) PCr content in type I fibres after 2 min with no differences between conditions after 6 min. The present study demonstrates that elevation of muscle temperature results in a greater anaerobic ATP turnover and type I fibre PCr degradation during the initial 2 min of intense exercise.

  • 157. Grimby, Agneta
    et al.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Sätt änkorna i rörelse - för hälsans skull!2002In: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 99, no 1-2, p. 78-80Article in journal (Other academic)
    Abstract [sv]

    Sorg är ingen sjukdom, men kan förvisso ge sådan. Ensamhet, isolering, inaktivitet, dåliga matvanor, ökad konsumtion av alkohol och tobak minskar avsevärt ambitionen att röra på sig – bildligt och bokstavligt – och är vanligt bland nyblivna änkepersoner. Kommunal hälso- och psykosocial intervention i form av tidigt stöd  och uppmuntran i sorgen – som skulle kunna bryta negativa mönster – är idag nästan obefintlig. Denna grupp människor kan ha svårt att ta till sig folkuppmaningen »Sätt Sverige i rörelse«, trots vetskapen om att regelbunden lågintensiv motion och muskelträning kan ge stora positiva hälsoeffekter. Vem antar utmaningen att  sätta änkorna i rörelse – och vem bekostar?

  • 158. Grimby, G
    et al.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Jonsdottir, I H
    Schnohr, P
    Thelle, D S
    Saltin, Bengt
    The "Saltin-Grimby Physical Activity Level Scale" and its application to health research.2015In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 25, no Suppl 4, p. 119-125Article in journal (Refereed)
    Abstract [en]

    The use of a four-level questionnaire to assess leisure time physical activity (PA) and its validation is reviewed in this paper. This questionnaire was first published in 1968 and has then been used by more than 600 000 subjects, especially in different population studies in the Nordic countries. A number of modifications to the questionnaire have been published. These are mostly minor changes, such as adding practical examples of activities to illustrate the levels of PA. Some authors have also added duration requirements that were not included for all levels of PA in the original version. The concurrent validity, with respect to aerobic capacity and movement analysis using objective measurements has been shown to be good, as has the predictive validity with respect to various risk factors for health conditions and for morbidity and mortality.

  • 159. Haglind, Charlotte
    et al.
    Ask, Sara
    von Döbeln, Ulrika
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Stenlid, Maria
    Nordenström, Anna
    Energy expenditure and lipid metabolism in very long-chain Acyl-CoA dehydrogenase (VLCAD) deficiency2015In: Molecular Genetics and Metabolism (ISSN 1096-7192), 2015, Vol. 114, no 3, p. 333-333Conference paper (Refereed)
  • 160.
    Hallgren, Mats
    et al.
    Karolinska institutet.
    Andersson, Victoria
    Center for Psychiatric Research, Stockholm.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Andréasson, Sven
    Karolinska institutet.
    Physical activity as treatment for alcohol use disorders (FitForChange): study protocol for a randomized controlled trial.2018In: Trials, ISSN 1745-6215, E-ISSN 1745-6215, Vol. 19, no 1, article id 106Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Help-seeking for alcohol use disorders (AUDs) is low and traditional treatments are often perceived as stigmatizing. Physical activity has positive effects on mental and physical health which could benefit this population. We propose to compare the effects of aerobic training, yoga, and usual care for AUDs in physically inactive Swedish adults.

    METHODS: This is a three-group, parallel, single-blind, randomized controlled trial (RCT). In total, 210 adults (aged 18-75 years) diagnosed with an AUD will be invited to participate in a 12-week intervention. The primary study outcome is alcohol consumption measure by the Timeline Follow-back method and the Alcohol Use Disorders Identification Test (AUDIT). Secondary outcomes include: depression, anxiety, perceived stress, sleep quality, physical activity levels, fitness, self-efficacy, health-related quality of life, and cognition. Blood samples will be taken to objectively assess heavy drinking, and saliva to measure cortisol. Acute effects of exercise on the urge to drink alcohol, mood, and anxiety will also be assessed.

    DISCUSSION: The treatment potential for exercise in AUDs is substantial as many individuals with the disorder are physically inactive and have comorbid health problems. The study is the first to assess the effects of physical activity as a stand-alone treatment for AUDs. Considerable attention will be given to optimizing exercise adherence. Both the feasibility and treatment effects of exercise interventions in AUDs will be discussed. The Ethical Review Board (EPN) at Karolinska Institutet has approved the study (DNR: 2017/1380-3).

    TRIAL REGISTRATION: German Clinical Trials Register, ID: DRKS00012311. Registered on 26 September 2017.

  • 161. Hallgren, Mats
    et al.
    Herring, Matthew P
    Owen, Neville
    Dunstan, David
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Helgadottir, Björg
    Nakitanda, Olivia Aya
    Forsell, Yvonne
    Exercise, Physical Activity, and Sedentary Behavior in the Treatment of Depression: Broadening the Scientific Perspectives and Clinical Opportunities.2016In: Frontiers in Psychiatry, ISSN 1664-0640, E-ISSN 1664-0640, Vol. 7, article id 36Article in journal (Refereed)
    Abstract [en]

    Research exploring links between exercise and depression now span several decades, yet several clinically relevant research questions remain unanswered. This opinion article briefly describes the status of selected research issues from the exercise depression literature and offer insights into research areas that are currently lacking. We draw particular attention to the potential of research exploring links between sedentary behavior and depression.

  • 162. Hallgren, Mats
    et al.
    Nakitanda, Olivia Aya
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Herring, Matthew P
    Owen, Neville
    Dunstan, David W
    Helgadottir, Björg
    Forsell, Yvonne
    Habitual physical activity levels predict treatment outcomes in depressed adults: A prospective cohort study.2016In: Preventive Medicine, ISSN 0091-7435, E-ISSN 1096-0260, Vol. 88, p. 53-58Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Exercise is an efficacious stand-alone therapy for mild-to-moderate depression, but little is known about the influence of physical activity levels on responses to depression treatment. This study aimed to prospectively assess the association between self-reported habitual physical activity levels and depression severity following a 12-week intervention.

    METHOD: 629 adults (75% women; aged 18-71years) with mild-to-moderate depression were recruited from primary care centres across Sweden and treated for 12weeks. The interventions included internet-based cognitive behavioural therapy (ICBT) and 'usual care' (CBT or supportive counselling). One third of all participants were taking anti-depressant medication. The primary outcome was the change in depression severity assessed using the Montgomery-Åsberg Depression Rating Scale (MADRS). Habitual physical activity levels were self-rated and based on the estimated frequency, duration and intensity of total physical activity, including planned exercise, 'during a typical week'. Prospective associations were explored using linear regression models (percentage change) with 95% confidence intervals (CI's).

    RESULTS: Following adjustment for relevant covariates, high levels of habitual physical activity were associated with larger relative reductions in depression severity compared to low physical activity (β=-9.19, 95% CI=-18.46, -0.09, p=0.052) and moderate physical activity (β=-10.81, 95% CI=-21.09, -0.53, p<0.05), respectively.

    CONCLUSION: Adults who routinely engage in high levels of physical activity respond more favourably to CBT-focused depression treatments than adults who engage in low-to-moderate levels of activity. The optimal level of physical activity associated with reductions in depression severity corresponds to consensus recommendations for maximizing general health. One limitation is the use of self-reported physical activity data.

  • 163.
    Hassmén, Peter
    et al.
    Stockholms universitet.
    Blomstrand, Eva
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Eva Blomstrand's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Newsholme, E A
    Branched-chain amino acid supplementation during 30-km competitive run: mood and cognitive performance.1994In: Nutrition (Burbank, Los Angeles County, Calif.), ISSN 0899-9007, E-ISSN 1873-1244, Vol. 10, no 5, p. 405-10Article in journal (Refereed)
    Abstract [en]

    It has been suggested that an elevated concentration of the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) in specific areas of the brain may contribute to the development of central/mental fatigue during and after sustained exercise. Supplementation with branched-chain amino acids (BCAAs) should prevent the exercise-induced increase in the plasma concentration ratio of free tryptophan to other large neutral amino acids (including BCAAs) and thereby prevent an elevation in the level of 5-HT in the brain. In this study, subjects were given either a mixture of BCAAs in a carbohydrate solution or a placebo drink that contained only carbohydrates during a 30-km cross-country race. Several tasks to measure cognitive performance were performed before and after the race. When subjects were supplied with BCAAs, their performance in the different parts of the color-word test (words, colors and color words) was improved by an average of 3-7% (p < 0.05) after exercise, whereas there was no difference in performance before and after exercise in the subjects who were given the placebo. Furthermore, the experimental group, supplied with BCAAs, maintained their performance in the shape-rotation and figure-identification tasks, whereas an impairment in performance in these tests by 25% (p < 0.05) and 15% (p < 0.05), respectively, was found in the subjects who received the placebo. Thus, BCAA supplementation seemed to have an effect on the more complex tasks, whereas no effect could be detected on the less demanding tasks. However, an intake of BCAAs during exercise modified only slightly the exercise-induced changes in mood.

