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Active Dehydration Impairs Upper and Lower Body Anaerobic Muscular Power

Jones, Leon C1; Cleary, Michelle A2; Lopez, Rebecca M3; Zuri, Ron E4; Lopez, Richard4

Journal of Strength & Conditioning Research:
doi: 10.1519/JSC.0b013e3181635ba5
Original Research
Abstract

We examined the effects of active dehydration by exercise in a hot, humid environment on anaerobic muscular power using a test-retest (euhydrated and dehydrated) design. Seven subjects (age, 27.1 ± 4.6 years; mass, 86.4 ± 9.5 kg) performed upper and lower body Wingate anaerobic tests prior to and after a 1.5-hour recovery from a heat stress trial of treadmill exercise in a hot, humid environment (33.1 ± 3.1oC = 55.1 ± 8.9% relative humidity) until a 3.1 ± 0.3% body mass loss was achieved. Dehydration was confirmed by a significant body mass loss (P < 0.001), urine color increase (P = 0.004), and urine specific gravity increase (P = 0.041). Motivation ratings were not significantly different (P = 0.059), and fatigue severity was significantly (P = 0.009) increased 70% in the dehydrated compared to the euhydrated condition. Compared to the euhydrated condition, the dehydrated condition mean power was significantly (P = 0.014) decreased 7.17% in the upper body and 19.20% in the lower body. Compared to the euhydrated condition, the dehydrated condition peak power was significantly (P = 0.013) decreased 14.48% in the upper body and 18.36% in the lower body. No significant differences between the euhydrated and dehydrated conditions were found for decrease in power output (P = 0.219, power = 0.213). Our findings suggest that dehydration of 2.9% body mass decreases the ability to generate upper and lower body anaerobic power. Coaches and athletes must understand that sports performance requiring anaerobic strength and power can be impaired by inadequate hydration and may contribute to increased susceptibility to musculoskeletal injury.

Author Information

1Athletics Department, Chicago State University, Chicago, Illinois; 2Department of Kinesiology and Leisure Sciences, University of Hawaii, Manoa, Honolulu, Hawaii; 3Department of Kinesiology, University of Connecticut, Storrs, Connecticut; 4Sport Science and Medicine Research Laboratory, Florida International University, Miami, Florida

Address correspondence to Michelle A. Cleary, mcleary@hawaii.edu.

© 2008 National Strength and Conditioning Association