Why Single-Leg Exercises Are an Important Part of Jessica Biel's Fitness Routine

Improve stability, balance, and functionality with these lower-body moves.

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Jessica Biel has been a dedicated fitness buff for quite some time. The actress and Gaiam spokeswoman played club soccer as a teen, picked up yoga in her 20s, and today, turns to yoga and circuit training to stay in shape.

Now, thanks to an admission by her trainer Jason Walsh (who also works with Emma Stone, Alison Brie, and Brie Larson), we know another major secret behind Biel's strength: single-leg exercises.

Walsh and Biel do "any and every type of single-leg exercise you can think of,” the LA-based celebrity trainer and founder of Rise Movement and Rise Nation recently told PopSugar. These specific exercises—including single-leg deadlifts, single-leg hip thrusts, and single-leg squats—”help with functionality and balance,” Walsh added.

A single-leg exercise is simply any lower-body move that you do with the support and power of just one leg. A single-leg squat, for example, involves raising one leg off the floor and performing the squat motion with just the strength of one leg.

Single-leg exercises can help pinpoint muscle imbalances, and they help improve balance and core stability.

Isolating one side of the body during an exercise move can help identify any muscle imbalances in the body, Emily Schromm, Denver-based certified personal trainer and nutritionist, tells SELF. “Most people are asymmetrical,” she says, meaning we typically favor one side of our body over the other. If you’re right-handed, you’re likely “right-legged” as well, she explains.

“When you cross your legs or walk up stairs, notice which leg you lead with,” Schromm says. Repeatedly favoring one side of the body results in an imbalance of strength, which over time can lead to chronic pain and injury if it's big enough for you to notice. That's because an imbalance will cause certain muscles to overcompensate and work harder than they should, which increases the risk you'll overwork and hurt them.

Single-leg movements—also called unilateral exercises—can also help you fix an imbalance. By working with one side of the body at a time, you don't give the other side the chance to take over—so you're basically forcing each leg to do the work without relying on any other help. That's also what makes them great for challenging and improving your balance.

You also get some sneaky core work when you do unilateral moves. “You’re forced to engage more muscles to keep yourself stabilized," Natalie Johnston, NYC-based certified personal trainer and run coach, tells SELF. While you may not feel that same burn you'd feel in an abs-specific workout, you're working all the stabilizer muscles in your core when you're trying to perform a move without losing your balance.

What’s more, single-leg exercises mimic many of the movements we do in everyday life. After all, we don't keep both feet on the ground at all times when we walk, run, or play many sports. “Doing this type of exercise will be good for your overall functionality because it closely resembles how you are actually moving your body in real life,” says Johnston.

While you can do a single-leg variation of most lower-body exercises, Johnston and Schromm’s go-to favorites include:
  • Single-leg deadlift: Builds power in your hamstrings, glutes, and calves. “Make sure that you don’t round your back as you lower down,” Johnston says. “Push your hips back and feel the stretch in your hamstring. Squeeze your glutes as you rise.”
  • Single-leg squat: Promotes hip stability and strength. Because this can be a tricky balancing act, start out with a bench or a foam mat beneath you. As you lower yourself down, “keep your pelvis steady and straight,” says Johnston.
  • Single-leg step-ups: Strengthens and stabilizes hips and glutes. “Drive up through your front heel as opposed to relying on your back leg,” says Schromm. You should feel the burn in your glutes, rather than your quads.

When doing these moves—and any single-leg exercise, for that matter—keep your posture upright and try not to lean to one side. “Keep your center of mass where it’s supposed to be,” says Johnston. “This will help with both form and stability.”

As for incorporating single-leg moves into your fitness routine, both trainers recommend starting slow, light, and steady.

“Make sure you master the form of the double-leg exercise before moving onto a single-leg stance,” says Johnston. This will help minimize your risk of injury and maximize the benefits of these exercises.

When you do feel ready for the single-leg version, begin by adding just a couple sets into your normal warm-up, says Schromm, who suggests a series of 10 single-leg deadlifts on each side followed by 10 single-leg step-ups on each side, performed with just your bodyweight. “This will help activate your stabilizer muscles before you dive into an intense workout,” she says.

When you master the moves with your bodyweight and feel ready for more, slowly incorporate the movements into your main workout, says Schromm. If you normally do 20 double-leg squats, for example, try 10 double-leg squats and 5 single-leg squats on each side.

It may take a while to find your balance and feel completely comfortable with single-leg movements, but keep at it. “Continually changing up the motion and angle of your movements will keep your body healthy, balanced, and efficient,” says Schromm. Adding some unilateral work into your routine is a great way to do just that.