  • 164. Helgadottir, B.
    et al.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Forsell, Y.
    Physical Activity Patterns of People Affected by Depressive and Anxiety Disorders: A Descriptive Study2014In: Journal of Mental Health Policy and Economics, 17, (Suppl 1), S9., 2014, Vol. 17, no Suppl 1, p. S9-Conference paper (Refereed)
  • 165.
    Helgadottir, Björg
    et al.
    Karolinska Institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Forsell, Yvonne
    Karolinska Insitutet.
    Impact of expectations on the effects of exercise on psychological distress2014In: American Journal of Health Behavior, ISSN 1087-3244, E-ISSN 1945-7359, Vol. 38, no 5, p. 560-565Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE:

    To evaluate the influence of expectations on effectiveness of exercise in reducing psychological distress.

    METHOD:

    Data came from a Swedish longitudinal population-based study consisting of 4631 people aged 20-64 years. Psychological distress was measured with the Major Depressive Inventory. Expectations (positive expectations or indifference) towards exercise were combined with exercise (regular exercise: yes or no).

    RESULTS:

    Indifferent non-exercisers had increased risk of psychological distress. Regular exercisers who were indifferent towards exercise as a self-help method were less likely to be psychologically distressed compared to exercisers with positive expectations.

    CONCLUSION:

    The results encourage systematic use of exercise in prevention and rehabilitation of persons suffering from psychological distress. People's personal expectations might not be needed for treatment effect.

  • 166.
    Helgadottir, Björg
    et al.
    PHS, EPHIR Karolinska Institutet.
    Forsell, Yvonne
    PHS, EPHIR Karolinska Institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Physical activity patterns of people affected by depressive and anxiety disorders as measured by accelerometers: a cross-sectional study2015In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 1, p. e0115894-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:

    Exercise can relieve both depressive and anxiety disorders and it is therefore of importance to establish movement patterns of mildly to moderately affected sufferers to estimate the treatment potential. The aim is to describe the physical activity patterns of people affected by mild to moderate depressive and/or anxiety symptoms using objective measures of physical activity.

    METHODS:

    The design of the study was cross-sectional using data from 165 people aged 18-65 years, with mild to moderate depressive and/or anxiety disorder symptoms (scoring ≥10 on the PHQ-9). Diagnoses were made using Mini International Neuropsychiatric Interview (MINI) and symptom severity was measured with the Montgomery-Åsberg Depression Rating Scale (MADRS). The participants wore accelerometers for a week to evaluate physical activity patterns.

    RESULTS:

    No statistically significant differences were detected between different diagnoses, though depressed participants tended to be less active and more sedentary. Only one-fifth of the sample followed public health guidelines regarding physical activity. Each one point increase in MADRS was associated with a 2.4 minute reduction in light physical activity, independent of moderate-to-vigorous physical activity and sedentary time. MADRS was positively associated with number of sedentary bouts.

    CONCLUSIONS:

    The physical activity pattern of people with depressive and/or anxiety disorders was characterized by large amounts of sedentary time and low fulfillment of physical activity guidelines. There is therefore a large treatment potential for this group by increasing exercise. The results suggest that instead of focusing exclusively on high intensity exercise for treating depressive and anxiety disorders, health care providers might encourage patients to reduce sedentary time by increasing light physical activity and decreasing the number of sedentary bouts, though further studies are needed that can determine directionality.

  • 167. Helgadóttir, Björg
    et al.
    Dunstan, David
    Owen, Neville
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Hallgren, Mats
    Forsell, Yvonne
    Changes in Physical Activity and Sedentary Behavior Associated with Exercise Interventions in Depressed Adults: 2109 Board #261 June 2, 3: 30 PM - 5: 00 PM.2016In: Medicine And Science In Sports And Exercise 2016 May; Vol. 48 (5S Suppl 1), pp. 594., 2016, Vol. 48, no 5S Suppl 1, p. 594-594Conference paper (Refereed)
    Abstract [en]

    PURPOSE: Exercise training programs are beneficial for depression, but less is known about their impact on non-intervention physical activity patterns and sedentary behavior patterns in depressed adults. We determined the extent to which participation in light-, moderate- and vigorous-intensity exercise intervention programs influenced the habitual physical activity and sedentary behavior patterns in depressed adults.

    METHODS: Accelerometer data were collected pre- and post-treatment from a subset of depressed participants randomized to one of three 12-week exercise intervention programs: light (n=21), moderate (n=25) and vigorous (n=22) exercise. Mixed models examined changes in accelerometer-measured overall time spent in sedentary, light and moderate-to-vigorous physical activity (MVPA); accumulated sedentary and MVPA bouts; and number of MVPA bouts and interruptions in sedentary time.

    RESULTS: Overall sedentary time decreased while overall light activity increased across all intervention groups but neither significantly so. The light exercise intervention group reduced their MVPA minutes (-8.22, 95% CI: -16.44, -0.01), time in MVPA bouts (-8.44, 95% CI: -14.27, -2.62), and number of activity bouts (-0.43, 95% CI: -0.77, -0.09). The moderate exercise intervention group reduced the time in MVPA bouts (-6.27, 95% CI: -11.71, -0.82) and number of sedentary interruptions (-5.79, 95% CI: -9.11, -2.46). No changes were observed for the vigorous exercise intervention group.

    CONCLUSIONS: On the whole, participating in a structured exercise intervention did not lead people who are affected by depression to significantly reduce their overall light physical activity nor to increase their sedentary time. Participation in the light and moderate exercise intervention programs was associated with reductions in overall MVPA, but this was not evident for the vigorous exercise intervention program.

  • 168.
    Helgadóttir, Björg
    et al.
    Karolinska institutet.
    Forsell, Y
    Karolinska institutet.
    Hallgren, M
    Karolinska institutet.
    Möller, J
    Karolinska institutet.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Exercise for depression: What are the long-term effects of different exercise intensities?2017In: European Journal of Public Health, Volume 27, Issue suppl_3, 1 November 2017, 2017, Vol. 27, no Suppl. 3, article id ckx187.168Conference paper (Refereed)
    Abstract [en]

    Key messages:

    • As all exercise conditions had at least a comparable effect to treatment as usual, exercise at any intensity can be recommended as treatment for mild-to-moderate depression.
    • Light intensity exercise should be emphasised more in treatment guidelines than it currently is, as its effects are potentially even greater than that of treatment as usual.
  • 169.
    Helgadóttir, Björg
    et al.
    Karolinska Institutet, Stockholm, Sweden.
    Forsell, Yvonne
    Karolinska Institutet, Stockholm, Sweden.
    Hallgren, Mats
    Karolinska Institutet, Stockholm, Sweden.
    Möller, Jette
    Karolinska Institutet, Stockholm, Sweden.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Long-term effects of exercise at different intensity levels on depression: A randomized controlled trial.2017In: Preventive Medicine, ISSN 0091-7435, E-ISSN 1096-0260, Vol. 105, p. 37-46, article id S0091-7435(17)30294-3Article in journal (Refereed)
    Abstract [en]

    Previous research has shown positive effects of exercise on depression but studies have mainly focused on the short-term effects; few have examined the long-term effect, especially with regard to differences in intensity. The aim of this study was to examine the long-term effects of prescribed exercise on depression, performed at three intensity levels. People aged 18-67years with mild to moderate depression (Patient Health Questionnaire-9 score of ≥10) participated in a single-blind, parallel randomized control trial lasting 12weeks (Sweden 2011-2013). Four arms were included: Treatment as usual (TAU, n=310), light (n=106), moderate (n=105) and vigorous exercise (n=99). Severity of depression was measured at baseline, post-treatment and 12-month follow-up using the Montgomery-Åsberg Depression Rating Scale (MADRS). Coefficients (β) and odds ratios were estimated using linear mixed models with time×group interactions. The results showed that at the 12month follow-up the light exercise group had significantly lower depression severity scores than the TAU (-1.9, 95% CI: -3.7, -0.04) and the moderate exercise group (-2.94 95% CI: -5.2, -0.7). The vigorous exercise group had significantly lower scores than the moderate exercise group only (-2.7, 95% CI: -4.9, -0.4). In conclusion, compared to usual care for depression, only light exercise resulted in significantly lower depression severity at 12-month follow-up. Both light and vigorous exercise was more effective than moderate exercise.

