If skull crushers have always seemed...intimidating to you (seriously, that name isn't too enticing), don't be scared. They're actually a great triceps -toning moveand I promise they're not as ...

Skull crushers are a great move to include in your upper-body workout routine. The move targets your triceps and can also help tone your arms and improve shoulder stability. The skull crusher, or ...

The Lying Triceps Extension helps to firm and strengthen the muscles on the back of the upper arm. Any movement that involves straightening the arm will involve the triceps, which consists of three ...

Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. Arm day can be one of ...