If you lift weights the same amount and with the same effort, holding your muscles still (isometric) builds muscle just as well as moving them up and down (dynamic).

For small muscle groups, unilateral and bilateral resistance training produce equivalent hypertrophic adaptations when volume and effort are matched.

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.

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.

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.

If you lift weights with machines or with free weights and do the same amount of work at the same effort level, you’ll build muscle just as well with either one — even if you’re already fit.