    TRIAL REGISTRATION: The study was registered with the German Clinical Trial Register (DRKS study ID: DRKS00008745).

  • 170. Helgadóttir, Björg
    et al.
    Owen, Neville
    Dunstan, David W.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Hallgren, Mats
    Forsell, Yvonne
    Changes in physical activity and sedentary behavior associated with an exercise intervention in depressed adults2017In: Psychology of Sport And Exercise, ISSN 1469-0292, E-ISSN 1878-5476, Vol. 30, p. 10-18Article in journal (Refereed)
    Abstract [en]

    Background Exercise is beneficial for depression, but less is known about its impact on post-intervention physical activity and sedentary behavior. The aim of this paper was to determine the extent to which participation in light-, moderate- and vigorous-intensity exercise intervention influenced habitual physical activity and sedentary behavior patterns in depressed adults. Methods Accelerometer data was collected pre- and post-intervention from depressed participants randomized to one of three 12-week intervention groups: light (n = 21), moderate (n = 25) and vigorous (n = 22) exercise. Mixed models examined changes in time spent sedentary and in light and moderate-to-vigorous physical activity (MVPA); time accumulated in sedentary and MVPA bouts; and, number of MVPA bouts and interruptions in sedentary time. Results Overall sedentary time decreased while light activity time increased across all intervention groups but not significantly so. The light exercise intervention group reduced MVPA minutes (−8.22, 95% CI: −16.44, −0.01), time in MVPA bouts (−8.44, 95% CI: −14.27, −2.62), and number of activity bouts (−0.43, 95% CI: −0.77, −0.09). The moderate exercise intervention group reduced time in MVPA bouts (−6.27, 95% CI: −11.71, −0.82) and number of sedentary interruptions (−6.07, 95% CI: −9.30, −2.84). No changes were observed for the vigorous exercise intervention group. Conclusions The exercise intervention led to an increase in overall light physical activity and decrease in sedentary time, though neither change was statistically significant. Participation in the light and moderate exercise intervention groups was associated with reductions of time in MVPA bouts, but this was not evident for the vigorous exercise intervention group.

  • 171.
    Hellénius, Mai-Lis
    et al.
    Karolinska institutet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Epidemiologi och mekanismer2013In: Långvarigt stillasittande: en hälsofara i tiden / [ed] Elin Ekblom Bak, Studentlitteratur, 2013, p. 19-45Chapter in book (Other academic)
  • 172.
    Hemmingsson, Erik
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Andersson, Gunnar
    Wallin, Peter
    Söderling, Jonas
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Blom, Victoria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Sport Psychology research group.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Objectively measured prevalence and time trends of obesity and severe obesity in 447 925 Swedish adults, 1995-20172019Conference paper (Other academic)
  • 173. Hendo, Gina
    et al.
    Jakobsson, Madeleine
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Flockhart, Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Pontén, Marjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Slutövning GMU: "Aldrig ge upp", Amf1, Berga örlogsbas: Muskelfysiologiska resultat2014Report (Other academic)
    Abstract [sv]

    Energistatus, muskelfysiologiska data och fysiskt stridsvärde studerades före och efter en 8 dygn långa grundmilitär slutövning (GMU) vid AMF-1 Berga Örlogsskolor i månadsskiftet oktober november 2013.

    Totalt deltog 105 soldater i övningen, fördelat på 3 plutoner om vardera 35 soldater. En subgrupp på 24 soldater (8 kvinnor) bestående av 8 soldater från vardera pluton studerades mer ingående.

    Medelhjärtfrekvensen för de 6 soldater (2 kvinnor) som hade i stort sett kompletta mätningar från den 187 timmar långa övningen, inklusive viloperioder, var 88 ± 7 slag/minut. Utifrån hjärtfrekvensdata beräknades den totala energiomsättningen till i genomsnitt 44 000 ± 6 600 kcal, vilket motsvarar 5 600 ± 840 kcal per dygn och 235 ± 35 kcal/tim. Total energiförbrukning var i genomsnitt 39 000 kcal för kvinnorna och 46 500 kcal för männen. I övrigt noterades inte några betydande skillnader mellan kvinnor och män. Däremot var det stora individuella variationer i energiutgift, vilka till ca hälften berodde på skillnader i kroppsvikt. Med hänsyn till kroppsvikt och buren vikt var energiförbrukningen ca 3,1 ± 0,23 kcal per timme per kg totalvikt. Den individuella variationen beror på skillnad i buren vikt, på olika uppgifter och på individuella fysiologiska skillnader.

    Utifrån beräknat energiintag blev det totala energiunderskottet under övningen 12 000-15 000 kcal, vilket är ca 1 500-2 000 kcal per dygn. Viktminskningen under övningen var 2,9 kg för kvinnor och 3,7 kg för män. Denna viktminskning på >4 % leder troligen till försämrad uthållighetsförmåga.

    Den maximala muskelstyrkan i armar och ben var i stort sett oförändrade efter övningen, liksom den beräknade maximala syreupptagningsförmågan. Däremot upplevdes ett lågintensivt cykelarbete som betydligt tyngre efter övningen. Muskeluthållighet mättes inte i denna studie.

    Ett skjutprov om 5 skott i liggande på 100 m mot en tredjedelsfigur visade 64 deltagande soldater på en försämrad träffprocent från 90,5% före till 79,4 % efter övningen. Alla soldater hade minst en träff före medan 6 soldater hade alla bom efter övningen.

    Slutsatsen från studien är att GMU-övningen resulterade i ett stort energiunderskott. Stridsvärdet, bedömt från skjutprovet var klart försämrat. Maximala fysiologiska parametrar var i stort sett oförändrade, medan skattad ansträngning och därmed uthållighetsförmåga, försämrades.

  • 174.
    Hirschberg, Angelica Lindén
    et al.
    Karolinska institutet, Stockholm, Sweden.
    Elings Knutsson, Jona
    Karolinska universitetssjukhuset, Stockholm, Sweden.
    Helge, Torbjörn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Godhe, Manne
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology.
    Ekblom, Maria
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control.
    Bermon, Stephane
    Monaco Institute of Sports Medicine, Monaco.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Effects of moderately increased testosterone concentration on physical performance in young women: a double blind, randomised, placebo controlled study2019In: British Journal of Sports Medicine, ISSN 0306-3674, E-ISSN 1473-0480Article in journal (Refereed)
    Abstract [en]

    Objective To investigate the effects of a moderate increase in serum testosterone on physical performance in young, physically active, healthy women.Methods A double blind, randomised, placebo controlled trial was conducted between May 2017 and June 2018 (ClinicalTrials.gov ID: NCT03210558). 48 healthy, physically active women aged 18–35 years were randomised to 10 weeks of treatment with 10 mg of testosterone cream daily or placebo (1:1). All participants completed the study. The primary outcome measure was aerobic performance measured by running time to exhaustion (TTE). Secondary outcomes were anaerobic performance (Wingate test) and muscle strength (squat jump (SJ), counter movement jump (CMJ) and knee extension peak torque). Hormone levels were analysed and body composition assessed by dual energy X-ray absorptiometry.Results Serum levels of testosterone increased from 0.9 (0.4) nmol/L to 4.3 (2.8) nmol/L in the testosterone supplemented group. TTE increased significantly by 21.17 s (8.5%) in the testosterone group compared with the placebo group (mean difference 15.5 s; P=0.045). Wingate average power, which increased by 15.2 W in the testosterone group compared with 3.2 W in the placebo group, was not significantly different between the groups (P=0.084). There were no significant changes in CMJ, SJ and knee extension. Mean change from baseline in total lean mass was 923 g for the testosterone group and 135 g for the placebo group (P=0.040). Mean change in lean mass in the lower limbs was 398 g and 91 g, respectively (P=0.041).Conclusion The study supports a causal effect of testosterone in the increase in aerobic running time as well as lean mass in young, physically active women.

