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  • 1.
    Barlow, Matthew J.
    et al.
    Leeds Beckett Univ, Inst Sport Phys Act & Leisure, Leeds, Yorkshire, England.
    Elia, Antonis
    Leeds Beckett Univ, Inst Sport Phys Act & Leisure, Leeds, Yorkshire, England.
    Shannon, Oliver M.
    Leeds Beckett Univ, Inst Sport Phys Act & Leisure, Leeds, Yorkshire, England.
    Zacharogianni, Angeliki
    Leeds Beckett Univ, Inst Sport Phys Act & Leisure, Leeds, Yorkshire, England.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The Effect of a Dietary Nitrate Supplementation in the Form of a Single Shot of Beetroot Juice on Static and Dynamic Apnea Performance2018In: International Journal of Sport Nutrition & Exercise Metabolism, ISSN 1526-484X, E-ISSN 1543-2742, Vol. 28, no 5, p. 497-501Article in journal (Refereed)
    Abstract [en]

    The purpose of the present study was to assess the effects of acute nitrate (NO3-)-rich beetroot juice (BRJ) supplementation on peripheral oxygen saturation (SpO(2)), heart rate (HR), and pulmonary gas exchange during submaximal static and dynamic apnea. Methods: Nine (six males and three females) trained apneists (age: 39.6 +/- 8.2 years, stature: 170.4 +/- 11.5 cm, and body mass: 72.0 +/- 11.5 kg) performed three submaximal static apneas at 60%, 70%, and 80% of the participant's current reported personal best time, followed by three submaximal (similar to 75% or personal best distance) dynamic apneas following the consumption of either a 70-ml concentrated BRJ (7.7 mmol NO3-) or a NO3--depleted placebo (PLA; 0.1 mmol NO3-) in doubleblind randomized manner. HR and SpO(2) were measured via fingertip pulse oximetry at the nadir, and online gas analysis was used to assess pulmonary oxygen uptake ((V)over dotO2) during recovery following breath-holds. Results: There were no differences (p < .05) among conditions for HR (PLA = 59 +/- 11 bpm and BRJ = 61 +/- 12 bpm), SpO(2) (PLA = 83% +/- 14% and BRJ = 84% +/- 9%), or (V)over dotO2 (PLA = 1.00 +/- 0.22 L/min and BRJ = 0.97 +/- 0.27 L/min). Conclusion: The consumption of 7.7 mmol of beetroot juice supplementation prior to a series of submaximal static and dynamic apneas did not induce a significant change in SpO(2), HR, and (V)over dotO2 when compared with placebo. Therefore, there is no apparent physiological response that may benefit free divers as a result of the supplementation.

  • 2.
    Engan, Harald K.
    et al.
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Comparison of two methods potentially reducing metabolism during apnea2015Conference paper (Refereed)
  • 3.
    Engan, Harald K.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. LHL Health Röros, Norwegian Heart and Lung Patient Organization, Oslo, Norway.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Schagatay, Fanny
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The effect of climbing mount everest on spleen contraction and increase in hemoglobin concentration during breath holding and exercise2014In: High Altitude Medicine & Biology, ISSN 1527-0297, E-ISSN 1557-8682, Vol. 15, no 1, p. 52-57Article in journal (Refereed)
    Abstract [en]

    Release of stored red blood cells resulting from spleen contraction improves human performance in various hypoxic situations. This study determined spleen volume resulting from two contraction-evoking stimuli: breath holding and exercise before and after altitude acclimatization during a Mount Everest ascent (8848m). Eight climbers performed the following protocol before and after the climb: 5min ambient air respiration at 1370m during rest, 20min oxygen respiration, 20min ambient air respiration at 1370m, three maximal-effort breath holds spaced by 2min, 10min ambient air respiration, 5min of cycling at 100 W, and finally 10min ambient air respiration. We measured spleen volume by ultrasound and capillary hemoglobin (HB) concentration after each exposure, and heart rate (HR) and arterial oxygen saturation (Sao2) continuously. Mean (SD) baseline spleen volume was unchanged at 213 (101) mL before and 206 (52) mL after the climb. Before the climb, spleen volume was reduced to 184 (83) mL after three breath holds, and after the climb three breath holds resulted in a spleen volume of 132 (26) mL (p=0.032). After exercise, the preclimb spleen volume was 186 (89) mL vs. 112 (389) mL) after the climb (p=0.003). Breath hold duration and cardiovascular responses were unchanged after the climb. We concluded that spleen contraction may be enhanced by altitude acclimatization, probably reflecting both the acclimatization to chronic hypoxic exposure and acute hypoxia during physical work. © Copyright 2014, Mary Ann Liebert, Inc. 2014.

