Sliding Leg Curls

The sliding leg curl is a bodyweight hamstring curl — heels on sliders or a towel, hips bridged — and one of the hardest no-machine hamstring exercises. Lie on your back with your heels on sliders or a folded towel, arms by your sides. Drive your hips up into a bridge, then pull your heels toward your glutes by bending your knees, squeezing your hamstrings at the top. Extend your legs back out slowly — the 2–3 second lowering is where this exercise earns its reputation — and keep your hips bridged for the whole set. Scale it down by curling with both legs over a shorter range; scale it up with single-leg reps.