Even people in their 50s and 70s can get much stronger and activate their muscles better after 12 weeks of heavy weight training — age doesn’t stop them from improving.

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.

When older men and women over 60 start lifting weights, women tend to get stronger faster relative to how strong they were at the start—especially in their arms and legs—compared to men doing the same workout.

When older women lift weights for 8 weeks, their muscles don’t get much bigger, but they do get stronger and walk faster—so it seems like something other than bigger muscles is helping them move better.

When older men and women over 60 do strength training, the men tend to get stronger in their arms and legs than the women do, even when they’re doing the same workouts.

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.