The Effects of Ischemic Preconditioning on Human Exercise Performance

Background Ischemic preconditioning (IPC) is the exposure to brief periods of circulatory occlusion and reperfusion in order to protect local or systemic organs against subsequent bouts of ischemia. IPC has also been proposed as a novel intervention to improve exercise performance in healthy and diseased populations. Objective The purpose of this systematic review is to analyze the evidence for IPC improving exercise performance in healthy humans. Methods Data were obtained using a systematic computer-assisted search of four electronic databases (MEDLINE, PubMed, SPORTDiscus, CINAHL), from January 1985 to October 2015, and relevant reference lists. Results Twenty-one studies met the inclusion criteria. The collective data suggest that IPC is a safe intervention that may be capable of improving time-trial performance. Available individual data from included studies demonstrate that IPC improved time-trial performance in 67 % of participants, with comparable results in athletes and recreationally active populations. The effects of IPC on power output, oxygen consumption, rating of perceived exertion, blood lactate accumulation, and cardiorespiratory measures are unclear. The within-study heterogeneity may suggest the presence of IPC responders and non-responders, which in combination with small sample sizes, likely confound interpretation of mean group data in the literature. Conclusion The ability of IPC to improve time-trial performance is promising, but the potential mechanisms responsible require further investigation. Future work should be directed toward identifying the individual phenotype and protocol that will best exploit IPC-mediated exercise performance improvements, facilitating its application in sport settings.