  • 4.
    Engan, Harald
    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, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Blood lactate after deep dives in 3 disciplines of competitive apnea2010In: Proceedings from the European Underwater Baromedical Society 36th Annual Meeting Istanbul, Turkey 14-18 Sept 2010, 2010Conference paper (Refereed)
  • 5.
    Engan, Harald
    et al.
    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.
    Schagatay, Fanny
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Enhanced blood boosting spleen contraction after climbing Mt Everest2014Conference paper (Refereed)
  • 6.
    Engan, Harald
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. Department of Human Movement Science, Faculty of Social Sciences and Technology Management, NTNU, Trondheim, Norway.
    Schagatay, Erika
    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.
    Richardson, Matt
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Beekvelt, Mireille
    Department of Human Movement Science, Faculty of Social Sciences and Technology Management, NTNU, Trondheim, Norway.
    Effects of two weeks of daily apnea training on diving response, spleen contraction, and erythropoiesis in novel subjects.2013In: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 23, no 3, p. 340-348Article in journal (Refereed)
    Abstract [en]

    Three potentially protective responses to hypoxia have been reported to be enhanced in divers: (1) the diving response, (2) the blood-boosting spleen contraction, and (3) a long-term enhancement of hemoglobin concentration (Hb). Longitudinal studies, however, have been lacking except concerning the diving response. Ten untrained subjects followed a 2-week training program with 10 maximal effort apneas per day, with pre- and posttraining measurements during three maximal duration apneas, and an additional post-training series when the apneic duration was kept identical to that before training. Cardiorespiratory parameters and venous blood samples were collected across tests, and spleen diameters were measured via ultrasound imaging. Maximal apneic duration increased by 44 s (P < 0.05). Diving bradycardia developed 3 s earlier and was more pronounced after training (P < 0.05). Spleen contraction during apneas was similar during all tests. The arterial hemoglobin desaturation (SaO(2)) nadir after apnea was 84% pretraining and 89% after the duration-mimicked apneas post-training (P < 0.05), while it was 72% (P < 0.05) after maximal apneas post-training. Baseline Hb remained unchanged after training, but reticulocyte count increased by 15% (P < 0.05). We concluded that the attenuated SaO(2) decrease during mimic apneas was due mainly to the earlier and more pronounced diving bradycardia, as no enhancement of spleen contraction or Hb had occurred. Increased reticulocyte count suggests augmented erythropoiesis.

  • 7. Fernández, FA
    et al.
    Patrician, Alexander
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Predicting static and dynamic apnea performance in elite divers using a 2-minute static apnea test2015Conference paper (Refereed)
  • 8.
    Havnes, Marianne B
    et al.
    NTNU, Trondheim Norway.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Rasdal, Kim Vidar
    NTNU, Trondheim Norway.
    Brubakk, Alf O
    NTNU, Trondheim Norway.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Bubbles after deep breath-hold dives in competition2010In: Proceedings from the European Underwater Baromedical Society 36th Annual Meeting Istanbul, Turkey 14-18 Sept 2010, 2010Conference paper (Refereed)
  • 9.
    Holmström, Pontus
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Mulder, Eric
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Nursing Sciences.
    Limbu, Prakash
    Nepalese Army Inst Hlth Sci, Kathmandu, Nepal.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The Magnitude of Diving Bradycardia During Apnea at Low-Altitude Reveals Tolerance to High Altitude Hypoxia2019In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 10, p. 1-12, article id 1075Article in journal (Refereed)
    Abstract [en]

