Effects of Ischemic Pre and Postconditioning on Indirect Markers of muscle damage: A Systematic Review and Meta-Analysis

Introduction. Exercise-induced muscle damage (EIMD) occurs following unaccustomed or eccentric exercise. Ischemic conditioning applied passively before (IPCb) or after (IPCa) exercise may mitigate EIMD. However, IPC effects on indirect markers of EIMD are not fully understood. Objective. To evaluate IPCb and IPCa effects on indirect markers of EIMD. Methods. We screened randomized clinical trials on PubMed, Scopus, Web of Science, SPORTDiscus, CENTRAL, CINAHL, and PEDro databases. We performed meta -analyses of mean differences (MD), standardized mean differences (SMD), and 95% confidence intervals (95% CI) using a random-effects model. To be included, studies had to evaluate at least one indirect marker related to EIMD, use some exercise modality to induce muscle damage, and use sham IPC or no intervention as a control group. Results. Nine studies reporting data from 178 individuals (174 males) were considered eligible. The outcomes included delayed-onset muscle soreness (DOMS), creatine kinase (CK) activity, limb circumference, maximum voluntary isometric contraction (MVIC), and jump height. IPCb reduced DOMS compared with control/sham (SMD: -2.8; 95% CI -3.67 to -1.92). IPCa had a positive effect on DOMS (SMD: -2.16; 95%CI - 3.94 to -2.03), CK activity (SMD: -1.39; 95%CI -2.26 to -0.51) and countermovement jump height (MD: 1.72; 95%CI 1.13-2.30) compared with control/sham. Conclusions. Our findings suggest that IPCb and IPCa mitigate DOMS. IPCa appeared to accelerate recovery for countermovement jump and attenuate the rise in CK activity compared with control/sham.