Doing a single-muscle exercise before a bigger workout makes your muscle work harder and grow more because it gets tired first.

Doing single-muscle exercises first makes you tired, so you can build muscle with lighter weights on bigger exercises.

When people lift weights until they can't do another rep, their muscles grow about the same amount whether they use heavy or light weights — and how much they grow depends more on their own body than on how heavy the weights are.

Doing a special warm-up before lifting weights lets you finish your workout faster while still building just as much muscle.

Doing a light warm-up set before lifting heavy weights might help you build more muscle and get stronger, according to some research that tried a similar but different approach.

When healthy young men lift weights until they're too tired to continue, their muscles grow about the same amount in both their arms and legs, no matter how heavy the weights are.