Effects of Ischemic Preconditioning on Aerobic Capacity in Healthy Adults: A Systematic Review and Meta-Analysis

Abstract

Abstract Background: Ischemic preconditioning (IPC) may be a promising strategy to improve aerobic capacity in healthy adults, while such effects have not been comprehensively characterized. This systematic review and meta-analysis aimed to examine the effects of IPC intervention on aerobic capacity in healthy adults. Methods: Studies with randomized controlled or crossover designs exploring the effects of IPC as compared to no intervention or placebo control on time trial performance (TTP), time to exhaustion (TTE), maximal oxygen uptake (VO2max), peak oxygen uptake (VO2peak), and blood lactate (BLA) in healthy adults were included. The data (M ± SD) were extracted from included studies and converted into mean difference (MD) by calculating fixed-effect meta-analysis. Subgroup analysis was used to examine the characteristics of IPC intervention, participants, and exercise tests. Results: Twenty publications consisting of 297 participants were included. The overall analysis showed that TTE significantly improved after IPC intervention compared with the control [MD = 31.78, 95%CI (17.67, 45.89), P < 0.01]. In subgroup analysis, TTE was significantly improved only in acute intervention conditions [MD = 31.50, 95%CI (17.12, 45.88), P < 0.01], in untrained participants [MD = 50.37, 95%CI (30.47, 70.27), P < 0.01], and assessed by cycling exercise tests [MD = 46.51, 95%CI (26.21, 66.82), P < 0.01]. However, no significant effect was observed on TTP [MD = −1.75, 95%CI (−8.79, 5.29), P = 0.63], VO2max/VO2peak [MD = 0.10, 95%CI (−1.02, 1.21), P = 0.87], and BLA [MD = 0.26, 95%CI (−0.05, 0.57), P = 0.10] in healthy adults after IPC intervention. Conclusions: This meta-analysis provides moderate evidence that IPC intervention cannot induce significant improvement in aerobic capacity, but it improves the tolerance of the training intensity and fatigue recovery in healthy adults. IPC intervention might be effective (i) in acute intervention conditions, (ii) in untrained athletes or beginner athletes, and (iii) in exercises dominated by the muscles at the position of the intervention. Systematic review registration: www.crd.york.ac.uk/PROSPERO/, identifier: CRD42023407412.