  • 175.
    Holmberg, H-C
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Rosdahl, Hans
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Laboratory for Biomechanics and Motor Control. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, The Laboratory of Applied Sports Science (LTIV).
    Svedenhag, J
    Lung function, arterial saturation and oxygen uptake in elite cross country skiers: influence of exercise mode.2007In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 17, no 4, p. 437-44Article in journal (Refereed)
    Abstract [en]

    Arterial desaturation during exercise is common in endurance-trained athletes, a phenomenon often more pronounced when the muscle mass engaged in the exercise is large. With this background, the present study monitored seven international-level cross country skiers performing on a treadmill while running (RUN), double poling (DP; upper body exercise) and diagonal skiing (DIA; arm and leg exercise). Static and dynamic lung function tests were performed and oxygen uptake was measured during submaximal and maximal exercise. Lung function variables (including the diffusion capacity) were only 5-20% higher than reported in sedentary men. Vital capacity was considerably lower than expected from the skiers' maximal oxygen uptake (VO(2max)), but the maximal ventilation followed a linear relationship with VO(2max). None or only a mild desaturation was observed in DP, RUN and DIA. Blood lactate concentration was slightly higher in DIA than in DP but not different from RUN. In DIA, VO(2max) was 6.23 +/- 0.47 L/min (mean +/- SD), which was 3.8% and 13.9% higher than in RUN and DP, respectively, with similar peak heart rates for the three exercise modes. No relationships were present either between the degree of desaturation and pulmonary functions tests, or with peak oxygen uptakes. The low blood lactate accumulation during the exhaustive efforts contributed to the arterial oxygen saturation being mild in spite of the very high oxygen uptake observed in these skiers.

  • 176.
    Holmlund, Tobias
    et al.
    Karolinska institutet.
    Ekblom Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Franzén, Erika
    Karolinska institutet.
    Hultling, Claes
    Karolinska institutet.
    Wahman, Kerstin
    Karolinska institutet.
    Energy expenditure after spinal cord injury in people with motor-complete tetraplegia or motor-complete paraplegia.2018In: Spinal Cord, ISSN 1362-4393, E-ISSN 1476-5624, Vol. 56, no 3, p. 274-283Article in journal (Refereed)
    Abstract [en]

    STUDY DESIGN: Cross-sectional.

    OBJECTIVES: This study aimed to describe and compare VO2 and energy expenditure at rest (REE) and during standardized sedentary, non-exercise physical activity, and exercise activities, in people with motor-complete tetraplegia (C5-C8). Further, REE and energy expenditure (EE) for the different activities were compared to data from a reference group of people with motor-complete paraplegia (T7-T12).

    SETTING: Sweden.

    METHODS: The sample of people with motor-complete tetraplegia consisted of 26 adults (seven women) with SCI, C5-C8 AIS A-B. REE and EE for the different activities were measured with indirect calorimetry. The results were further compared to people with motor-complete paraplegia.

    RESULTS: Resting VO2 was 2.57 ml O2 kg-1 min-1, 2.54 for men and 2.60 for women. The VO2 or activity energy expenditure related to body weight increased three to four times during non-exercise physical activity compared to sedentary activities for the people with motor-complete tetraplegia, and up to six times during exercise activity. No significant differences were seen in resting or sedentary activity VO2 between the people with motor-complete tetraplegia and those with motor-complete paraplegia. Activities of daily life revealed no or small differences in VO2, except for setting a table, while the people with tetraplegia had ∼50% lower VO2 during exercise activities.

    CONCLUSIONS: Non-exercise physical activities of daily life may be significant for increasing total daily EE in people with motor-complete tetraplegia. This might act to motivate the individual, and might be clinically important when designing adapted lifestyle intervention programs for the target group.

  • 177.
    Holmlund, Tobias
    et al.
    Karolinska institutet.
    Ekblom-Bak, Elin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Franzén, E
    Karolinska institutet.
    Hultling, C
    Karolinska institutet.
    Wikmar, L Nilsson
    Karolinska institutet.
    Wahman, K
    Karolinska institutet.
    Energy expenditure in people with motor-complete paraplegia.2017In: Spinal Cord, ISSN 1362-4393, E-ISSN 1476-5624, Vol. 55, no 8, p. 774-781Article in journal (Refereed)
    Abstract [en]

    STUDY DESIGN: The present descriptive clinical and laboratory study is cross-sectional in design.

    OBJECTIVES: The primary aim is to describe and compare resting energy expenditure (REE) and energy expenditure (EE) during different standardized sedentary, non-exercise and exercise activities in people with motor-complete paraplegia (Th7 to Th12.). A secondary aim was to compare men and women.

    METHODS: Thirty-eight adults (10 women) with SCI, T7-T12 AIS A-B, were recruited. All the data were collected through indirect calorimetry. REE was measured in supine for 30 min after 8 h of overnight fasting. Activity energy expenditure (AEE) for activities was measured for seven minutes during sedentary, non-exercise physical activity (NEPA) and exercise activities.

    RESULTS: AEE increased four to eight times when engaging in NEPA compared to that in sedentary activities. Men had significantly higher resting oxygen uptake compared to women, 0.19 vs 0.15 l min(-1) (P=0.005), REE per 24 h, 1286 vs 1030 kcal (P=0.003) and EE during weight-bearing activities. However, these became nonsignificant after adjustment for body weight and speed of movement, with a mean resting oxygen uptake of 2.47 ml O2 per kg min(-1) for the whole group (women 2.43 and men 2.57 ml O2 kg(-1) min(-1), P=0.49).

    CONCLUSIONS: NEPA increases AEE up to eight times compared to sedentary activities. Gender differences in oxygen uptake during both rest and weight-bearing activities were diminished after adjustment for body weight. The mean resting oxygen uptake for the whole group was 2.47 ml O2 kg(-1) min(-1). These results highlight the importance, especially of NEPA, for increasing total daily EE in the target population.

  • 178.
    Ivarsson, Niklas
    et al.
    Karolinska Institutet.
    Mattsson, C. Mikael
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Cheng, Arthur J
    Karolinska Institutet.
    Bruton, Joseph D
    Karolinska Institutet.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Lanner, Johanna T
    Karolinska Institutet.
    Westerblad, Håkan
    Karolinska Institutet.
    SR Ca2+ leak in skeletal muscle fibers acts as an intracellular signal to increase fatigue resistance.2019In: The Journal of General Physiology, ISSN 0022-1295, E-ISSN 1540-7748, Vol. 151, no 4, p. 567-577, article id jgp.201812152Article in journal (Refereed)
    Abstract [en]

    Effective practices to improve skeletal muscle fatigue resistance are crucial for athletes as well as patients with dysfunctional muscles. To this end, it is important to identify the cellular signaling pathway that triggers mitochondrial biogenesis and thereby increases oxidative capacity and fatigue resistance in skeletal muscle fibers. Here, we test the hypothesis that the stress induced in skeletal muscle fibers by endurance exercise causes a reduction in the association of FK506-binding protein 12 (FKBP12) with ryanodine receptor 1 (RYR1). This will result in a mild Ca2+ leak from the sarcoplasmic reticulum (SR), which could trigger mitochondrial biogenesis and improved fatigue resistance. After giving mice access to an in-cage running wheel for three weeks, we observed decreased FKBP12 association to RYR1, increased baseline [Ca2+]i, and signaling associated with greater mitochondrial biogenesis in muscle, including PGC1α1. After six weeks of voluntary running, FKBP12 association is normalized, baseline [Ca2+]i returned to values below that of nonrunning controls, and signaling for increased mitochondrial biogenesis was no longer present. The adaptations toward improved endurance exercise performance that were observed with training could be mimicked by pharmacological agents that destabilize RYR1 and thereby induce a modest Ca2+ leak. We conclude that a mild RYR1 SR Ca2+ leak is a key trigger for the signaling pathway that increases muscle fatigue resistance.

