Lifting weights helps people build bigger, stronger muscles, probably because it makes their muscles produce more protein and release helpful signaling molecules that help them grow and work better.

Even though lifting weights makes your muscles bigger and more active, those changes don’t explain why you get stronger at dynamic movements but not at holding static positions — something else, like how your brain coordinates movement, might be more important.

Even lifting light weights, as long as you push until you can't do another rep, can build muscle just as well as lifting heavy weights in people who already train regularly.

Even though lifting weights makes your muscles bigger and more active, those changes don’t explain why you get stronger—meaning something else, like how your nerves coordinate movement, might be more important.

Doing varied weight workouts might hurt your muscles a little less than doing the same routine over and over—but you still gain just as much muscle, meaning you don’t need to feel wrecked to get stronger.

Getting stronger from lifting weights doesn’t always mean your muscles are getting bigger—and vice versa. Strength and size don’t go hand in hand.