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  • 101.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Björklund, Glenn
    Rydh, F
    VO2 slow component abolished after warm up with apneas2009In: 14th Annual Congress of the ECSS in Oslo, Norway 24-27 June 2009, 2009Conference paper (Refereed)
  • 102.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matthew
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Increase in hematocrit after short and long term apnea training2005In: Blue 2005. Human Behaviour and Limits in Underwater Environments. Abstract book: International Conference organised by: CNR Institute of Clinical Physiology, Pisa - Italy Apnea Academy - Italy University of Chieti - Italy. Pisa December 1-4 2005., Pisa: CNR Institute of Clinical Physiology , 2005, p. 57-58Conference paper (Refereed)
  • 103.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matthew
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Increases in diving response, hematocrit and asphyxia tolerance after apnea training2005Conference paper (Other scientific)
  • 104.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Engan, H
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Increase in reticulocyte count after 2 weeks of apne training: Meeting abstract2009In: Journal of Physiological Sciences, Suppl 1, 2009, Tokyo: Springer, 2009, p. 496-496Conference paper (Refereed)
  • 105.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Gislén, Anna
    Dept Cell and Organism Biol, Lund Univ..
    Superior underwater vision shows unexpected adaptability of the human eye2011In: Was man more aquatic in the past?: Fifty Years after Alister Hardy – Waterside Hypothesis of Human Evolution. / [ed] Vaneechoutte M, Kuliukas A, Verhaegen M, Bentham eBooks, 2011Chapter in book (Refereed)
  • 106.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Reimers, J
    Speed of spleen volume changes evoked by serial apneas2005In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 93, no 4, p. 447-452Article in journal (Refereed)
    Abstract [en]

    Diving mammals may enhance dive duration by injecting extra erythrocytes into the circulation by spleen contraction. This mechanism may also be important for apneic duration in humans. We studied the speed and magnitude of spleen volume changes evoked by serial apneas, and the associated changes in hematocrit (Hct) and hemoglobin (Hb) concentration, diving response and apneic duration. Three maximal apneas separated by 2 min rest elicited spleen contraction in all ten subjects, by a mean of 49 (27) ml (18%; P<0.001). During the same period, Hct and Hb rose by 2.2 and 2.4% respectively (P<0.01 and P<0.001), and apneic duration rose by 20 s (22% P<0.05). The mean heart rate reduction of the diving response was 15%, which remained the same throughout the apnea series. While the diving response was completely reversed between the apneas, spleen size was not recovered until 8–9 min after the final apnea corresponding with recovery of Hct and Hb. Thus, although the spleen contraction may be associated with the cardiovascular diving response, it is likely to be triggered by different mechanisms, and it may remain activated between dives spaced by short pauses. The two adjustments may provide a fast, quickly reversed, and a slow, but long-lasting, way of shifting to a diving mode in humans

  • 107.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Reimers, J
    Spleen volume changes evoked by serial apneas: Underwater and Baromedical Society (EUBS) meeting Copenhagen2003Conference paper (Other academic)
  • 108.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Holmström, Pontus
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Mulder, Eric
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Limbu, Prakash
    Nepalese Army Institute of Health Sciences, Kathmandu, Nepal.
    Schagatay, Fanny Saga
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Engan, Harald
    LHL Health, Norway.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Nursing Sciences.
    Spleen Volume and Contraction During Apnea in Mt. Everest Climbers and Everest Base Camp Trekkers2020In: High Altitude Medicine & Biology, ISSN 1527-0297, E-ISSN 1557-8682, Vol. 21, no 1, p. 84-91Article in journal (Refereed)
    Abstract [en]

