Performing four sets of four repetitions during upper body workouts may lead to more muscle growth than doing three sets of eight to twelve repetitions, assuming the total number of repetitions is...

To achieve the greatest increase in muscle size, perform resistance exercises with more than 12 repetitions per set, pushing close to physical limit, and avoid combining these sets with sustained aerobic activity.

If you do the same total amount of weightlifting work, lifting heavier weights fewer times or lighter weights more times gives men about the same muscle growth.

For young men who regularly lift weights, the number of sets taken to muscular failure may better predict muscle growth than the total weight lifted or the number of repetitions performed, as long as the total number of sets is the same.

Doing around 31 sets per muscle group each week is the sweet spot for building muscle, and doing more than that won't give you noticeably better results.

When lifting weights until nearly exhausted, the amount of muscle growth is similar whether you use fewer repetitions with heavier weights or more repetitions with lighter weights.