When older men and women over 60 do strength training, men tend to gain more total muscle mass than women, but when you account for their starting size, both sexes improve at about the same rate.

A randomized controlled trial enrolling healthy adults ≥60 years, stratified by sex, assigning equal numbers of males and females to a standardized, supervised resistance training program (e.g., 3x/week, 70-80% 1RM, 3 sets of 8–12 reps) for 12–24 weeks, with whole-body fat-free mass measured by DXA at baseline and endpoint, and comparing absolute and relative changes between sexes.

A prospective cohort study following healthy adults ≥60 years who self-select into resistance training programs, measuring whole-body fat-free mass via DXA at baseline and after ≥12 weeks of training, comparing absolute and relative gains between males and females while adjusting for baseline differences and training volume.

A meta-analysis pooling individual participant data from published RCTs of resistance training in adults ≥60 years, comparing absolute and relative changes in whole-body fat-free mass between males and females, using standardized effect sizes and subgroup analysis by sex.

A cross-sectional analysis of existing pre-post resistance training data from multiple studies, comparing absolute and relative fat-free mass changes between older males and females without randomization or control for training dose.

A case-control study comparing older males and females who are classified as high responders (top 25% absolute FFM gain) versus low responders (bottom 25%) to resistance training, to determine if sex predicts response magnitude.