    The human spleen can contract and transiently boost the blood with stored erythrocytes. We measured spleen volume and contraction during apneas in two groups, each containing 12 Caucasian participants (each 3 women): one group planning to summit Mt. Everest (8848 m; "Climbers") and another trekking to Everest Base Camp (5300 m; "Trekkers"). Tests were done in Kathmandu (1370 m) 1-3 days after arrival, before the Climb/Trek. Age, height, weight, vital capacity, resting heart rate, and arterial oxygen saturation were similar between groups (not significant). After 15 minutes of sitting rest, all participants performed a 1-minute apnea and, after 2 minutes of rest, 1 maximal duration apnea was performed. Six of the climbers did a third apnea and hemoglobin concentration (Hb) was measured. Three axial spleen diameters were measured by ultrasonic imaging before and after the apneas for spleen volume calculation. Mean (standard deviation) baseline spleen volume was larger in Climbers [367 (181) mL] than in Trekkers [228 (70) mL; p = 0.022]. Spleen contraction occurred during apneas in both groups, with about twice the magnitude in Climbers. Three apneas in six of the Climbers resulted in a spleen volume reduction from 348 (145) to 202 (91) mL (p = 0.005) and an Hb elevation from 147.9 (13.1) to 153.3 (11.3) g/L (p = 0.024). Maximal apneic duration was longer in Climbers [88 (23) seconds vs. 67 (18) seconds in Trekkers; p = 0.023]. We concluded that a large spleen characterizes Climbers, suggesting that spleen function may be important for high-altitude climbing performance.

  • 109.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Hubinette, A
    Klockervold, I
    Björklund, Glenn
    Enqvist, Jonas
    Holmberg, Hans-Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The effects of 70 days of skiing across Greenland on body composition, cold- and altitude tolerance and work performance in two elderly men2009In: 14th Annual Congress of the ECSS in Oslo, Norway 24-27 June 2009, 2009Conference paper (Refereed)
  • 110.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Hubinette, Anna
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Engan, Harald K.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Stenfors, Nikolai
    Department of Public Health and Clinical Medicine, Unit of Research, Education and Development - Östersund, Umeå University, Umeå, Sweden.
    Exercise induce hemoconcentration following spleen contraction in subjects with COPD2015In: COPD Research and practice, ISSN 2054-9040, Vol. 1, p. 1-7, article id 13Article in journal (Refereed)
    Abstract [en]

    The blood-boosting spleen contraction represents a potential protective response to hypoxia by raising the blood gas storage capacity. Human spleen contraction has been observed during exercise, apnea and simulated altitude resulting in ejection of stored red blood cells into circulation. High-altitude exposure has been shown to increase spleen contraction suggesting that long-term hypoxia may improve the response in humans. Subjects with COPD are often exposed to hypoxia, which limits their physical performance. However, it is not known if spleen contraction occurs in subjects with COPD. Our aim was to reveal whether subjects with COPD recruit the spleen erythrocyte reserve during mild exercise.

    Methods

    SpO2, spleen volume and Hb were measured before and after 6 min walking test (6MWT) in 24 subjects with COPD. Results were analyzed for all subjects pooled and for subject groups with resting SpO2 above and below 90 % separated and expressed as mean.

    Results

    6MWT reduced SpO2 from 91 to 83 % and spleen volume from 254 to 181 mL, while Hb increased from 150 to 154 g/L (p = 0.001 for all). Compared to subjects with SpO2 > 90 %, the group with SpO2 < 90 % displayed the largest resting spleen volume (339 vs 202 mL; p = 0.001) and the most pronounced spleen volume reduction (139 vs 40 mL; p = 0.007).

    Conclusion

    Exercise with hypoxia evokes spleen contraction in subjects with COPD and may represent a protective response during periods of hypoxia. The larger spleen volume and more pronounced contraction in the most hypoxic subjects may suggest long-term adaptation to hypoxia.

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  • 111.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Johansson, Orio
    Lund University.
    Abrahamsson, Erik
    Lund University.
    Diving Response and Lung Capacity of Philippine Sama-Bajau Professional Breath-Hold Divers2017In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 219, no S710, article id P-66Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: Freedivers possess several special physiological features and have been reported to have stronger diving response and larger vital capacity (VC) than non-divers. Several populations in South-East Asia live as marine hunter-gatherers dependent upon daily freediving with little equipment. One group is the Sama-Bajau in Indonesia, Philippines and Malaysia. Our aim was to investigate the diving response and lung physiology of the Sama-Bajau breath-hold diving population in the Phillipines, which has not previously been studied. 

