For older people lifting weights, doing just one set of exercises builds just as much strength as doing four sets—so more sets don’t necessarily mean stronger muscles.

If you're an older adult who gets stronger with just a little bit of weight training, doing more sets won't make you any stronger than doing just one set.

For older people, lifting weights once or four times a week might not make much difference in how much stronger they get—but it could make a big difference in how much their muscles grow.

If you're an older adult who gets stronger with just a little bit of weight training, doing more sets won't make you any stronger than doing just one set.

If you're an older adult who's already getting stronger from light weight training, doing even more weight training might help you build even more muscle—but not as much as it helps people who didn't respond to light training at all.

When older men get stronger quickly at the start of weight training, it’s often just because they’re learning how to lift better—not because their muscles are growing or getting stronger for real. So, early gains don’t mean they’ll keep getting stronger over time.