Short-term hot water immersion results in substantial thermal strain and partial heat acclimation; comparisons with heat-exercise exposures

2021 ◽  
Vol 97 ◽  
pp. 102898
Author(s):  
Andrew M. Greenfield ◽  
Felipe Gorini Pereira ◽  
William R. Boyer ◽  
Marc R. Apkarian ◽  
Matthew R. Kuennen ◽  
...  
Keyword(s):  
Water Immersion ◽  
Thermal Strain ◽  
Heat Acclimation ◽  
Hot Water ◽  
Short Term ◽  
Hot Water Immersion

scholarly journals A comparison of heat acclimation by post-exercise hot water immersion and exercise in the heat

2021 ◽  
Author(s):  
Robert D. McIntyre ◽  
Michael J. Zurawlew ◽  
Samuel J. Oliver ◽  
Andrew T. Cox ◽  
Jessica A. Mee ◽  
...  
Keyword(s):  
Water Immersion ◽  
Heat Acclimation ◽  
Hot Water ◽  
Post Exercise ◽  
Hot Water Immersion

Seven days of hot water heat acclimation does not modulate the change in heart rate variability during passive heat exposure

2020 ◽  
Author(s):  
Philippe Gendron ◽  
Hugo Gravel ◽  
Hadiatou Barry ◽  
Daniel Gagnon
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Water Immersion ◽  
Heat Exposure ◽  
Thermal Strain ◽  
Heat Acclimation ◽  
Hot Water ◽  
Frequency Range ◽  
The Mean

We examined if the change in heart rate variability (HRV) during passive heat exposure is modified by hot water heat acclimation (HA). Sixteen healthy adults (28 ± 5 years, 5 females/11 males) underwent heat exposure in a water-perfused suit, pre and post 7 days of HA (60 minutes at rectal temperature ≥38.6°C). During passive heat exposure, heart rate (HR), the standard deviation of NN intervals (SDNN), the square root of the mean squared differences of successive NN intervals (RMSSD) and the power in the high frequency range (HF) were measured. No difference in HR (P=0.22), SDNN (P=0.87), RMSSD (P=0.79) and HF (P=0.23) was observed at baseline. The increase in HR (pre-HA: 43 ± 10, post-HA: 42 ± 9 bpm, P=0.57) and the decrease of SDNN (pre-HA: -54.1 ± 41.0, post-HA: -52.2 ± 36.8 ms, P=0.85), RMSSD (pre-HA: -70.8 ± 49.5, post-HA: -72.7 ± 50.4 ms, P=0.91) and HF (pre-HA: -28.0 ± 14.5, post-HA: -23.2 ± 17.1%, P=0.27) were not different between experimental visits at fixed increases in esophageal temperature. These results suggest that 7 consecutive days of hot water HA does not modify the change in HRV indices during passive heat exposure. Novelty bullets: - It remains unclear if heat acclimation alters the change in heart rate variability that occurs during passive heat exposure. - At matched levels of thermal strain, 7 consecutive days of hot water immersion did not modulate the change in indices of heart rate variability during passive heat exposure.

scholarly journals Substantive hemodynamic and thermal strain upon completing lower-limb hot-water immersion; comparisons with treadmill running

Temperature ◽  
2016 ◽  
Vol 3 (2) ◽  
pp. 286-297 ◽  
Author(s):  
Kate N. Thomas ◽  
André M. van Rij ◽  
Samuel J.E. Lucas ◽  
Andrew R. Gray ◽  
James D. Cotter
Keyword(s):  
Lower Limb ◽  
Water Immersion ◽  
Thermal Strain ◽  
Hot Water ◽  
Treadmill Running ◽  
Hot Water Immersion

scholarly journals Heat Acclimation by Postexercise Hot-Water Immersion: Reduction of Thermal Strain During Morning and Afternoon Exercise-Heat Stress After Morning Hot-Water Immersion

2018 ◽  
Vol 13 (10) ◽  
pp. 1281-1286 ◽  
Author(s):  
Michael J. Zurawlew ◽  
Jessica A. Mee ◽  
Neil P. Walsh
Keyword(s):  
Heat Stress ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Perceived Exertion ◽  
Water Immersion ◽  
Heat Acclimation ◽  
Time Of Day ◽  
Hot Water ◽  
Rating Of Perceived Exertion ◽  
Hot Water Immersion

Purpose: Recommendations state that to acquire the greatest benefit from heat-acclimation, the clock time of heat-acclimation sessions should match that of expected exercise-heat stress. It remains unknown if adaptations by postexercise hot-water immersion (HWI) demonstrate time-of-day-dependent adaptations. Thus, the authors examined whether adaptations following postexercise HWI completed in the morning were present during morning and afternoon exercise-heat stress. Methods: Ten males completed an exercise-heat stress test commencing in the morning (9:45 AM) and afternoon (2:45 PM; 40 min; 65% of maximal oxygen uptake treadmill run) before and after heat-acclimation. The 6-d heat-acclimation intervention involved a daily 40-min treadmill run (65% of maximal oxygen uptake) in temperate conditions followed by ≤40-min HWI (40°C; 6:30–11:00 AM). Results: Adaptations by 6-d postexercise HWI in the morning were similar in the morning and afternoon. Reductions in resting rectal temperature (Tre) (AM −0.34°C [0.24°C], PM −0.27°C [0.23°C]; P = .002), Tre at sweating onset (AM −0.34°C [0.24°C], PM −0.31°C [0.25°C]; P = .001), and end-exercise Tre (AM −0.47°C [0.33°C], PM −0.43°C [0.29°C]; P = .001), heart rate (AM −14 [7] beats·min−1, PM −13 [6] beats·min−1; P < .01), rating of perceived exertion (P = .01), and thermal sensation (P = .005) were not different in the morning compared with the afternoon. Conclusion: Morning heat acclimation by postexercise HWI induced adaptations at rest and during exercise-heat stress in the morning and midafternoon.