  • 179. Johnson, Urban
    et al.
    Ivarsson, Andreas
    Karlsson, Jón
    Hägglund, Martin
    Waldén, Markus
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Rehabilitation after first-time anterior cruciate ligament injury and reconstruction in female football players: a study of resilience factors.2016In: BMC Sports Science, Medicine And Rehabilitation, ISSN 2052-1847, Vol. 8, article id 20Article in journal (Refereed)
    Abstract [en]

    Background: Most of the research in the area of psychosocial factors in rehabilitation after sports injuries has focused on risk behaviors, while relatively few studies have focused on behaviors that facilitate rehabilitation. The objective of our study was to understand the psychosocial features that characterize elite female football players who express a resilient behaviour during rehabilitation after a first-time anterior cruciate ligament (ACL) injury and reconstruction.; Methods: A qualitative method was used based on individual in-person interviews and video communication of players who incurred a first-time ACL tear during the 2012 season of the Swedish Women's Elite Football League. In total, 13 players had a first-time ACL and were interviewed post-season. The interviews were followed by a thematic content analysis. Based on this, eight players were identified as showing resilient behaviors during their rehabilitation and were included in the final analysis.; Results: Three core themes representing psychosocial factors that help players cope successfully with rehabilitation were identified: (I) constructive communication and rich interaction with significant others; (II) strong belief in the importance and efficacy of one's own actions; and (III) the ability to set reasonable goals.; Conclusions: The findings suggest three core themes of psychosocial factors that characterize first-time ACL-injured elite female football players showing resilience during rehabilitation after ACL reconstruction. Suggestions for medical teams about ways to support communication, self-efficacy, and goal-setting during the rehabilitation process, are provided.;

  • 180.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Hur ska vi fråga om fysisk aktivitet?2016In: Idrottsmedicin, ISSN 2001-3302, Vol. 35, no 3, p. 20-23Article in journal (Other academic)
  • 181.
    Kallings, Lena V
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    The organisation of promoting physical activity in health care – examples from the Nordic countries.2016In: Clinical Health Promotion - research and best practice for patients, staff and community., ISSN 2226-5864, Vol. 6, no Suppl 2, p. 27-30Article in journal (Other academic)
  • 182.
    Kallings, Lena V
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    The Swedish approach on physical activity on prescription2016In: Clinical Health Promotion - research and best practice for patients, staff and community, ISSN 2226-5864, Vol. 6, no Suppl 2, p. 31-33Article in journal (Other academic)
  • 183.
    Kallings, Lena V
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Hellénius, M-L
    Karolinska Institutet.
    Physical activity on prescription reduces sedentary behaviour for 6 months, without long term effect2014Conference paper (Refereed)
    Abstract [en]

    Objectives

    There is a lack of knowledge regarding methods to reduce sedentary behaviour. The aim of this study was to evaluate the efficacy of physical activity on prescription (PAP) in patients with overweight and abdominal obesity. PAP decrease sitting time at 6-months follow-up in this population, and data is now further analysed to study the longterm effect.

    Methods

    Six month randomised controlled study in 101 women and men (57% female, 67-68 year). All participants received a minimal intervention with brief general information on physical activity and measurement of PAL. The intervention group received in addition an individualized PAP that consisted of a patient centred counselling and a written agreement. Focus of the intervention was to reduce sedentary behaviour as well as to promote an increased PAL. Sedentary behaviour was assessed by questionnaire, the sitting item from IPAQ.

    Results

    Both groups reduced sitting time from baseline to 6-months follow-up, intervention group by 114 min/day and control group by 86 min/day. However, the changes disappeared at the long term follow-ups (Figure). There were no significant differences between the groups at either time point.

    Conclusions

    It is possible to reduce sitting time in overweight individuals. An individualized prescription of physical activity reduces sedentary behaviour for 6 months, but had no long term effects. There was no significant better effect of PAP compared to a minimal intervention. Studies with more subjects and objective methods are needed.

  • 184. Kalsen, Anders
    et al.
    Hostrup, Morten
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Karlsson, Sebastian
    Backer, Vibeke
    Bangsbo, Jens
    Inhaled Beta2-agonist Increases Power Output and Glycolysis during Sprinting in Men.2016In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 48, no 1, p. 39-48Article in journal (Refereed)
    Abstract [en]

    PURPOSE: The aim of the present study was to investigate the effect of the beta2-agonist terbutaline (TER) on power output and muscle metabolism during maximal sprint cycling.

    METHODS: In a randomized double-blind crossover design, nine moderately trained men (VO2max: 4.6±0.2 L[BULLET OPERATOR]min) conducted a 10-s cycle sprint after inhalation of either 15 mg TER or placebo (PLA). A muscle biopsy was collected before and <10 s after the sprint, and analyzed for metabolites.

    RESULTS: Mean and peak power during the sprint were 8.3±1.1 and 7.8±2.5 % higher (P<0.05) in TER than in PLA, respectively. Moreover, net rate of glycogenolysis (6.5±0.8 vs. 3.1±0.7 mmol glucosyl units kg dw s) and glycolysis (2.4±0.2 vs. 1.6±0.2 mmol glucosyl units kg dw s) were higher (P<0.05) in TER than in PLA. After the sprint, ATP was reduced in PLA (P<0.05), but not in TER. During the sprint, there was no difference in breakdown of phosphocreatine (PCr) between treatments. Estimated anaerobic ATP utilization was 9.2 ±4.0 % higher (P<0.05) in TER than in PLA. After the sprint, ATP was lowered (P <0.05) by 25.7±7.3 % in type II fibers in PLA with no reduction in TER. Before the sprint, PCr was 24.5±7.2 % lower (P <0.05) in type II fibers in TER than in PLA. In PLA, breakdown of PCr was 50.2±24.8 % higher (P <0.05) in type II than in type I fibers with no difference in TER.

    CONCLUSION: The present study shows that a terbutaline-induced increase in power output is associated with increased rates of glycogenolysis and glycolysis in skeletal muscles. Furthermore, as terbutaline counteracted a reduction in ATP in type II fibers, terbutaline may postpone fatigue development in these fibers.

  • 185.
    Khalaf, Atika
    et al.
    Högskolan i Kristianstad.
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Kowalski, Jan
    Berggren, Vanja
    Karolinska Institutet.
    Westergren, Albert
    Högskolan i Kristianstad.
    al-Hazzaa, Hazzaa
    College of Education and Obesity Research Chair, King Saud University, Saudi Arabia.
    Female University Students’ Physical Activity Levels and Associated Factors — A Cross-Sectional Study in Southwestern Saudi Arabia2013In: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 10, no 8, p. 3502-3517Article in journal (Refereed)
    Abstract [en]

    Background: The high prevalence of physical inactivity in Saudi Arabia is a growing challenge to public health. This study aimed to examine the prevalence of physical activity (PA) and associated factors among female university students. Methods: This cross-sectional study involved 663 randomly selected female university students who completed the Arab Teens Life Style questionnaire. Data included measurements of anthropometric, socioeconomic and environmental factors, as well as self-reported PA. Ordinal regression was used to identify associated factors with low, moderate and high PA levels.Results: The mean age of participants was 20.4 years (SD 1.5). Mean BMI of the students in relation to PA were 23.0, 22.9, 22.1 for high, moderate and low levels of activity, respectively. The analysis revealed significantly higher PA levels among married students, those with high educated mothers, and those who lived far from parks, and lower activity levels among underweight students. Conclusions: This study raises four important determinants for female university students’ PA levels. These factors could be of great importance in the endeavor to prevent the health-threatening increase in physical inactivity patterns and thus non-communicable diseases and obesity where the focus should be on the specific situation and needs of women in Saudi Arabia.

