When untrained young men lift lighter weights many times until they can't lift anymore, it builds just as much muscle in their calf muscles as lifting heavier weights fewer times. Both ways made...

If you do push-ups or bench presses with light weights until you can't do another rep, twice a week for two months, your arms and chest will grow just as much — so push-ups can be just as good as gym machines for building muscle, if you push yourself just as hard.

Even lifting light weights really slowly until you can't do another rep can make your muscles bigger, just like lifting heavy weights.

If you lift weights until you can’t do another rep—whether you use heavy weights or light ones—you’ll end up with about the same muscle growth after nine weeks, as long as you’re putting in the same effort and number of reps.

In recreationally trained young men, performing resistance exercises to muscular failure three times per week for nine weeks leads to measurable increases in muscle thickness in several major muscle groups, whether using heavy or light weights.

When untrained young men lift weights until they can't lift anymore, their calf muscles grow bigger by 7-14%, no matter how heavy the weights are. This shows that pushing hard is what makes muscles grow, not how heavy the weight is.