This systematic review aimed to: 1) explore muscular fitness adaptations (e.g., muscle mass, muscle strength, functional performance) in older adults (≥ 60 years) following exercise with resistance training compared to control; and 2) investigate the moderating effects of load intensity, training frequency, and movement velocity on muscular fitness adaptations.

Four databases were searched (April 2024, updated 2025). Pooled effects for each outcome were summarized using Standardized Mean Difference (Hedges’ g) through a three-level meta-analysis model, and subgroup was used to explore moderators. The certainty of evidence was assessed using the GRADE approach.

Sixteen studies were eligible (n = 801), with data available from fifteen moderate quality randomized controlled trials. Compared to control, resistance training was effective in improving muscle mass (g = 0.16, I² = 67%), muscle strength (g = 0.55, I² = 11%), and functional performance (g = 0.76, I² = 62%). Muscular fitness was significantly moderated by load intensity, frequency, and movement velocity. SubmaxV (g = 0.47) resistance training with low intensity (g = 0.79) and high frequency (g = 0.79) was superior for improving muscle mass. SubmaxV (g = 0.56) resistance training with moderate intensity (g = 0.63) and moderate frequency (g = 0.55) was superior for improving muscle strength. MaxV (g = 0.93) resistance training with moderate intensity (g = 0.71) and low frequency (g = 0.64) was superior for improving functional performance

Resistance training effectively enhances muscular fitness in older adults. Load intensity, frequency, and movement velocity (SubmaxV was better for muscle mass and muscle strength compared to MaxV, and MaxV for functional performance) may significantly modulate improvements in muscular fitness adaptations.

CRD42023489470