  • 186. Khalaf, Atika
    et al.
    Westergren, Albert
    Berggren, Vanja
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Al-Hazzaa, Hazzaa M.
    Perceived and Ideal Body Image in Young Women in South Western Saudi Arabia.2015In: Journal of Obesity, ISSN 2090-0708, E-ISSN 2090-0716, article id 697163Article in journal (Refereed)
    Abstract [en]

    Objectives. The aim of this study was to investigate perceived and ideal body image (BI) and associated factors among female university students in Saudi Arabia. Methods. This cross-sectional study included 663 university female students. Anthropometric measurements including weight, height, BMI, and BI perception (the 9-figure silhouette) were obtained. Descriptive and logistic regression analysis were conducted. Results. An agreement between actual, perceived, and ideal BI was found in 23% of the participants. Behavioral (activity levels), social (presence of obese parents and fathers’ level of education), and economic factors (households’ monthly income, number of cars in the household, and kind of residence) were positively and significantly associated with the desire to be thinner. Similarly, socioeconomic associations (number of sisters and number of cars in the household) correlated positively and significantly with the desire to be heavier. Conclusions. The whole family should rather be considered in interventions related to appearance concerns and BI discrepancies. Furthermore, campaigns targeting improvement of adolescents’ physical self-image should be a major priority of the public health sector. [ABSTRACT FROM AUTHOR]

  • 187. Khalaf, Atika
    et al.
    Westergren, Albert
    Berggren, Vanja
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Al-Hazzaa, Hazzaa M
    Prevalence and association of female weight status and dietary habits with sociodemographic factors: a cross-sectional study in Saudi Arabia.2015In: Public Health Nutrition, ISSN 1368-9800, E-ISSN 1475-2727, Vol. 18, no 5, p. 784-796Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Research about the prevalence of underweight and overweight/obesity in the Saudi Arabian female population is limited. The aim of the present study was to examine the dietary habits and the prevalence of underweight and overweight/obesity and associated factors among female university students.

    DESIGN: A cross-sectional study.

    SETTING: A university centre for female students in south-western Saudi Arabia.

    SUBJECTS: The study involved 663 randomly selected female university students who self-reported their physical activities, nutritional habits and socio-economic factors. Multiple linear and logistic regression analyses were used to identify factors associated with the students' BMI, dietary variables, underweight and overweight/obesity.

    RESULTS: The majority of the university females were normal weight (56·9 %), but a high prevalence of underweight (19·2 %) and overweight/obesity (23·8 %) occurred. Social factors significantly associated with BMI were the presence of obese parents and siblings as well as physical activity levels, marital status, number of sisters, father's level of education and more frequent intake of French fries/potato chips (>3 times/week). Several variables were found to correlate with dietary habits, underweight and overweight/obesity. Of special interest is the association between the number of siblings and the participants' BMI and dietary intake in both negative and positive ways.

    CONCLUSIONS: The findings of this research have implications for health promotion and prevention of malnutrition among college-aged females. Health-care providers and policy makers need to involve the whole family when promoting females' physical activity. The study serves as an evidence-based background for planning and implementation of interventions targeting improvement of highly educated populations' nutritional habits.

  • 188. Khalaf, Atika
    et al.
    Westergren, Albert
    Ekblom, Örjan
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Al-Hazzaa, Hazzaa M
    Berggren, Vanja
    Nurses' views and experiences of caring for malnourished patients in surgical settings in Saudi Arabia - a qualitative study.2014In: BMC Nursing, ISSN 1472-6955, E-ISSN 1472-6955, Vol. 13, p. 29-Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Although the occurrence of malnutrition in hospitals is a growing concern, little is known about how hospital staff understand the care that nurses provide to patients with malnutrition. The purpose of this study was to explore nurses' views and experiences of caring for malnourished patients in Saudi Arabia (KSA).

    METHODS: Using a qualitative explorative design, fifteen nurses were interviewed as part of a purposive sample hospital staff. The transcripts were analyzed using latent content analysis.

    RESULTS: The nurses spontaneously and consistently linked malnutrition with physical inactivity. The two main categories, which emerged, were: 'Potentials for nurses to provide good nutrition and physical activity', and 'Having the ability but not the power to promote proper nutrition and physical activity'. These arose from the subcategories: Good nursing implies providing appropriate health education; Acknowledging the Mourafiq (sitter) as a potential resource for the nursing, but also as a burden; Inadequate control and lack of influence; Cultural diversity and lack of dialog; and Views of women's weight gain in KSA society.

    CONCLUSIONS: The nurses felt they have the capacity and passion to further improve the nutrition and activity of their patients, but obstacles in the health care system are impeding these ambitions. The implications for nursing practice could be acknowledgement of the nurses' views in the clinical practice; culturally adjusted care, improved communication and enhanced language skills.

  • 189.
    Krustrup, Peter
    et al.
    Inst of exercise and sport sciences dept of human physiology, August Krogh inst, University of Copenhagen .
    Secher, Niels H
    Relu, Mihai U
    Hellsten, Ylva
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Bangsbo, Jens
    Neuromuscular blockade of slow twitch muscle fibres elevates muscle oxygen uptake and energy turnover during submaximal exercise in humans.2008In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 586, no Pt 24, p. 6037-48Article in journal (Refereed)
    Abstract [en]

    We tested the hypothesis that a greater activation of fast-twitch (FT) fibres during dynamic exercise leads to a higher muscle oxygen uptake (VO2 ) and energy turnover as well as a slower muscle on-kinetics. Subjects performed one-legged knee-extensor exercise for 10 min at an intensity of 30 W without (CON) and with (CUR) arterial injections of the non-depolarizing neuromuscular blocking agent cisatracurium. In CUR, creatine phosphate (CP) was unaltered in slow twitch (ST) fibres and decreased (P < 0.05) by 28% in FT fibres, whereas in CON, CP decreased (P < 0.05) by 33% and 23% in ST and FT fibres, respectively. From 127 s of exercise, muscle VO2 was higher (P < 0.05) in CUR compared to CON (425 +/- 25 (+/- S.E.M.) versus 332 +/- 30 ml min(-1)) and remained higher (P < 0.05) throughout exercise. Using monoexponential fitting, the time constant of the exercise-induced muscle VO2 response was slower (P < 0.05) in CUR than in CON (55 +/- 6 versus 33 +/- 5 s). During CUR and CON, muscle homogenate CP was lowered (P < 0.05) by 32 and 35%, respectively, and also muscle lactate production was similar in CUR and CON (37.8 +/- 4.1 versus 35.2 +/- 6.2 mmol). Estimated total muscle ATP turnover was 19% higher (P < 0.05) in CUR than in CON (1196 +/- 90 versus 1011 +/- 59 mmol) and true mechanical efficiency was lower (P < 0.05) in CUR than in CON (26.2 +/- 2.0 versus 30.9 +/- 1.5%). In conclusion, the present findings provide evidence that FT fibres are less efficient than ST fibres in vivo at a contraction frequency of 1 Hz, and that the muscle VO2 kinetics is slowed by FT fibre activation.

  • 190. Krustrup, Peter
    et al.
    Söderlund, Karin
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Mohr, Magni
    Bangsbo, Jens
    Slow-twitch fiber glycogen depletion elevates moderate-exercise fast-twitch fiber activity and O2 uptake.2004In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 36, no 6, p. 973-82Article in journal (Refereed)
    Abstract [en]

    PURPOSE: We tested the hypotheses that previous glycogen depletion of slow-twitch (ST) fibers enhances recruitment of fast-twitch (FT) fibers, elevates energy requirement, and results in a slow component of VO2 during moderate-intensity dynamic exercise in humans. METHODS: Twelve healthy, male subjects cycled for 20 min at approximately 50% VO2max with normal glycogen stores (CON) and with exercise-induced glycogen depleted ST fibers (CHO-DEP). Pulmonary VO2 was measured continuously and single fiber, muscle homogenate, and blood metabolites were determined repeatedly during each trial. RESULTS: ST fiber glycogen content decreased (P < 0.05) during CON (293 +/- 24 to 204 +/- 17 mmol x kg d.w.), but not during CHO-DEP (92 +/- 22 and 84 +/- 13 mmol x kg d.w.). FT fiber CP and glycogen levels were unaltered during CON, whereas FT fiber CP levels decreased (29 +/- 7%, P < 0.05) during CHO-DEP and glycogen content tended to decrease (32 +/- 14%, P = 0.07). During CHO-DEP, VO2 was higher (P < 0.05) from 2 to 20 min than in CON (0-20 min:7 +/- 1%). Muscle lactate, pH and temperature, ventilation, and plasma epinephrine were not different between trials. From 3 to 20 min of CHO-DEP, VO2 increased (P <0.05) by 5 +/- 1% from 1.95 +/- 0.05 to 2.06 +/- 0.08 L x min but was unchanged during CON. In this exercise period, muscle pH and blood lactate were unaltered in both trials. Exponential modeling revealed a slow component of VO2 equivalent to 0.12 +/- 0.04 L x min during CHO-DEP. CONCLUSION: This study demonstrates that previous glycogen depletion of ST fibers enhances FT fiber recruitment, elevates O2 cost, and causes a slow component of VO2 during dynamic exercise with no blood lactate accumulation or muscular acidosis. These findings suggest that FT fiber recruitment elevates energy requirement of dynamic exercise in humans and support an important role of active FT fibers in producing the slow component of VO2

