Lifting light or heavy weights to exhaustion for 12 weeks didn’t change body fat or muscle mass in women who had never lifted before.

Doing light weight exercises until you can't do any more for 8 weeks won't make your arms stronger or more powerful if you're new to lifting — you probably need to lift heavier or move faster to see real gains.

After 12 weeks of lifting weights, both strong and weak older women gained about the same amount of muscle—starting strength didn’t affect how much muscle they built.

Even if overweight, postmenopausal women lift weights while eating fewer calories, their body’s use of protein doesn’t change much—but they still keep their muscle mass.

Even though your body releases similar growth hormones after light workouts whether you rest a little or a lot, you still get stronger and bigger muscles either way.

Using light weights for arm exercises can make your arms slightly more muscular, but using light or heavy weights for leg exercises doesn’t change leg muscle size in young women who haven’t trained before.