hamstringscurl

The hamstring curl is a resistance exercise that isolates the hamstring muscles by flexing the knee against external resistance. It primarily targets the hamstrings, including the biceps femoris, semitendinosus, and semimembranosus, with minor involvement from the calves and glutes as stabilizers.

The exercise is most commonly performed on a leg curl machine, in lying or seated variants. Other forms include standing leg curls using a cable or ankle strap, and, in some training contexts, Nordic hamstring curls, which emphasize eccentric loading. The key is to position the body so that the knee joint is aligned with the machine’s pivot point and the resistance acts through the ankle or lower leg.

Technique and execution require a controlled approach. In setup, adjust the pad behind the ankles or calves and align the knee with the machine’s axis. Keep the hips and torso stable, and brace the core. During the curl, exhale as you bring the heel toward the glutes, squeezing the hamstrings at the end of the motion without rotating the hips or using momentum. Slowly return to the starting position with a controlled eccentric phase. A typical tempo is a short concentric motion followed by a longer, controlled eccentric.

Programming considerations vary by goals. For hypertrophy, common prescriptions are about 2–4 sets of 8–12 repetitions with progressive overload. For strength, lower reps with heavier loads may be used (e.g., 4–6 sets of 4–6 reps). Safety concerns include avoiding excessive range of motion, jerky movements, and overloading, especially for individuals with knee or lower-back issues. The hamstring curl can complement hip-dominant movements such as deadlifts and provides targeted development of knee flexors, contributing to knee stability and athletic performance.