The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
Med Sci Sports Exerc. 2011 Jul;43(7):1280-6. doi: 10.1249/MSS.0b013e318206845d.
Remote ischemic preconditioning (RIPC) induced by transient limb ischemia releases a dialysable circulating protective factor that reduces ischemia-reperfusion injury. Exercise performance in highly trained athletes is limited by tissue hypoxemia and acidosis, which may therefore represent a type of ischemia-reperfusion stress modifiable by RIPC.
National-level swimmers, 13-27 yr, were randomized to RIPC (four cycles of 5-min arm ischemia/5-min reperfusion) or a low-pressure control procedure, with crossover. In study 1, subjects (n=16) performed two incremental submaximal swimming tests with measurement of swimming velocity, blood lactate, and HR. For study 2, subjects (n=18) performed two maximal competitive swims (time trials). To examine possible mechanisms, blood samples taken before and after RIPC were dialysed and used to perfuse mouse hearts (n=10) in a Langendorff preparation. Infarct sizes were compared with dialysate obtained from nonathletic controls. RIPC released a protective factor into the bloodstream, which reduced infarct size in mice (P<0.05 for controls and swimmers). There was no statistically significant difference between the effect of RIPC and the low-pressure control protocol on submaximal exercise performance. However, RIPC was associated with a mean improvement of maximal swim time for 100 m of 0.7 s (P=0.04), an improvement in swim time relative to personal best time (-1.1%, P=0.02), and a significant improvement in average International Swimming Federation points (+22 points, P=0.01).
RIPC improves maximal performance in highly trained swimmers. This simple technique may be applicable to other sports and, more importantly, to other clinical syndromes in which exercise tolerance is limited by tissue hypoxemia or ischemia.
通过短暂肢体缺血诱导的远程缺血预处理（RIPC）释放可透析的循环保护因子，减少缺血再灌注损伤。高度训练的运动员的运动表现受到组织缺氧和酸中毒的限制，因此这可能代表一种可通过 RIPC 改变的缺血再灌注应激类型。
国家级游泳运动员，年龄 13-27 岁，随机分为 RIPC（四组 5 分钟手臂缺血/5 分钟再灌注）或低压对照程序，交叉。在研究 1 中，受试者（n=16）进行了两次递增的亚最大游泳测试，测量游泳速度、血乳酸和 HR。对于研究 2，受试者（n=18）进行了两次最大的竞技游泳（计时赛）。为了研究可能的机制，在 RIPC 前后采集的血液样本进行透析，并用于在 Langendorff 制剂中灌注小鼠心脏（n=10）。与非运动员对照组获得的透析液比较梗死面积。RIPC 将一种保护因子释放到血液中，这降低了小鼠的梗死面积（对照组和游泳运动员的 P<0.05）。RIPC 与低压对照方案对亚最大运动表现的影响之间没有统计学上的显著差异。然而，RIPC 与 100 米最大游泳时间的平均改善 0.7 秒（P=0.04）相关，相对于个人最佳时间的游泳时间改善（-1.1%，P=0.02），以及平均国际游泳联合会点数的显著改善（+22 点，P=0.01）。
RIPC 提高了高度训练的游泳运动员的最大运动表现。这种简单的技术可能适用于其他运动，更重要的是，适用于其他运动中运动耐量受到组织缺氧或缺血限制的临床综合征。
