Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Brands

Lock Icon

Unlock this article and unwrap savings this holiday season.

Already have an Outside Account? Sign in

Outside+ Logo

Now 30% Off.
$4.99/month $3.49/month*

Get the one subscription to fuel all your adventures.


  • Map your next adventure with our premium GPS apps: Gaia GPS Premium and Trailforks Pro.
  • Read unlimited digital content from 15+ brands, including Outside Magazine, Triathlete, Ski, Trail Runner, and VeloNews.
  • Watch 600+ hours of endurance challenges, cycling and skiing action, and travel documentaries.
  • Learn from the pros with expert-led online courses.
Join Outside+

*Outside memberships are billed annually. You may cancel your membership at anytime, but no refunds will be issued for payments already made. Upon cancellation, you will have access to your membership through the end of your paid year. More Details

Exercise Library

Stability-ball Hamstring Curl

Lie with your ankles balanced on top of a stability ball, legs together, while your head, shoulders and arms are flat on the floor. Your body should form a bridge from your feet to your upper spine. From this position, flex your hamstrings to bend your knees and roll the ball toward you, with your heels approaching your glutes. When your knees are fully bent, squeeze the contraction for a count, then slowly roll the ball back to the start. Repeat for reps.