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

Zurawlew, MJ, Mee, JA and Walsh, NP (2018) Heat Acclimation by Postexercise Hot-Water Immersion: Reduction of Thermal Strain During Morning and Afternoon Exercise-Heat Stress After Morning Hot-Water Immersion. International Journal of Sports Physiology and Performance, 13 (10). pp. 1281-1286. ISSN 1555-0273

Preview

Text Heat acclimation by post-exercise hot water immersion in the morning reduces thermal strain during morning and afternoon exercise-heat-stress.pdf - Accepted Version Download (672kB) | Preview

Abstract

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 degrees 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 degrees C [0.24 degrees C], PM -0.27 degrees C [0.23 degrees C]; P = .002), Tre at sweating onset (AM -0.34 degrees C [0.24 degrees C], PM -0.31 degrees C [0.25 degrees C]; P = .001), and end-exercise Tre (AM -0.47 degrees C [0.33 degrees C], PM -0.43 degrees C [0.29 degrees 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.

Item Type:	Article
Additional Information:	Accepted author manuscript version reprinted, by permission, from International Journal of Sports Physiology and Performance, 2018, 13(10): 1281-1286pp-pp, https://doi.org/10.1123/ijspp.2017-0620. © Human Kinetics, Inc.
Uncontrolled Keywords:	1106 Human Movement and Sports Sciences, 1116 Medical Physiology, 1701 Psychology
Subjects:	R Medicine > RC Internal medicine > RC1200 Sports Medicine
Divisions:	Sport and Exercise Sciences
Publisher:	Human Kinetics
Related URLs:	https://www.ncbi.nlm.nih.gov/pubmed/29745780
Date of acceptance:	4 May 2018
Date of first compliant Open Access:	16 February 2022
Date Deposited:	16 Feb 2022 09:55
Last Modified:	16 Feb 2022 10:01
DOI or ID number:	10.1123/ijspp.2017-0620
URI:	https://researchonline.ljmu.ac.uk/id/eprint/16303

View Item