Neoprene thigh sleeves and muscle cooling after exercise.

CONTEXT: Neoprene sleeves are alleged to increase heat in skeletal muscle, but no published research supports this belief. OBJECTIVES: To quantify anterior thigh skin and intramuscular temperature changes in varsity athletes wearing a neoprene thigh sleeve. DESIGN: A 2 x 2 x 3 x 5 factorial design with replicated measures on 3 variables. Independent variables included sex (male or female), neoprene sleeve (yes or no), exercise intensity (control, 50% intensity bicycle, 70% intensity bicycle), and exercise phase (5 minutes pre-exercise, 15 minutes of exercise, 0-10 minutes postexercise, 11-20 minutes postexercise, 21- 30 minutes postexercise). SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: 12 male (23 +/- 0.95 years) and 12 female (20.59 +/- 1.44 years) National Collegiate Athletic Association Division I collegiate athletes actively engaged in offseason strength and conditioning programs. INTERVENTION(S): We sampled skin and muscle temperatures every 10 seconds for 50 minutes with a telethermometer interfaced to a personal computer. Each 60-minute session included 15 minutes pre-exercise (temperatures recorded during the last 5 minutes), 15 minutes of exercise (control, 50% intensity, and 70% intensity), and 30 minutes postexercise. Skin temperature was measured on the anterior aspect of the thigh using surface thermocouples. Intramuscular temperature was measured in the vastus lateralis muscle at a depth of 2 cm below the subcutaneous fat using implantable thermocouples. MAIN OUTCOME MEASURE(S): Skin and intramuscular temperature. RESULTS: Skin temperature was greater when subjects were wearing neoprene sleeves (1.4 degrees C during control, 3.1 degrees C during 70% exercise). Wearing a thigh sleeve had no effect on intramuscular temperature before or during exercise, but postexercise temperatures averaged 0.5 degrees C higher. Exercise intensity showed 1.3 degrees C to 2.0 degrees C increases in temperature with the sleeve. Females had higher intramuscular temperatures than males when wearing sleeves (1.4 degrees C during control, 1 degrees C during 50% exercise, and 0.8 degrees C during 70% exercise). Males had higher skin temperatures than females (0.8 degrees C during 50% exercise, 1 degrees C during 70% exercise). CONCLUSIONS: Neoprene sleeves are effective in maintaining intramuscular temperature after 15 minutes of exercise and in increasing skin temperature during and after exercise. These results may be attributable to the insulating effects of the neoprene sleeve.