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D-33 Free Communication/Poster - Heat Exposure/Exercise in the Heat Thursday, May 28, 2015, 1: 00 PM - 6: 00 PM Room: Exhibit Hall F

Water Temperature affects Perception of Thermal Comfort, but not Exertion during Immersed Cycling Exercise Tests.

1819 Board #164 May 28, 3

30 PM - 5

00 PM

McKenzie, James M.; Brammer, Christopher; Stager, Joel FACSM

Author Information
Medicine & Science in Sports & Exercise: May 2015 - Volume 47 - Issue 5S - p 495
doi: 10.1249/01.mss.0000477793.90633.9f
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PURPOSE: Exercise in the heat provides a challenge to the cardiovascular (CV) system, resulting in increased heart rate and cardiac output without a concomitant increase in workload. Subjects may feel increased discomfort due to the temperature increase, and may perceive the increase in CV factors as an increase in workload. The purpose of this study was to determine if water temperature had an effect on subject’s perception of exertion, as well as thermal comfort.

METHODS: 8 male subjects completed 3 sub-maximal cycling tests while immersed in water. The workload was set at 65% of VO2max for every trial. The water temperatures for the tests were 26.07°C, 29.71°C, and 31.47°C. Subjects were asked the Rate of Perceived Exertion (RPE) as well as Rate of Thermal Comfort (RTC) every 5 minutes during the test.

RESULTS: Subjects reported a significant increase in RTC from 6.08 ± 1.40 to 7.83 ± 0.97 (p < 0.001) from the start of exercise to the end. Differences in RTC were noted between water temperatures, as shown in the table below. RPE increased from 12.75 (±2.15) initially to 15.86 (±1.96) at the end of exercise (p<0.001), however there were no differences across water temperatures at the start (p=0.928) or end of exercise (p=0.756), despite a significantly elevated heart rate for the 31.47°C condition (p=0.036).

CONCLUSIONS: Although the water temperature did affect the subjects comfort during the immersed exercise tests, the lack of difference in RPE indicates that the subjects did not interpret that discomfort as a higher workload. It remains to be seen if further increases in water temperature or increases in exercise intensity will affect the perception of effort.

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© 2015 American College of Sports Medicine