  • 191.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Effects of dietary nitrate on oxygen cost during exercise2007In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 191, no 1, p. 59-66Article in journal (Refereed)
    Abstract [en]

    AIM: Nitric oxide (NO), synthesized from l-arginine by NO synthases, plays a role in adaptation to physical exercise by modulating blood flow, muscular contraction and glucose uptake and in the control of cellular respiration. Recent studies show that NO can be formed in vivo also from the reduction of inorganic nitrate (NO(3) (-)) and nitrite (NO(2) (-)). The diet constitutes a major source of nitrate, and vegetables are particularly rich in this anion. The aim of this study was to investigate if dietary nitrate had any effect on metabolic and circulatory parameters during exercise. METHOD: In a randomized double-blind placebo-controlled crossover study, we tested the effect of dietary nitrate on physiological and metabolic parameters during exercise. Nine healthy young well-trained men performed submaximal and maximal work tests on a cycle ergometer after two separate 3-day periods of dietary supplementation with sodium nitrate (0.1 mmol kg(-1) day-1) or an equal amount of sodium chloride (placebo). RESULTS: The oxygen cost at submaximal exercise was reduced after nitrate supplementation compared with placebo. On an average Vo(2) decreased from 2.98 +/- 0.57 during CON to 2.82 +/- 0.58 L min(-1) during NIT (P < 0.02) over the four lowest submaximal work rates. Gross efficiency increased from 19.7 +/- 1.6 during CON to 21.1 +/- 1.3% during NIT (P < 0.01) over the four lowest work rates. There was no difference in heart rate, lactate [Hla], ventilation (VE), VE/Vo(2) or respiratory exchange ratio between nitrate and placebo during any of the submaximal work rates. CONCLUSION: We conclude that dietary nitrate supplementation, in an amount achievable through a diet rich in vegetables, results in a lower oxygen demand during submaximal work. This highly surprising effect occurred without an accompanying increase in lactate concentration, indicating that the energy production had become more efficient. The mechanism of action needs to be clarified but a likely first step is the in vivo reduction of dietary nitrate into bioactive nitrogen oxides including nitrite and NO.

  • 192.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    The low intracellular oxygen tension during exercise is a function of limited oxygen supply and high mitochondrial oxygen affinity: A letter to the editor2012In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 112, no 11, p. 3935-3936Article in journal (Other academic)
    Abstract [en]

    A letter to the editor is presented in response to an article on muscle intracellular oxygenation during exercise published in a previous issue of the journal.

  • 193.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom'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.
    Mitochondrial oxygen affinity predicts basal metabolic rate in humans2011In: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 25, no 8, p. 2843-52Article in journal (Refereed)
    Abstract [en]

    The basal metabolic rate (BMR) is referred to as the minimal rate of metabolism required to support basic body functions. It is well known that individual BMR varies greatly, even when correcting for body weight, fat content, and thyroid hormone levels, but the mechanistic determinants of this phenomenon remain unknown. Here, we show in humans that mass-related BMR correlates strongly to the mitochondrial oxygen affinity (p50(mito); R(2)=0.66, P=0.0004) measured in isolated skeletal muscle mitochondria. A similar relationship was found for oxygen affinity and efficiency during constant-load submaximal exercise (R(2)=0.46, P=0.007). In contrast, BMR did not correlate to overall mitochondrial density or to proton leak. Mechanistically, part of the p50(mito) seems to be controlled by the excess of cytochrome c oxidase (COX) protein and activity relative to other mitochondrial proteins. This is illustrated by the 5-fold increase in p50(mito) after partial cyanide inhibition of COX at doses that do not affect maximal mitochondrial electron flux through the ETS. These data suggest that the interindividual variation in BMR in humans is primarily explained by differences in mitochondrial oxygen affinity. The implications of these findings are discussed in terms of a trade-off between aerobic efficiency and power.

  • 194.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences.
    Weitzberg, Eddie
    Lundberg, Jon
    Effects of dietary nitrate on blood pressure in healthy volunteers2006In: New England Journal of Medicine, ISSN 0028-4793, E-ISSN 1533-4406, Vol. 28, no 355(26), p. 2792-3Article in journal (Refereed)
    Abstract [en]

    To the Editor:

    Nitric oxide, generated by nitric oxide synthase, is a key regulator of vascular integrity. This system is dysfunctional in many cardiovascular disorders, including hypertension. A fundamentally different pathway for the generation of nitric oxide was recently described in which the anions nitrate (NO3 ) and nitrite (NO2 ) are converted into nitric oxide and other bioactive nitrogen oxides.1-3 Nitrate is abundant in our diet, and particularly high levels are found in many vegetables.3

    We examined the effect of 3-day dietary supplementation with either sodium nitrate (at a dose of 0.1 mmol per kilogram of body weight per day) or placebo (sodium chloride, at a dose of 0.1 mmol per kilogram per day) on blood pressure in 17 physically active, healthy volunteers, none of whom smoked (15 men and 2 women; mean age, 24 years). The study had a randomized, double-blind, crossover design with two different treatment periods during which the subjects received either nitrate or placebo; the treatment periods were separated by a washout period of at least 10 days. The compounds were dissolved in water and could not be distinguished by taste or appearance. During the two treatment periods, the subjects were instructed to avoid all foods with a moderate or high nitrate content.3

    Systolic blood pressure Effects of 3-Day Dietary Supplementation with Inorganic Nitrate or Placebo on Systolic (Panel A) and Diastolic (Panel B) Blood Pressure in 17 Healthy Volunteers.) and pulse rate did not change significantly after nitrate supplementation, as compared with placebo supplementation. However, the diastolic blood pressure was on average 3.7 mm Hg lower after nitrate supplementation than after placebo supplementation (P<0.02) (Figure 1B), and the mean arterial pressure was 3.2 mm Hg lower (P<0.03). Plasma nitrate levels were higher after nitrate ingestion than after placebo ingestion (mean [±SD], 178±51 and 26±11 μM, respectively; P<0.001), as were plasma nitrite levels (219±105 and 138±38 nM, respectively; P<0.01).

    The daily nitrate dose used in the study corresponds to the amount normally found in 150 to 250 g of a nitrate-rich vegetable such as spinach, beetroot, or lettuce. It is clear from earlier studies, such as the Dietary Approaches to Stop Hypertension (DASH) trial, that a diet rich in fruits and vegetables can reduce blood pressure,4,5 but attempts to modify single nutrients have been inconsistent. Therefore, it has been argued that the effect of any individual nutrient is too small to detect in trials. In our study, reduced blood pressure was associated with nitrate supplementation alone; this effect was evident in young normotensive subjects. In fact, it was similar to that seen in the healthy control group in the DASH study.4 The exact mechanism behind the blood-pressure–lowering effect of nitrate needs to be clarified in future studies.

    We conclude that short-term dietary supplementation with inorganic nitrate reduces diastolic blood pressure in healthy young volunteers.

