1. Lying on your back, point your legs upward and reach your hands around one ankle or calf; drop the other leg down to about 45 degrees.
2. Curl your head, neck, and shoulders up off the floor and look down at your core. Gently pulse the raised leg closer to your body (two times), as your hamstring allows.
3. Switch legs and repeat. Keep switching, and remember to keep your core pulled in the whole time.
You don’t need a lot of equipment—or any at all—to get fit. Check out this no-equipment workout: