Twenty-nine RCTs were included in the review (n=1,329). Sample sizes ranged from eight to 143 participants. Study quality ranged from 1 to 5 out of five (median 2).
Statistically significant reductions after progressive resistance training were found for total cholesterol (-5.5 mg/dL, 95% CI -9.4 to -1.6), total cholesterol/HDL-C (-0.5, 95% CI -0.9 to -0.2), non-HDL-C (-8.7 mg/dL, 95% CI -14.1 to -3.3), LDL-C (-6.1 mg/dL, 95% CI -11.2 to -1.0) and triglycerides (-8.1 mg/dL, 95% CI -14.5 to -1.8), but not HDL-C (0.7 mg/dL, 95% CI -1.2 to 2.6).
No statistically significant publication bias was found, but a large and statistically significant (p<0.001) amount of heterogeneity was observed across all lipid and lipoprotein outcomes (I2 range: 72% to 89%). The authors reported that they were unable to identify any significant sources of heterogeneity.
Statistically significant benefits were also found both for changes in percentage body fat and in lean body mass, but not for body weight or body mass index. Statistically significant associations were found between decreases in total cholesterol and decreases in body mass index, increases in upper body strength, fewer exercises and greater dropout rates.