  • 195.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Anderson, Martin
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Nyström, Thomas
    Cardiorespiratory fitness predicts insulin action and secretion in healthy individuals.2012In: Metabolism: Clinical and Experimental, ISSN 0026-0495, E-ISSN 1532-8600, Vol. 61, no 1, p. 12-6Article in journal (Refereed)
    Abstract [en]

    Long-term cardiorespiratory fitness (CRF) and the development of type 2 diabetes mellitus are inversely correlated. Here, we examined the relationships between peak oxygen uptake (VO(2)peak), on the one hand, and glucose infusion rate at rest (GIR(rest)) and during exercise (GIR(exercise)), as well as insulin secretion (both the early and late phases of response [area under the curve {AUC}(insulin)]), on the other. Eight male and 4 female healthy, lean, nonsmoking volunteers were recruited. The VO(2)peak was measured during graded exercise on a cycle ergometer until exhaustion was reached. The GIR(rest) and GIR(exercise) were determined using a euglycemic-hyperinsulinemic clamp, and insulin secretion at rest was evaluated with an intravenous glucose tolerance test. The VO(2)peak correlated positively to GIR(rest) (r = 0.81, P = .001) and GIR(exercise) (r = 0.87, P < .001) and negatively to AUC(insulin) (r = -0.64, P = .03). The respiratory exchange ratio (RER) during insulin infusion was positively correlated to GIR(rest) (r = 0.83, P < .001) and GIR(exercise) (r = 0.86, P < .01) and negatively correlated to both the early insulin response (r = -0.86, P < .0001) and AUC(insulin) (r = -0.87, P = .001). The VO(2)peak accounted for 45% of the variability in RER (R(2) = 0.45, P = .035). In this healthy population, CRF and RER were highly correlated to insulin sensitivity and secretion, as well as to the ability to alter the substrate being oxidized during exercise. These findings highlight the importance of good CRF to maintaining normal insulin action.

  • 196.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Research group for Mitokondriell funktion och metabolisk kontroll. Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's research group.
    Mattsson, Mikael
    Individen i idrotten2019In: Idrott och Kunskap, ISSN 1652-6961, Vol. 5, no 5, p. 14-21Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Sedan urminnes tider har det varit känt att olika träningsupplägg fungerar bättre för vissa idrottare än för andra. Med modern datainsamling och analytiska tekniker kan vi integrera mätvärden från träning, prestation och resultat, samt subjektiva och biologiska markörer så att de från en sammantagen bild kan ge rekommendationer anpassade till den specifika individen. Detta gör att idrottarna inte bara kan träna, återhämta sig mer effektivt och prestera bättre, utan även undvika skador och sjukdomar.

    Artikeln belyser att många professionella team samlar in så mycket mätvärden att de lider av en ”data-tsunami”, och hur den senaste vetenskapen och analytiska metoder, inklusive AI och djupinlärning, kan optimera datainsamling och analys för att minimera skador och förbättra prestationen.

  • 197.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Schiffer, Tomas A
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Mattsson, Mathias P
    Checa, Antonio
    Wheelock, Craig E
    Nyström, Thomas
    Lundberg, Jon O
    Weitzberg, Eddie
    Dietary nitrate reduces resting metabolic rate: a randomized, crossover study in humans.2014In: American Journal of Clinical Nutrition, ISSN 0002-9165, E-ISSN 1938-3207, Vol. 99, no 4, p. 843-50Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Nitrate, which is an inorganic anion abundant in vegetables, increases the efficiency of isolated human mitochondria. Such an effect might be reflected in changes in the resting metabolic rate (RMR) and formation of reactive oxygen species. The bioactivation of nitrate involves its active accumulation in saliva followed by a sequential reduction to nitrite, nitric oxide, and other reactive nitrogen species.

    OBJECTIVE: We studied effects of inorganic nitrate, in amounts that represented a diet rich in vegetables, on the RMR in healthy volunteers.

    DESIGN: In a randomized, double-blind, crossover study, we measured the RMR by using indirect calorimetry in 13 healthy volunteers after a 3-d dietary intervention with sodium nitrate (NaNO3) or a placebo (NaCl). The nitrate dose (0.1 mmol · kg(-1) · d(-1)) corresponded to the amount in 200-300 g spinach, beetroot, lettuce, or other vegetable that was rich in nitrate. Effects of direct nitrite exposure on cell respiration were studied in cultured human primary myotubes.

    RESULTS: The RMR was 4.2% lower after nitrate compared with placebo administration, and the change correlated strongly to the degree of nitrate accumulation in saliva (r(2) = 0.71). The thyroid hormone status, insulin sensitivity, glucose uptake, plasma concentration of isoprostanes, and total antioxidant capacity were unaffected by nitrate. The administration of nitrite to human primary myotubes acutely inhibited respiration.

    CONCLUSIONS: Dietary inorganic nitrate reduces the RMR. This effect may have implications for the regulation of metabolic function in health and disease.

  • 198.
    Larsen, Filip J
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Weitzberg, Eddie
    Lundberg, Jon O
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Dietary nitrate reduces maximal oxygen consumption while maintaining work performance in maximal exercise.2010In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 48, no 2, p. 342-7Article in journal (Refereed)
    Abstract [en]

    The anion nitrate-abundant in our diet-has recently emerged as a major pool of nitric oxide (NO) synthase-independent NO production. Nitrate is reduced stepwise in vivo to nitrite and then NO and possibly other bioactive nitrogen oxides. This reductive pathway is enhanced during low oxygen tension and acidosis. A recent study shows a reduction in oxygen consumption during submaximal exercise attributable to dietary nitrate. We went on to study the effects of dietary nitrate on various physiological and biochemical parameters during maximal exercise. Nine healthy, nonsmoking volunteers (age 30+/-2.3 years, VO(2max) 3.72+/-0.33 L/min) participated in this study, which had a randomized, double-blind crossover design. Subjects received dietary supplementation with sodium nitrate (0.1 mmol/kg/day) or placebo (NaCl) for 2 days before the test. This dose corresponds to the amount found in 100-300 g of a nitrate-rich vegetable such as spinach or beetroot. The maximal exercise tests consisted of an incremental exercise to exhaustion with combined arm and leg cranking on two separate ergometers. Dietary nitrate reduced VO(2max) from 3.72+/-0.33 to 3.62+/-0.31 L/min, P<0.05. Despite the reduction in VO(2max) the time to exhaustion trended to an increase after nitrate supplementation (524+/-31 vs 563+/-30 s, P=0.13). There was a correlation between the change in time to exhaustion and the change in VO(2max) (R(2)=0.47, P=0.04). A moderate dietary dose of nitrate significantly reduces VO(2max) during maximal exercise using a large active muscle mass. This reduction occurred with a trend toward increased time to exhaustion implying that two separate mechanisms are involved: one that reduces VO(2max) and another that improves the energetic function of the working muscles.

  • 199.
    Larsen, Filip
    et al.
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Schiffer, TA
    Borniquel, S
    Sahlin, Kent
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Research group for Mitokondriell funktion och metabolisk kontroll.
    Ekblom, Björn
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Björn Ekblom's research group.
    Lundberg, JO
    Weitzberg, E
    Dietary inorganic nitrate improves mitochondrial efficiency in humans.2011In: Cell Metabolism, ISSN 1550-4131, Vol. 13, no 2, p. 149-159Article in journal (Refereed)
    Abstract [en]

    Nitrate, an inorganic anion abundant in vegetables, is converted in vivo to bioactive nitrogen oxides including NO. We recently demonstrated that dietary nitrate reduces oxygen cost during physical exercise, but the mechanism remains unknown. In a double-blind crossover trial we studied the effects of a dietary intervention with inorganic nitrate on basal mitochondrial function and whole-body oxygen consumption in healthy volunteers. Skeletal muscle mitochondria harvested after nitrate supplementation displayed an improvement in oxidative phosphorylation efficiency (P/O ratio) and a decrease in state 4 respiration with and without atractyloside and respiration without adenylates. The improved mitochondrial P/O ratio correlated to the reduction in oxygen cost during exercise. Mechanistically, nitrate reduced the expression of ATP/ADP translocase, a protein involved in proton conductance. We conclude that dietary nitrate has profound effects on basal mitochondrial function. These findings may have implications for exercise physiology- and lifestyle-related disorders that involve dysfunctional mitochondria.

  • 200. Leijon, M.
    et al.
    Kallings, Lena
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Faskunger, J.
    Lärum, G.
    Börjesson, Mats
    Swedish School of Sport and Health Sciences, GIH, Department of Sport and Health Sciences, Åstrand Laboratory of Work Physiology, Björn Ekblom's and Mats Börjesson's research group.
    Ståhle, A.
    Thúc đẩy hoạt động thể lực Chương 4. [Promoting physical activity. Chapter 4].2012In: HOạT ĐộNG THể LựC TRONG PHÒNG VÀ ĐIềU TRị BệNH. [Professional associations for physical activity YFA. Physical Activity in the Prevention and Treatment of Disease (In Vietnamese)]., Nhà xuất bản Y học Hà Nội, năm , 2012, p. 93-114Chapter in book (Other academic)
123456 151 - 200 of 297
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf