Place a dumbbell on its end next to the lower end of a flat bench.
Lie prone (on your front) on the bench, with your knees close to the edge.
Pinch the dumbbell between the arches of your feet.
Grasp the sides or legs of the bench for stability.
Execution
Keeping your legs and feet squeezed together, exhale as you curl the dumbbell up toward your buttocks. Make sure that the soles of your feet face the ceiling at all times.
Inhale as you slowly lower the dumbbell back toward the starting position until your knees are almost fully extended.
Repeat.
Comments and tips
The most difficult element of the dumbbell leg curl exercise is learning how to hold the dumbbell securely between your feet. This becomes increasingly trickier the heavier the dumbbell becomes. Therefore, start light until you get used to the exercise.
Do not curl the dumbbell until you are confident that it is being held securely between your feet.
When using a flat bench, you will experience less resistance at the top of the movement as your shins become vertical. You can fix this by elevating the front of the bench and producing an inclined surface. Just place a plate or two under the front legs.
To improve the mechanical leverage of your hamstrings, place a cushion or towel under your hips to raise them off the bench a little. Leg curl machines achieve this by having an angled bench.
The dumbbell leg curl is useful when you don’t have access to a leg curl machine. Otherwise, the leg curl machine is recommended for leg curls.