    Acute mountain sickness (AMS) is a potentially life-threatening illness that may develop during exposure to hypoxia at high altitude (HA). Susceptibility to AMS is highly individual, and the ability to predict it is limited. Apneic diving also induces hypoxia, and we aimed to investigate whether protective physiological responses, i.e., the cardiovascular diving response and spleen contraction, induced during apnea at low-altitude could predict individual susceptibility to AMS. Eighteen participants (eight females) performed three static apneas in air, the first at a fixed limit of 60 s (A1) and two of maximal duration (A2-A3), spaced by 2 min, while SaO(2), heart rate (HR) and spleen volume were measured continuously. Tests were conducted in Kathmandu (1470 m) before a 14 day trek to mount Everest Base Camp (5360 m). During the trek, participants reported AMS symptoms daily using the Lake Louise Questionnaire (LLQ). The apnea-induced HR-reduction (diving bradycardia) was negatively correlated with the accumulated LLQ score in A1 (r(s) = -0.628, p= 0.005) and A3 (r(s) = -0.488, p = 0.040) and positively correlated with SaO(2) at 4410 m (A1: r = 0.655, p = 0.003; A2: r = 0.471, p = 0.049; A3: r = 0.635, p = 0.005). Baseline spleen volume correlated negatively with LLQ score (r(s) = -0.479, p = 0.044), but no correlation was found between apnea-induced spleen volume reduction with LLQ score (r(s) = 0.350, p = 0.155). The association between the diving bradycardia and spleen size with AMS symptoms suggests links between physiological responses to HA and apnea. Measuring individual responses to apnea at sea-level could provide means to predict AMS susceptibility prior to ascent.

  • 10.
    Johansson, Hampus
    et al.
    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.
    Melin, Maja
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Patrician, Alexander
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    No effect of dietary nitrate on the human diving response in dry and wet apneas2015Conference paper (Refereed)
  • 11.
    Lodin, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Initiation of spleen contraction resulting in natural blood boosting in humans2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The spleen has been shown to contract in apneic situations in humans as well as in other diving mammals, expelling its stored red blood cell content into circulation. This natural blood boosting may increase the circulating hemoglobin concentration (Hb) by up to 10%, which would enhance the oxygen carrying capacity and likely increase performance. However, the triggers of this response in humans have not been fully clarified. Study I was therefore focused on the effect of hypoxia as a trigger of spleen contraction. It was found that 20 min of normobaric hypoxic breathing evoked a substantial reduction in spleen volume showing that hypoxia is an important trigger for spleen contraction. Knowing the role of hypoxia, Study II compared two different hypoxic situations – a 2 min apnea and 20 min normobaric hypoxic breathing – which resulted in the same level of arterial hemoglobin desaturation. Apnea evoked a twice as great spleen volume reduction, implying that variables other than hypoxia were likely involved in triggering spleen contraction. This may be hypercapnia which is present during apnea but not during normobaric hypoxic breathing. Study III therefore investigated the effects of breathing gas mixtures containing different proportions of CO2 prior to maximal apneas. Pre-breathing mixtures with higher percentages of CO2 resulted in greater spleen contraction, thus demonstrating hypercapnia's likely role as a trigger in addition to hypoxia. Study IV explored whether an all-or-nothing threshold stimulus for triggering spleen contraction existed, or if contraction was graded in relation to the magnitude of triggering stimuli. Exercise was therefore performed in an already hypoxic state during normobaria. Rest in hypoxia produced a moderate spleen volume reduction, with an enhanced spleen contraction resulting after hypoxic exercise, with a concomitant increase in Hb. This implies that spleen contraction is a graded response related to the magnitude of the stimuli. This could be beneficial in environments with varying oxygen content or work loads. Study V examined the possibility that spleen contraction is part of the acclimatization to altitude, during an expedition to summit Mt Everest. The long-term high altitude exposure, combined with physical work on the mountain, had no effects on resting spleen volume but resulted in a stronger spleen contraction, when provoked by apnea or exercise. This indicates that acclimatization to altitude may enhance the contractile capacity of the spleen, which may be beneficial for the climber. From these studies I concluded that hypoxia is an important trigger for spleen contraction but that hypercapnia also contributes in apneic situations. The spleen contraction likely provides a graded expulsion of erythrocytes in response to these stimuli, causing a temporary increase in gas storage capacity that may facilitate activities such as freediving and climbing. The storage of erythrocytes during rest serves to reduce blood viscosity, which would also be beneficial for the climber or diver. The human spleen contraction appears to become stronger with acclimatization, with beneficial effects at altitude. Such an upgraded response could be beneficial both in sports and diseases involving hypoxia.

