Cardiovascular responses to head-out water immersion in Korean women breath-hold divers

The present study assessed the effects of 40 min of tail shock stress (1-s shock, 0.2 mA every 30 s) on renal and cardiovascular function in swim-trained (T), water-immersed (IM), and untrained (UT) borderline hypertensive rats (BHR). T BHR swam for 2 h/day 5 days/wk for 10–12 wk, whereas IM BHR on the same schedule were placed in water at neck level and were not permitted to swim. Age-matched sedentary controls were paired one each with the exercise group (group 1) and the immersion group (group 2). Heart rate was significantly greater in UT than in T BHR (P = 0.09) during baseline (rest). Heart rate responses during stress were not different between UT and IM BHR (group 2). Systolic and diastolic blood pressures during stress and recovery were not different between UT BHR and T or IM BHR. Urine flow rate was significantly increased from baseline during the first 20 min of stress in UT and IM BHR only. Changes in glomerular filtration rate were not consistent across studies. Renal blood flow decreased significantly from baseline during tail shock stress in UT but not T BHR. Plasma glucose levels were significantly increased above baseline during the second 20 min of stress in UT BHR only and were significantly greater than those in the T BHR. Plasma insulin levels in UT BHR were significantly decreased from baseline during tail shock stress and recovery but were unchanged from baseline in T BHR. These observations suggest that swim training independent of water immersion alters the effect that stress exerts on renal and cardiovascular function in BHR, which results in better fluid and electrolyte conservation in T BHR.

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Time course of deacclimatization to cold water immersion in Korean women divers

Journal of Applied Physiology ◽

10.1152/jappl.1983.54.6.1708 ◽

1983 ◽

Vol 54 (6) ◽

pp. 1708-1716 ◽

Cited By ~ 24

Author(s):

Y. S. Park ◽

D. W. Rennie ◽

I. S. Lee ◽

Y. D. Park ◽

K. S. Paik ◽

...

Keyword(s):

Longitudinal Study ◽

Time Course ◽

Cold Water ◽

Water Immersion ◽

Subcutaneous Fat ◽

Seasonal Fluctuation ◽

Cold Water Immersion ◽

Korean Women ◽

Subcutaneous Fat Thickness ◽

Fat Thickness

Seasonal basal metabolic rates (BMR), critical water temperature (Tcw), maximal body insulations (Imax), and finger blood flow during hand immersion in 6 degrees C water (Q finger) were measured periodically during the course of a 3-yr longitudinal study (1980–1982) of modern Korean diving women (ama), who have been wearing wet suits since 1977 to avoid cold stress during work. Methods and protocols were identical to previous studies of cotton-suited ama from 1961–1974. The BMR of modern ama did not undergo seasonal fluctuation (1980–1981) and was within the DuBois standard and comparable to nondivers year around Tcw of ama was still reduced by 2–3 degrees C in 1980 but increased progressively to equal that of nondivers in 1982, when compared at comparable subcutaneous fat thickness (SFT). Since modern ama and nondivers have 2.4 times thicker SFT (i.e., 4–13 mm) than in 1962 the absolute Tcw is significantly reduced. Q finger of ama was also significantly lower than controls in 1980 but in 1981–1982 was identical to controls. Imax of modern ama was identical to controls of comparable SFT in 1980–1982. The time course of cold deacclimatization thus was BMR, 3 yr; Imax, 3 yr; Q finger, 4 yr; and Tcw, 5 yr. This longitudinal study provides further evidence that acclimatization to cold did at one time exist in these diving women.

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Breath-Hold Time During Cold Water Immersion: Effects of Habituation with Psychological Training

Aviation Space and Environmental Medicine ◽

10.3357/asem.2100.2007 ◽

2007 ◽

Vol 78 (11) ◽

pp. 1029-1034 ◽

Cited By ~ 12

Author(s):

Martin J. Barwood ◽

Avijit K. Datta ◽

Richard C. Thelwell ◽

Michael J. Tipton

Keyword(s):

Cold Water ◽

Water Immersion ◽

Hold Time ◽

Cold Water Immersion ◽

Breath Hold ◽

Psychological Training

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Blood Gas Analyses in Hyperbaric and Underwater Environments: A Systematic Review

Journal of Applied Physiology ◽

10.1152/japplphysiol.00569.2021 ◽

2021 ◽

Author(s):

Matteo Paganini ◽

Richard E. Moon ◽

Nicole Boccalon ◽

Giorgio E.M. Melloni ◽

Tommaso Antonio Giacon ◽

...