    MATERIALS AND METHODS: Nine male professional breath-hold divers were recruited from a Sama-Bajau diving community near Davao in the Philippines. Their mean(SD) age was 27(3)years, height 166(2)cm, and weight 58(2)kg. Divers made simulated dives by maximal apneas with face immersion in cool water, while heart-rate (HR) was recorded to determine the diving response by the HR reduction. Lung variables were measured using a portable spirometer, and diving time and depth of working dives in the sea were logged.

    RESULTS: Mean(SE) HR-reduction was 39(3)%, at a maximal voluntary apnea of 67(7)s duration. VC was 3.9(0.6)L (96% of predicted for a Malaysian population, NS) and forced expiratory volume in the 1st second/forced VC was 89.6(3.4)% (105% of predicted, P<0.05). Maximal diving depth was 15 m, and mean depth 5(2) m. Diving shifts lasted 2-3h, with approximately 50% of the time spent underwater.

    CONCLUSION: The diving response was more pronounced than in non divers but in the range typical for breath-hold divers. VC was similar to predicted for non-divers but smaller than in e.g. competition divers. FEV1/FVC was slightly higher than in the normal population. We concluded that long term daily "natural" diving to 5-15m does not increase lung volume, but may have some effects on lung function.

  • 112.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Johansson, Orio
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Engan, Harald
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Training effects in human breath-hold diving2012Conference paper (Other academic)
  • 113.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lodin, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Lung volume and diving performance in elite apneists2007In: Proceedings. 33rd EUBS Annual Scientific Meeting, Sharm el Sheik, Egypt, 8-15 September 2007, 2007Conference paper (Refereed)
    Abstract [en]

    Background The ability to perform extended apnea depends mainly on 3 factors: a) the total body gas storage capacity (in blood, tissues and lungs), b) the tolerable levels of hypoxia and hypercapnia, and c) the ability to restrict metabolism (work economy and diving response). To maximize lung volume is an obvious way to increase a), and large lungs with small residual volume are also beneficial for reaching great depths without risking squeeze. Negative effects of large lung volume may be increased surface buoyancy and high intra-thoracic pressure, with a negative effect on venous return, risk of syncope, and a decreased diving response, which is important for c). However, trained divers have previously been reported to have large lungs (Carey et al 1956) and the positive effects may outweigh the disadvantages. The present study evaluated if large lungs are associated with good results in competitive apneic diving. Methods Height, weight and vital capacity (VC), without lung packing, were recorded in 14 male apneic divers participating in the apnea world championship in Hurgada 2006. Their previous apnea training experience was 5.8(1.2) years. Individual total competition scores i.e. the accumulated points from dives of maximal depth, time and distance, were compared with lung volumes. Results Subject mean(SE) height was 184(2) cm, weight was 82(3) kg and VC was 7.3(0.3) L. Mean dive performance of these subjects was 75(4) m for constant weight deep diving, 5 min 53(39) s for static apnea (resting submersion) and 139(13) m for dynamic apnea (pool distance). A Pearson´s correlation test revealed that lung volume was positively correlated with the total competition score (r = 0.54; P<0.05). Individual height and weight were not correlated with performance. Conclusions We conclude that large lung volume may contribute to successful apnea performance in humans and that any negative effects are outweighed by benefits.

  • 114.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Effect of fasting on static apnea performance2010In: Proceedings from the European Underwater Baromed Society 36th Annual Meeting Istanbul, Turkey 14-18 Sept 2010, 2010Conference paper (Refereed)
  • 115.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Fasting improves static apnea performance in elite divers without enhanced risk of syncope2014In: European Journal of Sport Science, ISSN 1746-1391, E-ISSN 1536-7290, Vol. 14, no Suppl 1, p. S157-S164Article in journal (Refereed)
    Abstract [en]

