When you use momentum (like swinging or cheating) to do exercises, you lift about twice as much total weight—but that extra work doesn't seem to make your muscles grow bigger than doing the exercise...

Using momentum to lift weights during resistance training lets people lift heavier weights, but the heavier weights do not necessarily mean the muscles have become stronger.

When lifting weights with a swinging motion instead of strict control, untrained people can lift more total weight, but this does not lead to bigger muscles. This suggests that how much tension is placed on the muscle matters more than the total amount of weight moved.

Using momentum to lift weights during isolated exercises does not lead to greater muscle growth in people who are new to training, even if they lift more total weight, because shifting the effort to other muscles doesn't help the intended muscle grow.

When lifting weights until complete fatigue, using momentum from body movement does not lessen muscle growth in the targeted muscles.

The total amount of work done (weight × reps × sets) seems to matter for muscle growth — more work generally leads to more muscle, even if the weights are light.