If you lift weights until your muscles are completely exhausted, it doesn't matter whether you do 6 reps or 35 reps per set—you will build the exact same amount of calf muscle either way.

When people who are already fit push themselves as hard as they can during weight training, it doesn't matter if they lift heavy weights for a few reps or lighter weights for many reps—both ways build muscle about the same.

Lifting lighter weights many times until you can't do any more builds as much muscle as lifting heavy weights a few times in people who already exercise regularly.

You can build just as much muscle by stopping a few reps short of total exhaustion as you can by going all the way to failure during weight training.

When people lift weights regularly, their muscles usually get about 5% bigger on average, no matter what kind of weight routine they follow.

You can still build muscle even if you don't push your sets to within five reps of total failure, which goes against the idea that only the last few tough reps really matter for growth.