Using light weights until you're exhausted or slow builds your muscle stamina better than heavy weights, but doesn't make you as strong as lifting heavy weights.

Lifting weights until you can't lift anymore makes muscles grow bigger no matter how heavy the weights are, but using heavier weights builds more strength than lighter ones.

Lifting heavy weights until you can't lift anymore makes young male athletes much stronger than lifting light weights over 8 weeks, even if both make muscles grow about the same size.

Lifting lighter weights until you can't lift anymore doesn't make you as strong as lifting heavier weights, even though both make your muscles grow about the same size.

Lifting lighter weights many times until you can't do more improves muscle endurance better than lifting heavy weights just a few times, especially for people who already work out.

Two different ways of lifting weights—pre-exhaustion and traditional—both help you get stronger and last longer during exercise about the same amount.