You can get stronger, bigger, and more enduring muscles by doing one tough set followed by lighter ones without resting—faster than doing multiple heavy or light sets.

Doing a heavy set followed by lighter ones without resting can help you do more reps with light weights, just like doing only light curls.

Doing a heavy set of arm curls followed by lighter ones without resting can make you stronger in one-rep max and static strength, just like doing only heavy curls.

Doing a tough set of arm curls followed by lighter sets without resting can make your biceps grow just as much as doing only heavy or only light curls over 8 weeks.

Doing one heavy set plus lighter ones without resting takes less time than doing three full sets of heavy or light curls.

If you do weight training with a break every few weeks to go lighter, you’ll build muscle and get stronger just as much as if you kept pushing hard the whole time — at least for guys who’ve never trained before.