The effect of remote ischemic preconditioning on upper extremity strength in healthy male adults: an updated systematic review and meta-analysis.

BACKGROUND

Remote ischemic preconditioning (RIPC) is a non-invasive intervention involving brief, repeated limb ischemia and is suggested to enhance muscle performance. However, findings in healthy men remain inconsistent, and few studies have examined upper-limb strength. This meta-analysis provides the first quantitative synthesis of acute RIPC effects on upper-body strength in healthy male adults, aiming to clarify its efficacy and practical relevance.

METHODS

English (PubMed, Web of Science, Embase, Cochrane Library) and Chinese (CNKI, Wanfang, VIP, CBM) databases were systematically searched up to March 16, 2025. Randomized crossover trials examining acute RIPC effects on upper-limb strength in healthy male adults were included. Primary outcomes involved maximal, explosive, and endurance strength measures. The review was registered with PROSPERO (CRD420251184757). Data were pooled using random-effects models, and heterogeneity was assessed via the I² statistic. Prespecified subgroup analyses examined moderators such as RIPC protocol (cycle number/duration) and strength outcome type (maximal, explosive, endurance).

RESULTS

Six randomized crossover trials involving 84 participants met inclusion criteria. The meta-analysis showed a small, positive, but non-significant overall effect of RIPC on upper-limb strength (SMD = 0.24, 95% CI: -0.02 to 0.51, p = 0.07) with low-to-moderate heterogeneity (I² = 32%). Subgroup analyses revealed no significant effects for maximal (SMD = 0.03, p = 0.85) or explosive strength (SMD = 0.13, p = 0.75). A moderate but non-significant improvement was observed for strength endurance (SMD = 0.54, 95% CI: -0.01 to 1.10, p = 0.054) with moderate heterogeneity (I² = 60%). Neither the number of ischemia–reperfusion cycles (p = 0.40 for subgroup difference) nor the test time window (< 30 min vs. ≥ 30 min, p = 0.37) significantly moderated the effects.

CONCLUSION

This first meta-analysis on RIPC and upper-limb strength suggests that acute RIPC does not reliably improve upper-body strength in healthy male adults. Despite a moderate effect size observed for strength endurance, the lack of statistical significance and the 95% confidence interval crossing zero indicate considerable uncertainty in this finding. Together with the limited and heterogeneous evidence, this indicates that current protocols do not consistently enhance strength performance. RIPC should therefore be regarded as a theoretically promising but practically unverified approach. Larger, well-controlled trials are needed to determine whether specific RIPC parameters or time windows can produce reproducible performance gains.