ABSTRACT

　The ischemic preconditioning phenomenon was introduced in a study thatdemonstrated that repetitions of short-term ischemia and reperfusion of coronaryarteries could reduce the myocardial damage following prolonged ischemia （directeffect）．Moreover, it was later demonstrated that the ischemic preconditioningof coronary arteries also protects remote cardiac tissue that is not directly exposedto ischemic preconditioning （remote effect）．Because of the intermittent natureof the blood flow during intense muscle actions, it was proposed that ischemicpreconditioning prior to exercise could increase muscular performance. Although most of the exercise studies employed an ischemic preconditioning protocol involvingfour cycles of 5-min circulatory occlusion followed by a 5-min reperfusion period,the optimal number of repetitions of ischemic preconditioning remained unclear.First, we examined the effective repetition numbers （from one to four） of direct andremote ischemic preconditioning in lower leg on exercise performance and fatigability.Contrary to previous reports, the results showed that any repetition of ischemicpreconditioning did not affect the maximum strength and fatigability in knee extension.Concerning those negative results, we examined effects of ischemic preconditioningin a practical exercise of repeated-jump and combined ischemic preconditioning withdietary nitrate（ donor of nitric oxide）．However, we could not demonstrate significanteffects of ischemic preconditioning on exercise performance and muscle damage evenwith dietary nitrate.

DECENTE SPORTS SCIENCE Vol.40/The DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE