• Photo for This or That: Lying vs. Seated Leg Curls
    Photo Credit: Andrew Giammarco

This or That: Lying vs. Seated Leg Curls

By Devin Wicks

Welcome to "This or That?", a weekly series in which I help demystify the different exercises you can do in the gym. There are many familiar exercises that seem very similar. But which should you do to accomplish what result? In this series, I'll try to give some answers. Not long ago, I compared two kinds of calf raises, seated and standing. But many guys prefer to use a machine for leg work. If so, this week's comparison is for you, since I am going to take a look at two exercises you can do on a leg machine: seated vs. lying leg curls.Turns out, they have some different nuances. Let's take a look.

Lying Leg Curls
For this exercise, lie face-down on the leg curl machine with ankles positioned under the ankle pads. Inhale and bend both legs, trying to bring your heels to your glutes. Slowly return to the starting position.

The basic leg curl is simple, right? But small changes will make big differences. Here are your options:

  1. Work the entire back of the leg: This exercise works the hamstring group (made up of the semimembranosus, biceps femoris—both short and long heads—and semitendinosus), as well as the upper calf muscle (the gastrocnemius) and the deeper popliteus, which aids the leg during flexion.
  2. Variations: This is a simple exercise, but small changes in position will shift the workload to different muscles. Be attentive to your form and you can really target your work. For instance, by adding a slight posterior pelvic tilt (a slight tuck of your tailbone), you relax the hamstrings a bit more and shift the workload toward the upper end of the long head of the biceps femoris and the semitendinosus. By pointing your toes (called "plantar flexion"), you can feel the effort in your hamstrings. When you flex your feet (dorsiflexion), you can feel the effort in your gastrocnemius.
The lying leg curl has a lot of potential for working hamstrings and calves. But its sibling, the seated leg curl, provides diversified hamstring work, again with variations.

Seated Leg Curls
If you want to hit the hamstrings from a different angle, try the seated leg curl. In this exercise, you sit at the machine with your legs extended and your ankles resting on the pad. Your thighs should be held in place by the thigh pad and your seat. Your objective is to press the pad under your ankles down and back under you. As you begin the movement, you inhale and draw your heels under your seat as though trying to touch your heels to your bottom. Slowly return to the start position.

Here are the benefits of seated leg curls:
  1. Hamstring intensive: This exercise works the same hamstring group as the lying leg curl (for those who like Latin, that's the semimembranosus, biceps femoris—short and long heads—and semitendinosus) as well as the deeper popliteus. The major difference is that, while the seated curl does engage the gastrocnemius, it does so to a lesser extent than the lying leg curls. This is much more of a hamstring isolation exercise.
  2. Subtle changes: For guys who do a lot of leg work, the seated leg curl allows isolation of the different parts of the hamstring. You can really be a specialist with this exercise. For variations, try turning your toes inward, focusing more work on the semimembranosus and the semitendinousus. Turning your toes outward, on the other hand, will shift the focus to the short and long heads of the biceps femoris.
Let's sum up: The lying leg curl hits the entire back of the leg, hamstrings and calves. You can add variation through your body position to shift that work, but if you want a hamstring isolation exercise, try the seated curls, and change your foot position to further direct your exertion.

About Devin Wicks: Devin Wicks (ACSM-HFI, USAW Club Coach) is creator of the RealJock Strength Foundation 12-Week Workout program and the fitness operations director at the University of California, Berkeley, where he acts as specialty strength coach for some of the university's premier sports teams, and is coordinating a pioneering new campus employee wellness program.