    In competitive apnea divers, the nutritional demands may be essentially different from those of, for example, endurance athletes, where energy resources need to be maximised for successful performance. In competitive apnea, the goal is instead to limit metabolism, as the length of the sustainable apneic period will depend to a great extent on minimising oxygen consumption. Many but not all elite divers fast before performing static apnea in competition. This may increase oxygen consumption as mainly lipid stores are metabolised but could also have beneficial effects on apneic duration. Our aim was to determine the effect of over-night fasting on apnea performance. Six female and seven male divers performed a series of three apneas after eating and fasting, respectively. The series consisted of two 2-min apneas spaced by 3 min rest and, after 5 min rest, one maximal effort apnea. Apneas were performed at supine rest and preceded by normal respiration and maximal inspiration. Mean (±SD) time since eating was 13 h (±2 h 43 min) for the fasting and 1 h 34 min (±33 min) for the eating condition (P < 0.001). Mean blood glucose was 5.1 (±0.4) mmol/L after fasting and 5.9 (±0.7) mmol/L after eating (P<0.01). Lung volumes were similar in both conditions (NS). For the 2-min apneas, nadir SaO2 during fasting was 95 (±1)% and 92 (±2)% (P < 0.001) on eating and ETCO2 was lower in the fasting condition (P < 0.01) while heart rate (HR) during apnea was 74 (±10) bpm for fasting and 80 (±10) bpm for eating conditions (P < 0.01). Maximal apnea durations were 4 min 41 s (±43 s) during fasting and 3 min 51 s (±37 s) after eating (P < 0.001), and time without respiratory contractions was 31 s (25%) longer after fasting (P < 0.01). At maximal apnea termination, SaO2 and ETCO2 were similar in both conditions (NS) and apneic HR was 63 (±9) bpm for fasting and 70 (±10) bpm for eating (P < 0.01). The 22% longer apnea duration after fasting with analogous end apnea SaO2 levels suggests that fasting is beneficial for static apnea performance in elite divers, likely via metabolism-limiting mechanisms. The oxygen-conserving effect of the more pronounced diving response and possibly other metabolism-limiting mechanisms related to fasting apparently outweigh the enhanced oxygen consumption caused by lipid metabolism.

  • 116.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Abrahamsson, Erik
    Lunds Universitet.
    Underwater working time in two groups of traditional apneic divers in South East Asia.2010In: Proceedings from the European Underwater Baromed Society 36th Annual Meeting Istanbul, Turkey 14-18 Sept 2010, 2010, p. 0145-Conference paper (Refereed)
  • 117.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Abrahamsson, Erik
    Lund Univ, Dept Sociol, Div Social Anthropol, Lund, Sweden.
    Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau2011In: Diving and hyperbaric medicine, ISSN 1833-3516, Vol. 41, no 1, p. 27-30Article in journal (Refereed)
    Abstract [en]

    (Schagatay E, Lodin-Sundstrom A. Abrahamsson E. Underwater working times in two groups of traditional apnea divers in Asia: the Ama and the Bajau. Diving and Hyperbaric Medicine. 2011;41(1):27-30.) Introduction: Traditional apnea diving for sea harvesting for a living continues in some communities in Asia, the outcome being dependent on the total underwater working time. We studied dive and surface interval durations and daily time spent submerged by Japanese Ama and the Phillipine Bajau. Methods: Diving and surface interval durations were timed, and daily in-water working time noted for 14 female Ama (mean age 60 years) during sea-mollusc collection, and five male Bajau divers (mean age 38 years) during spearfishing, using direct observations and depth-time recorders. Results: In the Ama, mean (SD) dive duration was 38 (8) s, with mean surface interval duration of 38 (8) s, at depths of 5-12 metres' sea water (msw), and diving constituted 50 (4)% of the total immersed working time, which was limited to 4 h per day by fishing regulations. In the Bajau, mean dive duration was 28 (9) s, with surface intervals of 19 (8) s, at depths of 5-7 msw, and diving was 60 (6)% of the total working time. Diving patterns in Hegura-Ama were similar to those previously reported, with up to 2 h per day spent under water. The Bajau total working time of 2-9 h per day suggests that some divers may spend more than 5 h per day submerged, which is the greatest daily apnea diving time reported in humans. Conclusions: We conclude that natural human diving ability in these two groups of traditional apnea divers allows efficient sea harvesting at shallow depths and that the outcome does not seem to be limited by total daily apnea time.

