LOWER BODY VS. WHOLE BODY PRECOOLING
I n t h e p r e s e n t s t u d y , m e a n T b w a s e s t i m a t e d b y t h e B u r t o n e q u a t i o n ( 5 ) , w h e r e i n T r e i s g i v e n t h e w e i g h t factor of 0.65, and mean Tsk is given the weighting factor of 0.35. The Burton equation was used because of the higher weighting of Tsk, because during a cold stress, especially during water immersion, skin tem- perature is more important in thermal balance. Al- though other weighting systems (e.g., 0.8 Tre and 0.2 mean Tsk or 0.9 Tre and 0.1 mean Tsk) used in the literature slightly alter the calculated mean Tb value, using them would not affect the interpretation of the data comparing the two treatments. i n g
Water immersion to the level of the neck alters body fluid balance and cardiovascular responses while in the water (9). However, we did not observe the character- istic baroreceptor-mediated decrease in heart rate due to increases in central blood volume during water im- mersion to the level of the neck because of the overrid-
˙ ing effect of the 20°C water on increasing M. It is
therefore unlikely that differences in depth of water immersion per se had profound effects on the thermal or cardiovascular responses during exercise after wa- ter immersion.
In conclusion, WBI and LBI attenuated Tc increases during submaximal exercise by producing a reduction i n T r e , w i t h W B I p r o d u c i n g a s l i g h t l y g r e a t e r c o o l i n g ˙ effect. Both treatments produced similar net S over the
entire protocol. However, LBI minimized metabolic increases and negative perceptual effects associated with WBI. Because of its similar thermal effect, re- duced metabolic and perceptual effects, and ease of use, LBI should be the preferred precooling method for patient populations that demonstrate impaired physi- cal function with increased internal temperature.
We acknowledge the technical support of Bob Shafer. We also thank all of the study participants for their time and cooperation.
This study was supported in part by a grant from the National Multiple Sclerosis Society.
Baker DG. Multiple sclerosis and thermoregulatory dysfunc- tion. J Appl Physiol 92: 1779–1780, 2002.
Bergh U and Ekblom B. Physical performance and peak aer- obic power at different body temperatures. J Appl Physiol 46: 885–889, 1979.
Bolster DR, Trappe SW, Short KR, Scheffield-Moore M, Parcell AC, Schulze KM, and Costill DL. Effects of precooling on thermoregulation during subsequent exercise. Med Sci Sports Exerc 31: 251–257, 1999.
Booth J, Marino F, and Ward JJ. Improved running perfor- mance in hot humid conditions following whole body precooling. Med Sci Sports Exerc 29: 943–949, 1997.
Burton AC. Human calorimetry. J Nutr 9: 261–280, 1935.
Castellani JW, Young AJ, Sawka MN, and Pandolf KB. Human thermoregulatory responses during serial cold-water immersions. J Appl Physiol 85: 204–209, 1998.
Drust B, Cable NT, and Reilly T. Investigation of the effects of the pre-cooling on the physiological responses to soccer-specific intermittent exercise. Eur J Appl Physiol 81: 11–17, 2000.
DuBois AB, Harb ZF, and Fox SH. Thermal discomfort of respiratory protective devices. Am Ind Hyg Assoc J 51: 550–554,
Epstein Y, Shapiro Y, and Brill S. Role of surface area-to- mass ratio and work efficiency in heat intolerance. J Appl Physiol 54: 831–836, 1983.
Gagge AP and Gonzalez RR. Mechanisms of heat exchange: biophysics and physiology. Handbook of Physiology. Environ- mental Physiology. Bethesda, MD: Am. Physiol. Soc., 1996, sect. 4, vol. I, chapt. 4, p. 45–84.
Hensel H. Thermoreceptors. Annu Rev Physiol 36: 233–249,
Hessemer V, Langusch D, Bruck LK, Bodeker RH, and Breidenbach T. Effect of slightly lowered body temperatures on endurance performance in humans. J Appl Physiol 57: 1731– 1737, 1984.
Holmer I. Body cooling with ice for warm-water diving opera- tions. Undersea Biomed Res 16: 471–479, 1989.
Hong SK, Lee CK, Kim JK, Song SH, and Rennie DW. Peripheral blood flow and heat flux of Korean women divers. Fed Proc 28: 1143–1148, 1969.
Kruk B, Pekkarinen H, Harri M, Manninen K, and Hanni- nen O. Thermoregulatory responses to exercise at low ambient temperature performed after precooling or preheating proce- dures. Eur J Appl Physiol 59: 416–420, 1990.
Lee DT and Haymes EM. Exercise duration and thermoregu- latory responses after whole body precooling. J Appl Physiol 79: 1971–1976, 1995.
Lee DT, Toner MM, McArdle WD, Vrabas IS, and Pandolf KB. Thermal and metabolic responses to cold-water immersion at knee, hip, and shoulder levels. J Appl Physiol 82: 1523–1530,
Martineau L and Jacobs I. Muscle glycogen utilization during shivering thermogenesis in humans. J Appl Physiol 65: 2046– 2050, 1988.
McArdle WD, Katch FI, and Katch VL. Exercise Physiology: Energy, Nutrition, and Performance. Baltimore, MD: Williams & Wilkins, 1996.
Nadel ER. Problems With Temperature Regulation During Ex- ercise. New York: Academic, 1977.
Olschewski H and Bruck K. Thermoregulatory, cardiovascu- lar, and muscular factors related to exercise after precooling. J Appl Physiol 64: 803–811, 1988.
Petajan JH, Gappmaier E, White AT, Spencer MK, Mino L, and Hicks R. Impact of aerobic training on fitness and quality of life of multiple sclerosis patients. Ann Neurol 39: 432–441,
1996. 23. Ramanathan NL. A new weighting system for mean surface temperature of the human body. J Appl Physiol 19: 531–533, 1964.
Weir JBDV. New methods for calculating metabolic rate with reference to protein metabolism. J Physiol 109: 1–9, 1949.
White AT, Wilson TE, Davis SL, and Petajan JH. Effect of precooling on physical performance in multiple sclerosis. Mult Scler 6: 176–180, 2000.
Wilson TE, Johnson SC, Petajan JH, Davis SL, Gappmaier E, Luetkemeier MJ, and White AT. Thermal regulatory re- sponses to submaximal cycling following partial body precooling. Eur J Appl Physiol 88: 67–75, 2002.
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