Keyword(s):

Water Immersion ◽

Correlation Coefficients ◽

Blood Gases ◽

Breath Hold ◽

Blood Gas ◽

Arterial Blood ◽

Gas Measurement ◽

Hyperbaric Environment ◽

Blood Gas Analyses ◽

Hyperbaric Conditions

Background: Pulmonary gas exchange during diving or in a dry hyperbaric environment is affected by increased breathing gas density and possibly water immersion. During free diving there is also the effect of apnea. Few studies have published blood gas data in underwater or hyperbaric environments: this review summarizes the available literature and was used to test the hypothesis that arterial PO2 under hyperbaric conditions can be predicted from blood gas measurement at 1 atmosphere assuming a constant arterial/alveolar PO2 ratio (a:A). Methods: A systematic search was performed on traditional sources including arterial blood gases obtained on humans in hyperbaric or underwater environments. The a:A was calculated at 1 atmosphere absolute (ATA). For each condition, predicted PaO2 at pressure was calculated using the 1 ATA a:A, and the measured PaO2 was plotted against the predicted value with Spearman correlation coefficients. Results: Of 3640 records reviewed, 30 studies were included: 25 were reports describing values obtained in hyperbaric chambers, and the remaining were collected while underwater. Increased inspired O2 at pressure resulted in increased PaO2, although underlying lung disease in patients treated with hyperbaric oxygen attenuated the rise. PaCO2 generally increased only slightly. In breath-hold divers, hyperoxemia generally occurred at maximum depth, with hypoxemia after surfacing. The a:A adequately predicted the PaO2 under various conditions: dry (r=0.993, p< 0.0001); rest vs. exercise (r=0.999, p< 0.0001); and breathing mixtures (r=0.995, p< 0.0001). Conclusion: Pulmonary oxygenation under hyperbaric conditions can be reliably and accurately predicted from 1 ATA a:A measurements.

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Erythropoietic responses to a series of repeated maximal dynamic and static apnoeas in elite and non-breath-hold divers

European Journal of Applied Physiology ◽

10.1007/s00421-019-04235-1 ◽

2019 ◽

Vol 119 (11-12) ◽

pp. 2557-2565 ◽

Cited By ~ 2

Author(s):

Antonis Elia ◽

Matthew J. Barlow ◽

Kevin Deighton ◽

Oliver J. Wilson ◽

John P. O’Hara

Keyword(s):

Water Immersion ◽

Significant Negative Correlation ◽

Group Differences ◽

Breath Hold ◽

The Novel ◽

Peripheral Oxygen Saturation ◽

Blood Samples ◽

And Control ◽

Maximal Effort ◽

Serum Erythropoietin

Abstract Purpose Serum erythropoietin (EPO) concentration is increased following static apnoea-induced hypoxia. However, the acute erythropoietic responses to a series of dynamic apnoeas in non-divers (ND) or elite breath-hold divers (EBHD) are unknown. Methods Participants were stratified into EBHD (n = 8), ND (n = 10) and control (n = 8) groups. On two separate occasions, EBHD and ND performed a series of five maximal dynamic apnoeas (DYN) or two sets of five maximal static apnoeas (STA). Control performed a static eupnoeic (STE) protocol to control against any effects of water immersion and diurnal variation on EPO. Peripheral oxygen saturation (SpO2) levels were monitored up to 30 s post each maximal effort. Blood samples were collected at 30, 90, and 180 min after each protocol for EPO, haemoglobin and haematocrit concentrations. Results No between group differences were observed at baseline (p > 0.05). For EBHD and ND, mean end-apnoea SpO2 was lower in DYN (EBHD, 62 ± 10%, p = 0.024; ND, 85 ± 6%; p = 0.020) than STA (EBHD, 76 ± 7%; ND, 96 ± 1%) and control (98 ± 1%) protocols. EBHD attained lower end-apnoeic SpO2 during DYN and STA than ND (p < 0.001). Serum EPO increased from baseline following the DYN protocol in EBHD only (EBHD, p < 0.001; ND, p = 0.622). EBHD EPO increased from baseline (6.85 ± 0.9mlU/mL) by 60% at 30 min (10.82 ± 2.5mlU/mL, p = 0.017) and 63% at 180 min (10.87 ± 2.1mlU/mL, p = 0.024). Serum EPO did not change after the STA (EBHD, p = 0.534; ND, p = 0.850) and STE (p = 0.056) protocols. There was a significant negative correlation (r = − 0.49, p = 0.003) between end-apnoeic SpO2 and peak post-apnoeic serum EPO concentrations. Conclusions The novel findings demonstrate that circulating EPO is only increased after DYN in EBHD. This may relate to the greater hypoxemia achieved by EBHD during the DYN.

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