Lifting heavy weights to the point of exhaustion three times a week for six weeks makes untrained young men much stronger than lifting lighter weights, even though both types of training build similar amounts of muscle size.

Lifting heavy weights three times a week for six weeks makes untrained young men much stronger than lifting light weights, even though both groups gain about the same amount of muscle size.

Lifting heavy weights until you can't lift anymore makes young male athletes much stronger than lifting light weights over 8 weeks, even if both make muscles grow about the same size.

If you're already someone who lifts weights, doing light weights twice a week until you can't do more reps can make your muscles bigger and stronger in just 8 weeks.

Lifting heavy weights until you can't lift anymore makes young male athletes much stronger than lifting lighter weights over 8 weeks, showing that heavier loads train muscles and nerves better.

You can get stronger and bigger muscles by lifting light weights until you're exhausted — even if you never lift heavy, which challenges the old idea that heavy weights are required.