Effects Of Cooling Vest On Thermoregulation In Male Undergraduates During Exercise In A Hot Environment

Objective:This study aims to evaluate the effectiveness of cooling vest on thermoregulation in male undergraduates during exercise in a hot environment,discussing the relationship between cooling vest and heat-related illness prevention,providing theoretical basis and practical guidance for further physical education and sports training.Methods:Thirteen participants majored in basketball of Shenyang Sport University volunteered this experiment.Each participant performed two exercise trials in a hot environment(temperature 33?,relative humidity 60%).One was the cooling vest exercise trail,and the other was the control exercise trail.The requirements of the training session were 60% maximum oxygen uptake of steady state cycling,the average workload was(115.4±9.2)W,time of exercising was 40 minutes on a cycle ergometer at a rotational speed of 60 rpm.Rectal temperature,skin temperature,heart rate were recorded at 1-minute interval,rating of perceived exertion and thermal sensation were recorded at 5-minute interval during exercise;reaction time were recorded immediately after exercise.Results:(1)In the cooling vest exercise trials and the control exercise tirals,at the beginning of exercise,rectal temperatures were(37.18±0.07)? and(37.10±0.09)? respectively,at the end of exercise,rectal temperatures were(38.13±0.17)? and(38.33±0.19)? respectively,rectal temperatures showed an increase tendency during exercise(P<0.05).The increasing rectal temperature value in the cooling vest exercise trials were significantly lower than those in the control exercise tirals which started from the 24 th minute till the end of the exercise(P<0.05).(2)In the cooling vest exercise tirals,at the beginning of exercise,mean skin temperatures were(33.68±0.16)?,at the end of exercise,mean skin temperatures were(34.62±0.33)?.Mean skin temperatures were not significantly increased(P>0.05).In the control exercise tirals,at the beginning of exercise,mean skin temperatures were(34.36±0.12)?,at the end of exercise,mean skin temperatures were(37.05±0.27)?.Mean skin temperatures showed an increase tendency(P<0.01).The increasing mean skin temperature value were significantly lower than those in the control exercise tirals which started from the 5th minute till the end of the exercise(P<0.01).(3)In the cooling vest exercise trials and the control exercise tirals,at the beginning of exercise,heart rates were(99.00±3.88)b/min and(86.46±3.33)b/min respectively,at the end of exercise,heart rates were(161.92±4.47)b/min and(169.08±4.49)b/min respectively,heart rate showed an increase tendency during exercise(P<0.01),the increasing heart rate value in the cooling vest exercise trials were significantly lower than those in the control exercise tirals which started from the 5th minute till the end of the exercise(P<0.05).(4)In the cooling vest exercise trials and the control exercise tirals,at the beginning of exercise,rating of perceived exertion were all 6,at the end of exercise,rating of perceived exertion were 15.00±0.82 and 17.69±0.64 respectively,rating of perceived exertion showed an increase tendency during exercise(P<0.05).Rating of perceived exertion in the cooling vest exercise trials were significantly lower than those in the control exercise tirals which started from the 5th minute till the end of the exercise(P<0.05).(5)In the cooling vest exercise trials and the control exercise tirals,at the beginning of exercise,thermal perception were 5 and 4.92±0.77 respectively,at the end of exercise,thermal perception were 7.00±0.28 and 7.69±0.13 respectively,thermal perception showed an increase tendency during exercise(P<0.05).Thermal perception in the cooling vest exercise trials were significantly lower than those in the control exercise tirals which started from the 5th minute till the end of the exercise(P<0.05).(6)In the cooling vest exercise trials and the control exercise tirals,body mass were significantly lower after exercise(P<0.01).In the cooling vest exercise trials and the control exercise tirals,the body mass difference value were(0.97±0.04)kg and(1.10±0.09)kg respectively,the differences between the two experimental conditions showed no statistical significance(P>0.05).(7)In the cooling vest exercise trials and the control exercise tirals,the reaction time error rates were 0.05% and 0.06% respectively,the differences between the two experimental conditions showed no statistical significance(P>0.05).Conclusions:(1)Exercising in a hot environment,cooling vest can inhibit the increase in rectal temperature,increasing the time that rectal temperature reach the critical temperature,thus extend the exercise period,playing an avtive role inextending the training period and then enhance the teaching effect.(2)Exercising in a hot environment,cooling vest can inhibit the increase in mean skin temperature,promote heat dissipation by skin during exercise,prevent heat-related illness in hot environment.(3)Exercising in a hot environment,cooling vest can improve rating of perceived exertion and thermal perception,slow down the fatigue caused by hyperthermia,guarantee the quality of physical education.