Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance.
This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.
Kraft
Justin A
JA
Health Physical Education and Recreation, Missouri Western State University, St Joseph, Missouri, USA. jkraft@missouriwestern.edu
Green
James M
JM
Bishop
Phillip A
PA
Richardson
Mark T
MT
Neggers
Yasmin H
YH
Leeper
James D
JD
D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling / Q000502:physiology*; D004326:Drinking; D006339:Heart Rate / Q000502:physiology; D018869:Heat-Shock Response; D006400:Hematocrit; D006358:Hot Temperature; D006801:Humans; D007101:Immersion; D008297:Male; D055815:Young Adult