  • 118.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Schagatay, Fanny Z
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Andersson, J P A
    Linér, M H
    Effects of depth and dive type on recovery of arterial oxygen saturation after deep competition apnea dives: Meeting Abstract2009In: Journal of Physiological Sciences Suppl 1, 2009, Tokyo: Springer, 2009, p. 224-224Conference paper (Refereed)
  • 119.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Nilsson, Simon
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Palm, Oscar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Lunde, Alexander
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Can the cardiorespiratory response to exercise at altitude predict sensitivity to AMS?2014Conference paper (Refereed)
  • 120.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Patrician, Alexander
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Engan, Harald
    LHL Klinikkene Roros, Roros, Norway.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Spleen Contraction and Hb Increase after Nitrate Ingestion may Explain Enhanced Apneic Diving Performance2017In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 219, no S710, p. 32-32, article id P-42Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: Ingesting nitrate-rich beetroot juice (BJ) has been suggested to enhance physical performance by reducing the oxygen cost, which could be useful in apneic diving. We previously found that after ingestion of BJ, arterial oxygen saturation was higher after static apneas (Engan et.al, Resp. Physiol & Neurobiol, 2012) and after dynamic apneas involving exercise (Patrician & Schagatay. Scand.J.Med.Sci.Sports, 2016). Our aim was to investigate the effect of BJ ingestion on spleen contraction and the resulting Hb increase, a mechanism known to prolong apneas (Schagatay et.al, J.Appl.Physiol, 2001).

    MATERIALS AND METHODS: Eight volunteers aged 24±2 years simulated diving by performing maximal apneas with face immersion during prone rest ~2.5h after ingesting 70 ml BJ (5 mmol NO3-) or placebo (0.003 mmol NO3-) on separate days in a weighted order. We measured spleen diameters for volume calculation and capillary Hb before and after "dives".

    RESULTS: Baseline (mean±SE) spleen volume was 269±33 mL with placebo and 206±27 mL after BJ ingestion (P<0.05). Post "dive" spleen volumes were smaller, but similar at 168±35 mL and 193±25 mL, respectively (NS). Baseline Hb was 145.4±3.4 g/L with placebo and 149.8±2.6 g/L with BJ (P<0.05). Post "dive" Hb had increased to 152.0±4.8 g/L with placebo and 153.7±3.0 g/L with BJ (NS). 

    CONCLUSION: With BJ ingestion spleen volume was reduced and Hb elevated even before the "dive". The elevated Hb at the start of apnea would likely have a positive effect on apneic duration by enhancing circulating oxygen stores. The positive effect of nitrate on performance in various sports could in part be due to its spleen-emptying effect, causing a natural blood boosting, which is a novel finding.

  • 121.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Haughey, Helena
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Holmberg, Hans Christer
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Naturlig bloddopning vid fysiologisk stress2004In: Svensk idrottsforskning, ISSN 1103-4629, Vol. 13, no 1, p. 18-21Article in journal (Other academic)
  • 122.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Spleen and lung volumes correlate with performance in elite apnea diversManuscript (Other academic)
  • 123.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Engan, H
    Hypercapnia augments spleen contraction and Hb increase during apnea: Meeting abstract2009In: Journal of Physiological Sciences Suppl 1, 2009, Tokyo: Springer, 2009, p. 268-268Conference paper (Refereed)
  • 124.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Richardson, Matt X.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Size matters: Spleen and lung volumes predict performance in human apneic divers2012In: Frontiers in Physiology, ISSN 1664-042X, Vol. 3, no JUN, p. Art. no. 173-Article in journal (Refereed)
    Abstract [en]