  • 12. Lodin-Sundström, Angelica
    et al.
    Engan, H
    Richarson, Matt
    Schagatay, Erika
    Oxygen conservation by the diving response improved after 2 weeks of apnea training2009In: 14th Annual Congress of the ECSS in Oslo, Norway 24-27 June 2009, 2009Conference paper (Refereed)
  • 13.
    Lodin-Sundström, Angelica
    et al.
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Mechanisms underlying spleen contraction during apneic diving2015Conference paper (Refereed)
  • 14.
    Lodin-Sundström, Angelica
    et al.
    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.
    Schagatay, Fanny
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Effects of warm-up on static apnea performance2010In: Proceedings from the European Underwater Baromedical Society 36th Annual Meeting Istanbul, Turkey 14-18 Sept 2010, 2010Conference paper (Refereed)
  • 15.
    Lodin-Sundström, Angelica
    et al.
    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.
    Palm, Oscar
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Nilsson, Simon
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Swedish Winter Sports Research Centre, Östersund, Sweden..
    Blood boosting by spleen contraction during exercise at different altitudes.2014Conference paper (Refereed)
    Abstract [en]

    Spleen contraction with release of erythrocytes improves human performance in hypoxic situations. Hypoxia and exercise are known to separately trigger the response. We studied the response to exercise at different altitudes during a two week ascent to 4200m. Eleven healthy lowlanders (five women; mean±SD age 26±3 years) did a modified Harvard step test at 1370, 3700 and 4200m altitude after 10 min rest. Spleen volume was measured via ultrasonic imaging and capillary hemoglobin (Hb) with Hemocue before and after tests. Mean(±SD) baseline spleen volume at 1370m was 250(±9)ml, after exercise it had been reduced to 207(±10)ml (P<0.01). At 3700m, baseline spleen volume was 230(±9)ml, after exercise 173(±10)ml (P<0.01). At 4200m baseline was 211(±10)ml, after exercise 158(±13)ml (P<0.05). Baseline Hb increased by altitude from 137.8(±3.8)g/L at 1370m, to 141.2(±2.3)g/L at 3700m and 151.4(±2.3)g/L at 4200m (P<0.01). At all locations Hb had increased after exercise; at 1370m by 7.2%, at 3700m by 6.2% and at 4200m by 3.2%. This suggests the spleen was already somewhat contracted during rest at higher altitudes, which was reflected by the progressively higher baseline Hb. Exercise initiated spleen contraction of similar magnitude at all altitudes, and post exercise values were progressively smaller with altitude. Hb was also elevated at all exercise tests, but not directly reflecting the spleen volume reductions, possibly due to differences in peak times. This study suggests that baseline spleen volume is affected by altitude which elevates Hb and that contraction after exercise results in further Hb elevation.

  • 16.
    Lodin-Sundström, Angelica
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Biphasic spleen contraction during apnea in divers suggests chemoreceptor input2009In: Abstract EUBS Aberdeen, UK, 25-28 Aug, 2009., 2009Conference paper (Refereed)
  • 17.
    Lodin-Sundström, Angelica
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Spleen contraction and erythrocyte release in elite apnea divers during submaximal and maximal effort apneas2009In: 14th Annual Congress of the ECSS in Oslo, Norway 24-27 June 2009, 2009Conference paper (Refereed)
  • 18.
    Lodin-Sundström, Angelica
    et al.
    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 develops progressively across long apneas: Meeting abstract2009In: Journal of Physiological Sciences, Suppl 1, 2009, Tokyo: Springer, 2009, p. 504-504Conference paper (Refereed)
  • 19.
    Lodin-Sundström, Angelica
    et al.
    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 during 20 min normobaric hypoxia and 2 min apnea in humans2010In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 81, no 6, p. 545-549Article in journal (Refereed)
    Abstract [en]

    Introduction: Spleen contraction occurs in humans during exercise, apnea, and simulated altitude, resulting in ejection of stored red blood cells into circulation. The mechanisms responsible for initiating the contraction are not fully known: hypoxia is likely involved, but other, unknown factors may also contribute. To reveal the initiating factors, we studied its occurrence in two different situations involving similar reductions in arterial oxygen saturation (SaO2). We hypothesized that similar spleen responses would result if the level of hypoxia is the main factor involved. Methods: Five female and four male healthy volunteers performed two different trials on separate days: 1)20 min of normobaric hypoxic breathing (14.2% oxygen); and II) 2 min of apnea after a deep inspiration of air. Both trials started and ended with 10 min of sitting eupneic rest. Spleen diameter was intermittently measured via ultrasonic imaging in three dimensions to calculate volume. S aO2 and heart rate (HR) were recorded continuously with a pulse oximeter. Results: Exposures resulted in similar nadir SaO 2: 87% after normobaric hypoxia and 89% after apnea. During normobaric hypoxia, spleen volume was reduced by 16% and during apnea by 34%. HR increased by 7% during normobaric hypoxia, but fell by 25% during apnea. Discussion: Both normobaric hypoxia and apnea induced spleen contraction, but despite similar levels of SaO2 apnea evoked a significantly stronger response, possibly due to hypercapnia, faster desaturation, ortheapneic stimulus in itself. Spleen contraction may facilitate adaptation to altitude and to apneic diving by elevating blood gas storage capacity.

