Triceps muscles anatomy The triceps (also known as the triceps brachii) is the muscle behind the arm, opposite of the bicep — and they get their name due to being made up of three different muscles.

Work triceps extensions into your upper body days —ideally two to three times a week. Like all triceps moves, these are great to pair with a bicep exercise for balance, Bonney says.

How to do tricep extensions How to: Stand with feet hip-width apart, holding one dumbbell in your hands. Bring the weight overhead, extending your arms straight so the dumbbell is above your head ...