For middle-aged and older adults, how fast your muscles can generate power might be a better sign of how long you'll live than how strong they are — especially in men.

If middle-aged or older adults don't have much muscle power for their weight — like when pulling motions — they're much more likely to die earlier than those who are stronger, even after accounting for things like belly fat and health conditions.

If you're an older adult, having weaker hand grip compared to your weight might be a little linked to a higher chance of dying from any cause, but it doesn't add much info beyond things like blood pressure or smoking.

Measuring how powerful your muscles are—relative to your size—might help doctors better predict your risk of dying from any cause, even after considering things like age, belly fat, and medical history. It seems to be especially helpful for women.

The stronger your upper body muscles are — even just a little bit stronger — the lower your chances of dying from any cause, and this seems to be true no matter how strong you already are.

Muscle power — how fast you can use your muscles — might be a better sign of how long you'll live than just how strong your muscles are, because it shows how well your body can handle real-life movements.