Systematic review of the effects of concurrent training on maximal oxygen uptake and skeletal muscle mitochondrial adaptation: A meta-analysis.

This meta-analysis evaluated the effects of concurrent training (combining resistance and endurance trainings, CT) versus endurance training (ET) alone on maximal oxygen uptake (VO2max) and muscle mitochondrial adaptation. Following PRISMA guidelines, systematic searches were conducted in PubMed, Embase, Cochrane Library, CNKI, Wanfang, and CBM databases. Standardized mean differences (SMDs) with 95% confidence intervals were calculated to compare outcomes between the two groups. Overall, no significant difference in VO2max was observed between CT and ET groups (SMD: -0.12 [-0.28, 0.05]; p > 0.05). However, in untrained individuals and 16 weeks of training, CT involving reduced ET load was related to attenuated VO2max increase (SMD: -0.32 [-0.62, -0.02] and -0.63 [-1.21, -0.06], respectively; p < 0.05). Muscle mitochondrial adaptation markers (citrate synthase activity, state 3 respiration, protein synthesis rate, and PGC-1α mRNA) all showed no significant differences between the two groups (p > 0.05). There are no significant differences in the changes of VO2max and skeletal muscle adaptation in the overall or athletic population between CT and ET. However, reduced ET load of CT is associated with smaller VO2max gains in the untrained population or 16 weeks of intervention. There are no significant differences in the changes of VO2max and skeletal muscle adaptation in the overall or athletic population between CT and ET. However, reduced ET load of CT is associated with smaller VO2max gains in the untrained population or 16 weeks of intervention.