Effect of aerobic training versus resistance training for improving cardiorespiratory fitness and body composition in middle-aged to older adults: A systematic review and meta-analysis of randomized controlled trials.

This systematic review and meta-analysis aimed to examine the influence of aerobic training (AT) versus resistance training (RT) on cardiorespiratory fitness and body composition in middle-aged to older adults. Four electronic databases including PubMed, Scopus, Cochrane CENTRAL, and web of science, as well as reference lists of included randomized controlled trials (RCTs) were searched from inception to April 2024. Data were pooled by the inverse-variance method and reported as mean differences (MDs) with 95 % confidence intervals (CIs). Thirty-eight RCTs, with a pooled sample of 1682 participants, met our inclusion criteria. Meta-analysis revealed that AT significantly improved VO/ (MD = 1.80, 95 % CI: 0.96 to 2.64, p < 0.0001) and 6-MWT (MD = 18.58, 95 % CI: 10.38 to 26.78, p < 0.00001), and significantly decreased body mass (MD = -1.23, 95 % CI: -1.98 to -0.47, p = 0.001) versus RT. However, changes in lean body mass favored RT over AT. Moreover, changes in VO/ and 6-MWT following AT were significant among both healthy and unhealthy participants, or men and women, after medium-term (< 24 weeks) and long-term (≥ 24 weeks) interventions, and among participants aged ≤65 and >65. Our results propose that AT should be considered an efficient approach to improving cardiorespiratory fitness and overall body composition with aging, particularly in terms of VO2max and 6-MWT performance. However, for improvements in lean body mass, RT may be more beneficial. Therefore, a combination of AT and RT might be optimal for comprehensive fitness and body composition improvements with aging.