Effects of Cold-water Immersion and Partial Body Cryotherapy on Post-exercise Recovery of Football Players in Hot and Humid Environment

Objective:To investigate the effects of cold-water immersion (CWI) and partial body cryotherapy (PBC) on post-exercise recovery of football players in hot and humid environment,so as to provide references for choosing reasonable and effective cold treatment method in football practice.Methods:Sixteen football players performed a specific combination of aerobic and anaerobic training in hot and humid environment (temperature:35℃~38℃,humidity:60%~70%),and then they recovered in a passive way (control,CON),or cold-water immersion,or partial body cryotherapy in normal temperature and humidity environment(temperature:20℃~25℃,humidity:40%~50%) in three sessions,respectively.The optimal recovery method was explored by analyzing the body temperature,heart rate variability,reaction time and vertical jump ability.Results:The interactive effects of cold treatment and time on core temperature was significant (F_10,84=9.241,P<0.001,η_partial²=0.524).There was no significant difference in the heart rate variability of cold-water immersion group before and after intervention.The reaction time of control after intervention was significantly lower than before intervention (t=3.340,P=0.005).There was no significant difference in reaction time between the cold-water immersion and the partial body cryotherapy group.After the intervention,the average vertical jump height and jump time,the maximum vertical jump height and jump time of single jump were significantly lower than that of before intervention in cold-water immersion group (t=7.150,P<0.001;t=6.870,P<0.001;t=7.576,P<0.001;t=7.081,P<0.001).After the intervention,the average vertical jump height and the functional index of the phosphagen system of 10 seconds of continuous vertical jump were significantly lower than that of before intervention in cold-water immersion group (t=5.918,P<0.001;t=5.647,P<0.001).Conclusion:Both cold-water immersion and partial body cryotherapy can quickly reduce core temperature and reaction time.Cold-water immersion can promote recovery by enhancing the activity of vagus nerve and promoting parasympathetic nerve activation,but it can also reduce the vertical jump performance.If the one who have no more training in a short time,the recovery effect of cold-water immersion was better than that of partial body cryotherapy.