If you lift heavy weights for fewer reps and lighter weights for more reps but do the same total work, you'll build about the same muscle size, but you'll get stronger faster with the heavy weights.

Lifting very heavy weights a few times with long breaks builds more muscle and strength faster than lifting lighter weights many times with short breaks, when the total amount of lifting isn't the same.

If you do the same total amount of lifting, whether you lift heavy weights for fewer reps or lighter weights for more reps, you'll build about the same amount of muscle as a beginner.

Lifting heavy weights with fewer reps and longer breaks builds more muscle and strength than lifting lighter weights with more reps and shorter breaks in men who already work out.

For young guys who don't usually exercise, doing one set or three sets of heavy lifting doesn't make a big difference in muscle growth, but three sets might have a small, not-proven benefit.

If you do the same total amount of weightlifting work, lifting heavy weights with longer breaks and lifting lighter weights with shorter breaks both build muscle about the same, but lifting heavy gives you more strength.