For people over 60, adding one extra day of weight training each week might help them get a little stronger, but it won’t make their muscles noticeably bigger.

If you lift weights more often each week, you’ll likely get stronger faster—but that doesn’t always mean your muscles will get bigger. Strength and muscle growth might not follow the same rules.

If you're a young guy lifting weights more often each week, you'll likely get stronger faster—but that doesn't mean your muscles will get noticeably bigger.

If you're over 60 and lifting weights, doing it more than twice a week probably won't make you any stronger or give you bigger muscles than doing it just twice a week.

Lifting weights three times a week instead of two makes your muscles grow bigger, no matter what type of muscle fibers you have — but it doesn’t make you stronger in one-rep max lifts.

If you lift weights the same total amount each week, it doesn’t really matter whether you do it in one big session or spread it out over several days—your muscles will grow about the same either way.