When people who’ve never lifted weights before train their chest and arms with the same total muscle tension time, the back part of their triceps (near the elbow) grows more than the middle or shoulder-end parts.

When two different ways of lifting weights are adjusted so that the total time your muscles are under strain is the same, both ways lead to about the same strength gains and muscle growth in people who haven’t trained before.

If you're a young guy who hasn't trained much before, doing exercises like the bench press will make the back part of your triceps grow way more than just doing arm-only exercises like lying triceps extensions.

When guys who work out a little bit lift heavy weights (85% of their max), their triceps muscles grow faster and more reliably than when they lift light weights (30% of their max)—so how heavy you lift might change when your muscles start getting bigger.

Even after a super hard chest workout, the size of the triceps muscles goes back to normal within a day—meaning the workout didn’t actually tear them up much.

If you're a guy who hasn't trained much before, your triceps muscle in the back of your arm grows about the same no matter if you do push-ups, triceps extensions, or a mix of both — the type of exercise doesn't really matter for this part of the muscle.