BASSETT, JR., D. R., F. J. NAGLE, S. MOOKERJEE, K. C. DARR, A. V. NG, S. G. VOSS, and J. P. NAPP. Thermoregulatory responses to skin wetting during prolonged treadmill running. Med. Sci. Sports Exerc., Vol. 19, No. 1, pp. 28-32, 1987. We examined the physiological responses to skin wetting during a 120-min level treadmill run to assess whether skin wetting would reduce the dehydration and the increase in core temperature associated with prolonged exercise. Testing was conducted in an environmental chamber (T = 29.5[degrees]C, wind velocity = 3 m[middle dot]sec-1) under two different humidity conditions (33 or 66% relative humidity). Ten male subjects performed two runs in each humidity condition; one served as a control run. The other included spraying the body with 50 ml of water (T = 29.5[degrees]C) every 10 min. Spraying had no effect on rectal temperature (Tre), heart rate, oxygen consumption, perceived exertion, sweat loss, or percent change in plasma volume in both the humid and the dry conditions. Spraying produced a significant reduction in mean skin temperature ([Latin capital letter T with macron accent]sk), which increased the (Tre - [Latin capital letter T with macron accent]sk) gradient. At the same time, overall skin conductance (K) was decreased, presumably as a result of cutaneous vasoconstriction due to the low [Latin capital letter T with macron accent]sk. Since heat transfer from the body's core to the skin is expressed by the equation:
heat transfer = K x (Tre - [Latin capital letter T with macron accent]sk)
the spraying had no effect on heat transfer away from the core, and Tre remained unchanged.
(C)1987The American College of Sports Medicine