  • 20.
    Lodin-Sundström, Angelica
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Söderberg, Daniel
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Ekstam, Marcus
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences. Swedish Winter Sports Research Centre, Östersund, Sweden..
    Exercise at simulated altitude enhances spleen contraction2014Conference paper (Refereed)
  • 21.
    Melin, Maja
    et al.
    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.
    Johansson, Hampus
    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 K.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The effect of dietary nitrate on spleen contraction and Hb increase during apnea2015Conference paper (Refereed)
  • 22.
    Patrician, Alexander
    et al.
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Johansson, Hampus
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Melin, Maja
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    The effect of dietary nitrate on spleen contraction and diving response during apnea2015Conference paper (Refereed)
  • 23.
    Richardson, Matt
    et al.
    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.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Effect of hypercapnia on spleen-related haemoglobin increase during apnea2012In: Diving and Hyperbaric Medicine, ISSN 1833-3516, Vol. 42, no 1, p. 4-9Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:

    Splenic contraction associated with apnea causes increased haemoglobin concentration and haematocrit (Hct), an effect that may promote prolonged breath-holding. Hypoxia has been shown to augment this effect, but hypercapnic influences have not been investigated previously.

    METHODS:

    Eight non-divers performed three series of apneas on separate days after inspiration of oxygen with different carbon dioxide (CO₂) levels. Each series consisted of three apneas 2 minutes apart: one with pre-breathing of 5% CO₂ in oxygen (O₂, 'Hypercapnia'); one with pre-breathing of 100% O₂ ('Normocapnia'); and one with hyperventilation of 100% O₂ ('Hypocapnia'). The apnea durations were repeated identically in all trials, determined from the maximum duration attained in the CO₂ trial. A fourth trial, breathing 5% CO₂ in O₂ for the same duration as these apneas was also performed ('Eupneic hypercapnia'). In three subjects, spleen size was measured using ultrasonic imaging.

    RESULTS:

    Haemoglobin increased by 4% after apneas in the 'Hypercapnia' trial (P = 0.002) and by 3% in the 'Normocapnia' trial (P = 0.011), while the 'Hypocapnia' and 'Eupneic hypercapnia' trials showed no changes. The 'easy' phase of apnea, i.e., the period without involuntary breathing movements, was longest in the 'Hypocapnia' trial and shortest in the 'Hypercapnia' trial. A decrease in spleen size was evident in the hypercapnic trial, whereas in the hypocapnia trial spleen size increased, while only minor changes occurred in the other trials. No differences were observed between trials in the cardiovascular diving response.

    CONCLUSION:

    There appears to be a dose-response effect of CO₂ on triggering splenic contraction during apnea in the absence of hypoxia.

  • 24.
    Richardson, Matt
    et al.
    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.
    Engan, Harald
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Hypercapnia moderates hemoglobin increases during apneaManuscript (Other academic)
  • 25.
    Richardson, Matt
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lodin, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Reimers, J
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Short-term effects of normobaric hypoxia on the human spleen2008In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 104, no 2, p. 395-399Article in journal (Refereed)
    Abstract [en]

    Spleen contraction resulting in an increase in circulating erythrocytes has been shown to occur during apnea. This effect, however, has not previously been studied during normobaric hypoxia whilst breathing. After 20 min of horizontal rest and normoxic breathing, five subjects underwent 20-min of normobaric hypoxic breathing (12.8% oxygen) followed by 10 min of normoxic breathing. Ultrasound measurements of spleen volume and samples for venous hemoglobin concentration (Hb) and hematocrit (Hct) were taken simultaneously at short intervals from 20 min before until 10 min after the hypoxic period. Heart rate, arterial oxygen saturation (SaO2) and respiration rate were recorded continuously. During hypoxia, a reduction in SaO2 by 34% (P < 0.01) was accompanied by an 18% reduction in spleen volume and a 2.1% increase in both Hb and Hct (P < 0.05). Heart rate increased 28% above baseline (P < 0.05). Within 3 min after hypoxia SaO2 had returned to pre-hypoxic levels, and spleen volume, Hb and Hct had all returned to pre-hypoxic levels within 10 min. Respiratory rate remained stable throughout the protocol. This study of short-term exposure to eupneic normobaric hypoxia suggests that hypoxia plays a key role in triggering spleen contraction and subsequent release of stored erythrocytes in humans. This response could be beneficial during early altitude acclimatization.