scholarly journals Post-exercise hot water immersion elicites heat acclimation responses in endurance and recreational athletes. A systematic review and meta-analysis

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Jack Paul Martin
Keyword(s):  
Heart Rate ◽  
Rectal Temperature ◽  
Meta Analysis ◽  
Water Immersion ◽  
Heat Acclimation ◽  
Hot Water ◽  
Design Studies ◽  
Post Exercise ◽  
Study Results ◽  
Hot Water Immersion

Aims  This meta-analysis aims to evaluate the effectiveness of heat acclimation (HA) via hot water immersion protocols and their effect on time trial (TT) performance, heart rate (HRE, HRM and HRTT), rectal temperature (Tre), Rate of perceived exertion (RPE), psychological stress index (PhSI), thermal comfort (Tcomf), thermal sensation (Tsen) and maximum oxygen uptake (Vo2max).  Methods  Pubmed, Scopus, Sportdiscus and Web of Science databases were used alongside the grey matter sites Google Scholar and Researchgate. The databases were then searched for randomised control trials and mixed-method design studies. Two RTCs, six repeated measure design studies and one randomised crossover design study were included after screening a total of 50 titles and 28 full-text articles. Sample sizes range from 1 - 13 with all participants having not participated in any form of heat training 6 months before their inclusion in the study.  Results  The mean difference (MD) for Heart rate (HR) was -9.1125 BPM (95% CI p = 0.026) and was considered to be statistically significant. The MD for Rectal temperature (Tre) effect size was -0.3814 Tre (°C) (95% CI; p = 0.05). The MD for sweat rate was 0.085; (96% CI; p = 0.0179) The changes in RPE, PhSI, Tcomf and Tsen were too small to be considered statistically significant. There was no significant difference between pre and post HA for Vo2max and PV.  This meta-analysis implies that HA via HWI may improve tolerance to discomfort during heat exposure and thus subsequently improve physical performance during exercise in hot conditions. Conclusion  The primary finding of this meta-analysis is that athletic performance is improved with post-exercise hot water immersion heat acclimation training.  HWI HA protocols should focus on the following guidelines:  40-50 minutes of submaximal exercise (>65% of Vo2max) should be followed directly (within 10 minutes) by 40 minutes of hot water immersion at 40°C with the individual immersed up to their neck.  The HA protocol should last between 6-9 days with a single bout of HWI every day for this period. 

scholarly journals Post-exercise hot water immersion elicites heat acclimation responses in endurance and recreational athletes. A systematic review and meta-analysis

2020 ◽  
Author(s):  
Jack Martin
Keyword(s):  
Heart Rate ◽  
Rectal Temperature ◽  
Meta Analysis ◽  
Water Immersion ◽  
Heat Acclimation ◽  
Hot Water ◽  
Design Studies ◽  
Post Exercise ◽  
Study Results ◽  
Hot Water Immersion

AIms This meta-analysis aims to evaluate the effectiveness of heat acclimation (HA) via hot water immersion protocols and their effect on time trial (TT) performance, heart rate (HRE, HRM and HRTT), rectal temperature (Tre), Rate of perceived exertion (RPE), psychological stress index (PhSI), thermal comfort (Tcomf), thermal sensation (Tsen) and maximum oxygen uptake (Vo2max). Methods Pubmed, Scopus, Sportdiscus and Web of Science databases were used alongside the grey matter sites Google Scholar and Researchgate. The databases were then searched for randomised control trials and mixed-method design studies. Two RTCs, six repeated measure design studies and one randomised crossover design study were included after screening a total of 50 titles and 28 full-text articles. Sample sizes range from 1 - 13 with all participants having not participated in any form of heat training 6 months before their inclusion in the study. Results The mean difference (MD) for Heart rate (HR) was -9.1125 BPM (95% CI p = 0.026) and was considered to be statistically significant. The MD for Rectal temperature (Tre) effect size was -0.3814 Tre (°C) (95% CI; p = 0.05). The MD for sweat rate was 0.085; (96% CI; p = 0.0179)The changes in RPE, PhSI, Tcomf and Tsen were too small to be considered statistically significant. There was no significant difference between pre and post HA for Vo2max and PV. This meta-analysis implies that HA via HWI may improve tolerance to discomfort during heat exposure and thus subsequently improve physical performance during exercise in hot conditions.Conclusion The primary finding of this meta-analysis is that athletic performance is improved with post-exercise hot water immersion heat acclimation training. HWI HA protocols should focus on the following guidelines: 40-50 minutes of submaximal exercise (&gt;65% of Vo2max) should be followed directly (within 10 minutes) by 40 minutes of hot water immersion at 40°C with the individual immersed up to their neck. The HA protocol should last between 6-9 days with a single bout of HWI every day for this period.

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