The influence of upper-body pre-cooling on repeated sprint performance in moderate ambient temperatures.
In this study, we examined the effects of upper-body pre-cooling before intermittent sprinting exercise in a moderate environment. Seven male and three female trained cyclists (age 26.8+/-5.5 years, body mass 68.5+/-9.5 kg, height 1.76+/-0.13 m, V O2peak 59.0+/-11.4 mL. kg(-1). min(-1); mean+/-s) performed 30 min of cycling at 50% V O2peak interspersed with a 10-s Wingate cycling sprint test at 5 min intervals. The exercise was performed in a room controlled at 22 degrees C and 40% relative humidity. In the control session, the participants rested for 30 min before exercise. In the pre-cooling session, the participants wore the upper segment of a liquid conditioning garment circulating 5 degrees C coolant until rectal temperature decreased by 0.5 degrees C. Rectal temperature at the start of exercise was significantly lower in the pre-cooling (36.5+/-0.3 degrees C) than in the control condition (37.0+/-0.5 degrees C), but this difference was reduced to a non-significant 0.4 degrees C throughout exercise. Mean skin temperature was significantly lower in the pre-cooling (30.7+/-2.3 degrees C) than in the control condition (32.5+/-1.6 degrees C) throughout exercise. Heart rate during submaximal exercise was similar between the two conditions, although peak heart rate after the Wingate sprints was significantly lower in the pre-cooling condition. With pre-cooling, mean peak power (909+/-161 W) and mean overall power output (797+/-154 W) were similar to those in the control condition (peak 921+/-163 W, mean 806+/-156 W), with no differences in the subjective ratings of perceived exertion. These results suggest that upper-body pre-cooling does not provide any benefit to intermittent sprinting exercise in a moderate environment.
Cheung
Stephen
S
Environmental Ergonomics Laboratory, School of Health and Human Performance Dalhousie University 6230 South Street Halifax Nova Scotia B3H 3J5 Canada. stephen.cheung@dal.ca
Robinson
Alicia
A
D000328:Adult; D001642:Bicycling / Q000502:physiology*; D001831:Body Temperature / Q000502:physiology*; D003020:Clothing; D003080:Cold Temperature; D005080:Exercise Test; D005221:Fatigue / Q000517:prevention & control; D005260:Female; D005334:Fever / Q000517:prevention & control; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D012881:Skin Temperature / Q000502:physiology*; D013997:Time Factors