    Humans share with seals the ability to contract the spleen and increase circulating hemat-ocrit, which may improve apneic performance by enhancing gas storage. Seals have large spleens and while human spleen size is small in comparison, it shows great individual variation. Unlike many marine mammals, human divers rely to a great extent on lung oxygen stores, but the impact of lung volume on competitive apnea performance has never been determined. We studied if spleen- and lung size correlated with performance in elite apnea divers. Volunteers were 14 male apnea world championship participants, with a mean (SE) of 5.8 (1.2)years of previous apnea training. Spleen volume was calculated from spleen length, width, and thickness measured via ultrasound during rest, and vital capacity via spirometry. Accumulated competition scores from dives of maximal depth, time, and distance were compared to anthropometric measurements and training data. Mean (SE) diving performance was 75 (4) m for constant weight depth, 5 min 53 (39) s for static apnea and 139 (13) m for dynamic apnea distance. Subjects' mean height was 184 (2) cm, weight 82 (3) kg, vital capacity (VC) 7.3 (0.3) L and spleen volume 336 (32) mL. Spleen volume did not correlate with subject height or weight, but was positively correlated with competition score (r = 0.57; P< 0.05). Total competition score was also positively correlated with VC (r = 0.54; P<0.05). The three highest scoring divers had the greatest spleen volumes, averaging 538 (53) mL, while the three lowest-scoring divers had a volume of 270 (71) mL (P < 0.01). VC was also greater in the high-scorers, at 7.9 (0.36) L as compared to 6.7 (0.19) L in the low scorers (P<0.01). Spleen volume was reduced to half after 2 min of apnea in the highest scoring divers, and the estimated resting apnea time gain from the difference between high and low scorers was 15s for spleen volume and 60s forVC. We conclude that both spleen- and lung volume predict apnea performance in elite divers. © 2012 Schagatay, Richardson and Lodin-Sundström.

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  • 125.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Richardson, Matthew
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    de Bruijn, Robert
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andersson, J.
    Cardiovascular and hematological adjustments to apneic diving in humans. -Is the 'spleen-response' part of the diving response?2006In: Breath-hold diving 2006: UHMS proceedings, Orlando, USA, June 20-24, 2006, p. 20-24Conference paper (Refereed)
  • 126.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Schagatay, F
    Engan, H
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Hemoglobin concentration and performance in elite apneic divers of both genders: Meeting abstract2009In: Journal of Physiological Sciences, Suppl 1, 2009, Tokyo: Springer, 2009, p. 496-496Conference paper (Refereed)
  • 127.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schenk, C
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Dive patterns in Japanese Ama from the 2nd to the 9th decade2014Conference paper (Other academic)
  • 128.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Kampen, M
    Apneic snout immersion in trained pigs elicits a "diving response". 1995In: Advances in Experimental Medicine and Biology, ISSN 0065-2598, Vol. 393, p. 73-76Article in journal (Refereed)
  • 129.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    van Kampen, M
    Andersson, Johan
    Effects of repeated apneas on apneic time and diving response in non-divers. 1998In: Undersea and Hyperbaric Medicine, ISSN 1066-2936, no 26, p. 143-149Article in journal (Refereed)
  • 130.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    van Kampen, Marja
    Emanuelsson, Stefan
    Holm, Boris
    Effects of physical and apnea training on apneic time and diving response in humans.2000In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 82, no 3, p. 161-169Article in journal (Refereed)
    Abstract [en]

    The aim of this investigation was to study separately the effects of physical training and apnea training on the diving response and apneic time in humans. Both types of training have been suggested to lead to prolonged apneic time and an increased “diving response” (i.e., regional vasoconstriction and bradycardia). The study was also designed to examine the effects of these two types of training on the characteristics of the increase in apneic time with repeated apneas. Simulated diving tests were performed before and after the different training programs. The test format was one apnea and five apneas with facial immersion in cold water at 2-min intervals. An increase in apneic time was observed after physical training (n=24), and this was attributable to an increased time beyond the physiological breaking point. The other parameters that were measured remained unaffected. After apnea training (n=9), however, apneic time was increased by a delay in the physiological breaking point, which is mainly determined by the arterial tension of CO2. The diving response had increased, and the effect of repeated apneas on apneic time tended to be larger after apnea training. These results may explain the pronounced diving responses and long apneas observed in trained apneic divers

  • 131.
    Schagatay, Erika
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Åman, Pontus Albertsson
    Umeå University Hospital, Umeå; Country Council for Health Care, Region Norrbotten, Gällivare.
    Repeated freediving – An efficient and safe method to rescue subjects trapped in cars underwater2019In: Safety Science, ISSN 0925-7535, E-ISSN 1879-1042, Vol. 118, p. 752-756Article in journal (Refereed)
    Abstract [en]

