When untrained young men lift weights with different heavy loads but equal total work, their chest muscles grow about the same amount—around 10-11% bigger.

If you do the same total amount of weightlifting work, lifting heavy weights a few times or lighter weights more times gives about the same muscle growth in the chest for beginners doing bench press, showing that the total work matters more than how many reps you do.

When you lift weights, how much total work you do matters more for getting stronger and bigger than whether you use heavy weights with few reps or light weights with many reps.

Doing more sets of weightlifting each week helps you build more muscle, but after a certain point, adding even more sets gives you less extra benefit.

Doing more weightlifting each week helps you build more muscle—but only up to a point. After a certain number of sets, doing even more doesn’t help much more.

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.