If you think that lifting weights gives you bigger and stronger muscles, you’d be right. If you think that they’re the same thing, you’d be wrong. Strength and size may be correlated, but they aren’t mutually exclusive.

So rather than focusing on how big your muscles are, instead we should focus on muscle density. This term refers to the strength versus size ratio, explains personal trainer Nancy Best: “Muscle density is associated with how strong your muscles are for their volume, which relates to the size of the muscle,” says Nancy Best.

Muscle density: why you should focus on strength, not size, of your muscles