  • 26.
    Richardson, Matt
    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, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    Spleen contraction in accessory spleens during apnea in elite divers2009In: Abstract EUBS Aberdeen, UK, 25-28 Aug, 2009, 2009Conference paper (Refereed)
  • 27.
    Rodríguez-Zamora, Lara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain..
    Engan, Harald K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. LHL Health Röros, The Norwegian Heart and Lung Patient Organization, Norway..
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Iglesias, Xavier
    Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain.
    Rodríguez, Ferran A
    Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. Swedish Winter Sports Research Centre, Östersund, Sweden..
    Blood lactate after competitive free diving and synchronized swimming events2013Conference paper (Refereed)
  • 28.
    Rodríguez-Zamora, Lara
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain..
    Engan, Harald K
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering. LHL Health Röros, The Norwegian Heart and Lung Patient Organization, Norway..
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Iglesias, Xavier
    Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain.
    Rodríguez, Ferran A
    Institut Nacional d’Educació Física de Catalunya, Universitat de Barcelona, Barcelona, Spain.
    Schagatay, Erika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Blood lactate after competitive free diving and synchronized swimming eventsManuscript (preprint) (Other academic)
  • 29.
    Rodríguez-Zamora, Lara
    et al.
    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. Norwegian Heart & Lung Patient Org, Norway.
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schagatay, Fanny
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Iglesias, Xavier
    Univ Barcelona, INEFC Barcelona Sports Sci Res Grp, Barcelona, Spain.
    Rodriguez, Ferran A.
    Univ Barcelona, INEFC Barcelona Sports Sci Res Grp, Barcelona, Spain.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Blood lactate accumulation during competitive freediving and synchronized swimming2018In: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 45, no 1, p. 55-63Article in journal (Refereed)
    Abstract [en]

    A number of competitive water sports are performed while breath-holding (apnea). Such performances put large demands on the anaerobic system, but the study of lactate accumulation in apneic sports is limited. We therefore aimed to determine and compare the net lactate accumulation (NLA) during competition events in six disciplines of competitive freediving (FD) and three disciplines of synchronized swimming (SSW). The FD disciplines were: static apnea (STA; n = 14) dynamic apnea (DYN; n = 19) dynamic apnea no fins (DNF; n = 16) constant weight (CWT; n = 12) constant weight no fins (CNF; n = 8) free immersion (FIM; n =10) The SSW disciplines were solo (n = 21), duet (n = 31) and team (n = 34). Capillary blood lactate concentration was measured before and three minutes after competition performances, and apneic duration and performance variables were recorded. In all nine disciplines NLA was observed. The highest mean (SD) NLA (mmol.L-1) was found in CNF at 6.3 (2.2), followed by CWT at 5.9 (2.3) and SSW solo at 5 (1.9). STA showed the lowest NLA 0.7 (0.7) mmol.L-1 compared to all other disciplines (P < 0.001). The NLA recorded shows that sports involving apnea involve high levels of anaerobic activity. The highest NLA was related to both work done by large muscle groups and long apneic periods, suggesting that NLA is influenced by both the type of work and apnea duration, with lower NLA in SSW due to shorter apneic episodes with intermittent breathing.

  • 30.
    Rodríguez-Zamora, Lara
    et al.
    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.
    Höök, Martina
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Patrician, Alexander
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Degerström, E
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Effects of altitude acclimatization on spleen volume and contraction during submaximal and maximal work in lowlanders2015Conference paper (Refereed)
  • 31.
    Rodríguez-Zamora, Lara
    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.
    Starfelt, Victor
    Olander, Carl
    Lodin-Sundström, Angelica
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Schagatay, Erika
    Mid Sweden University, Faculty of Human Sciences, Department of Health Sciences.
    Physiological responses to apnea at sea level predict SaO2 at simulated 5300 m altitude2016Conference paper (Refereed)
  • 32.
    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)
  • 33.
    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.
    Stenfors, Nikolai
    Department of Public Health and Clinical Medicine, Unit of Research, Education and Development - ÖstersundUmeå UniversityUmeåSweden.
    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.

  • 34.
    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)
  • 35.
    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.

  • 36.
    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)
  • 37.
    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.

  • 38.
    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)
  • 39.
    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.

  • 40.
    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)
  • 41.
    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)
  • 42.
    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.

  • 43.
    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)
  • 44.
    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)
  • 45.
    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.

  • 46.
    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)
  • 47.
    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)
  • 48. 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)
1 - 48 of 48
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