    A method based on repeated freediving was developed to rescue subjects trapped in cars underwater – a scenario leading to 5–6 annual deaths in Sweden, and thousands globally. We determined rescue time and whether the divers were at risk of hypoxic blackout. Cars containing 5 kg negatively buoyant rescue-dummies strapped with seatbelts were placed on 5 m and 8 m depth. Eight freediving-instructors made 230 freedives, working in pairs with one diver always at the surface. For each rescue, two freedivers, equipped with mask, snorkel, fins, weight-belt, wetsuit and a buoy with belt-cutter and glass-breaker freedived alternating in turns between the divers. They accomplished a maximum of one of the following tasks per dive; (1) Finding the car; (2) Marking car with buoy; (3) Opening door/crushing window. (4) Opening/cutting belt; (5) Retrieving dummy to surface; (6) Transporting dummy to shore. Dummies were retrieved to shore from 5 m depth within a mean (SD) duration of 4 min 16 s (1 min 36 s) and from 8 m within 6 min 22 s (2 min 13 s; P &lt; 0.05). Mean dive duration was 28(7)s (14–46 s), with 3 dives over 40 s duration. Freedivers arterial oxygen saturation (SaO2) levels were measured in dives of 30, 35, 40 and 45 s using pulse oximetry. Mean (SD) SaO2 at 20 s after surfacing was 90% for 45 s dives. This allows rapid recovery and gives a safety margin to the 50% SaO2 level when divers may risk blackout. We concluded that repeated freediving is efficient for rescuing victims trapped in cars underwater within their survival time, and following recommended methods and dive durations, rescue divers are not exposed to risk. 

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  • 132. Stenfors, N
    et al.
    Hubinette, A
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Spleen contraction and erythrocyte release during exercised-induced hypoxia in patients with COPD2009In: European Respiratory Society (ERS), Vienna, Austria 12-16 Sept 2009, 2009Conference paper (Refereed)
  • 133.
    Vigetun, Helena
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Appelberg, Jonas
    Sundsvall Hospital.
    Forsberg, Tomas
    Kaldensjö, Magnus
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Diving response and Hb elevation during voluntary apnea in patients with obstructive sleep apnea.2011In: SFSS congress proceedings, 2011Conference paper (Refereed)
  • 134.
    Vigetun-Haughey, Helena
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Capio St Gorans Hosp, Dept Clin Physiol, Stockholm, Sweden.
    Appelberg, Jonas
    Sundsvall Hosp, Dept Res & Dev, Vasternorrland Cty Council, Sundsvall, Sweden.
    Forsberg, Tomas
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Kaldensjö, Magnus
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Voluntary apnea evokes diving responses in obstructive sleep apnea patients2015In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 115, no 5, p. 1029-1036Article in journal (Refereed)
    Abstract [en]

    Two potentially protective responses to apnea were studied in obstructive sleep apnea (OSA) patients; the diving response and the increase in Hb concentration [Hb] via spleen contraction. Eight OSA patients and ten healthy controls performed apneas in air (A) and apneas with facial immersion in 15 A degrees C water (FIA) after inspiration and without prior hyperventilation. In each condition, subjects performed three apneas of maximal voluntary duration spaced by 2 min of rest. Cardiorespiratory parameters were measured non-invasively, and venous blood samples for [Hb] analysis were drawn before and after apneas. Mean (SD) apnea durations were similar between groups (NS). In controls, the heart rate (HR) reduction was 10 +/- A 10 % at apnea and 19 +/- A 10 % in FIA (P < 0.05). In OSA patients, however, the fall in HR was the same in both conditions, 13 +/- A 10 and 14 +/- A 8 % for A and FIA, respectively (NS). In controls, the [Hb] increase was the same in A and FIA (2.2 +/- A 2.9 and 2.1 +/- A 2.2 %), while in OSA the [Hb] increase was greater during FIA compared to A (3.3 +/- A 2.2 and 1.4 +/- A 0.9 %; P < 0.05). Apnea induces a diving response and [Hb] increase in both groups. OSA patients did not show the typical training effect of the diving response seen in apnea divers despite their frequent nocturnal apneas. However, they also deviated from normal controls in response pattern; face immersion enhanced the cardiovascular diving response in controls but not in OSA, while the hematological response was enhanced by face immersion only in OSA patients.

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