Kenefick, R. W., Castellani, J. W., Mahood, N. V., Hazzard, M. P., & Quinn, T. J. (2001). Thirst sensations are attenuated during exercise-cold exposure in several hydration states. Medicine and Science in Sports and Exercise, 33(5), Supplement abstract 1438.

The effects of hypohydration on thermal and thirst sensations and ratings of perceived exertion during moderate exercise in the cold were investigated. On four occasions, males (N = 8) walked while wearing t-shirts and shorts at 50% VO2max for 60 minutes in the cold (4 degrees Celsius) or in an ambient temperature of 25 degrees Celsius. Ss were dehydrated to 3-4% of body weight. On two occasions, Ss re-established normal hydration by drinking during the task. Measurements were taken every 20 minutes throughout the hour of exercise.

Skin temperature did not differ between trials. Thermal sensations were rated colder in the cold trials but were not different under each hydration state. RPE was higher in the hydrated ambient temperature condition. A diminished thirst sensation existed in the cold environment.

Since dehydration is common in the cold, a reduced thirst sensation will further increase the threat to bodily welfare unless consciously deliberate fluid intake occurs.

Implication. In cold conditions, athletes should be instructed to regularly ingest fluids irrespective of their thirst experiences.

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