目的:探讨远隔缺血预适应(RIPC)是否能通过提高持拍类项目运动员的最大累积氧亏(MAOD)延长超大强度运动(110%VO2max)时间,以及无氧代谢系统供能的具体途径.方法:招募24名持拍类项目运动员(年龄22.2±2.0岁,身高174±9 cm,体重67.1±12.4 kg),参加5次运动测试,包括1次递增负荷、1次恒定负荷(40%、50%、60%、70%和80%VO2max)和3次超大强度(110%VO2max)运动测试.采用随机交叉对照试验设计,将受试者分为对照组(Control组)、安慰剂组(Placebo组)和RIPC组.实施方案采用双侧上肢加压,5个循环/次,每个循环包括5 min 缺血和5 min再灌注,RIPC组缺血压力220 mmHg;Placebo组缺血压力60 mmHg;Control组无任何干预.结果:RIPC组超大强度运动时间和MAOD均大于Placebo组和Control组(P<0.05);三组之间的MAODALT、无氧乳酸、无氧无乳酸和EPOC动力学曲线参数差异无统计学意义(P>0.05).RIPC组MAOD高于MAODALT(P<0.05),超大强度运动时间变化值随MAOD变化值的增加而增加(P<0.05).结论:RIPC通过增加MAOD提高持拍类项目运动员的超大强度运动表现,糖酵解供能能力增强是运动表现改善的潜在中介.
Objective To explore whether remote ischemic preconditioning(RIPC)can prolong the time of ultra-intense exercise(110%VO2max)by increasing the maximum cumulative oxygen deficit(MA-OD),and the specific ways of energy supply of the anaerobic metabolic system.Methods Twenty-four racquet athletes(22.2±2.0 years;174±9 cm;67.1±12.4 kg)completed three supramaximal intensi-ty tests on a treadmill at 110%VO2max intensity to exhaustion separated with Control,Placebo and RIPC interventions.RIPC was induced on the limbs on both sides(5×5 min alternating bilateral occlu-sion 220 and 60 mmHg for Placebo and RIPC interventions,respectively).Moreover,all groups under-went a fourth test with incremental load,and a fifth test with constant load at 40%,50%,60%,70%and 80%VO2max.Results The time to exhaustion and the MAOD of the RIPC group were both greater than those in the Placebo and Control groups(P<0.05).However,no significant differences were found in the average alternative maximal accumulated oxygen deficit(MAODALT),lactic anaerobic metabolism,alactic anaerobic metabolism and parameters of excess post-exercise oxygen consump-tion dynamic curve of the three groups(P>0.05).Meanwhile,in the RIPC group,the average MAOD was significantly higher than MAODALT(P<0.05).Pearson correlation analysis showed a significant rela-tionship between the improvement of MAOD and an increase in exhaustion time after RIPC interven-tion.Conclusion RIPC can improve supramaximal exercise performance of racquet athletes by enhanc-ing their MAOD,and the enhancement of glycolysis energy supply and lactic acid elimination is a po-tential intermediary of the improvement of sports performance.