For women who don't usually lift weights, doing lots of lighter reps or fewer heavy reps both build similar muscle size and make you stronger after two months.

A study found that for women new to weightlifting, doing many reps with lighter weights or fewer reps with heavier weights both built muscle and strength equally well over 8 weeks.

When women who haven't trained before do weightlifting for 8 weeks, they get much stronger (27-43% stronger) but their muscles don't grow much (only 3-4% bigger), showing that getting stronger happens faster than building bigger muscles at the start.

For women new to weight training, doing either many lighter reps or fewer heavier reps for 8 weeks gives about the same muscle growth in the thigh muscles, showing both methods work well for beginners.

For young women, doing lighter weightlifting for 10 weeks can build leg muscle just as well as heavier lifting, with muscle growth between 3% and 12%.

The muscle growth seen here — about 2% — is about what you’d expect from 10 weeks of regular weightlifting, based on other studies.