This research used meta-analysis to examine the effect of resistance training on children and youth. Studies investigating the effects of various forms of resistance training in participants of ages less than 18 years were analyzed. Effects sizes (ES) were calculated by gender, age group (boys ages > or = 16 years and girls ages > or = 14 years were defined as older), training (isokinetic, isometric, isotonic), and design type (pretest-posttest or experimental-control). Similar ESs were obtained for older and younger children; isotonic methods demonstrated larger ESs than isometric or isokinetic. Larger ESs were obtained in studies with cross-sectional (experimental-control) than pre-post designs. Resistance training appears to enhance muscular endurance and strength in children and youth. The magnitude of the effect appears to be a function of gender, training method, and experimental design.