One Perfect Move: The Bodyweight Step-Up Exercise for Bulletproof Legs

In between reps on the hip extension machine, leg press, Smith machine, and more, a leg day workout can easily turn into a two-hour sweat sesh—but building leg muscle doesn't have to be that complicated.

Enter: the bodyweight step-up. This move strengthens the outer glute and the inner knee, two key muscles that are part of your lower-body core. “Any muscle that crosses the hip joint is a core muscle,” says Michele Olson, Ph.D., clinical professor of sport science at Huntingdon College in Alabama and a Shape Brain Trust member. “These two are the most important in your lower core for balance and to prevent knee injuries.”

That last bit is particularly important, since women are more susceptible to knee ligament tears than men. In fact, women who play soccer are 2.8 times more likely to experience an ACL tear than men in the same sport, and that probability jumps to 3.5 for women in basketball, according to a study in the Journal of Orthopaedics. (If you do have a knee injury, try these strain-free workout moves.)

Despite squats being seen as the key to major #gains in the leg and booty department, the tried-and-true move might not be the best exercise out there. Olson tested this giant step-up against other bodyweight leg exercises—squat, lunge, and similar variations—to prove it was the best for these knee protectors, and surprise: It elicited twice the amount of muscle activity as the other moves did.

So what is a step-up exactly? As the name implies, you’ll step onto a sturdy chair or a weight bench that's about 20-inches tall with one leg, bringing the other knee up to hip height at the top. “Milk it,” says Olson, meaning go in slo-mo to increase the muscles’ time under tension, especially during the eccentric (lowering) part of the movement. "The more slowly you step up and then lower to place your suspended leg back on the floor, the more strength and sculpting you net,” she says. Remember to keep your core stable, too; throughout the move, brace yourself as if you're about to take a punch. Do 20 reps on each leg to be build muscle and help prevent future injuries.

How to Do the Bodyweight Step-Up Exercise

You'll need: One sturdy chair, weight bench, step, or box that's about 20 inches tall

A. Stand with feet hip-width apart, arms at sides, facing the front of a step. Place right foot on the step and tighten core to start.

B. Drive through right foot to step onto the top of the chair or bench, bring left knee up to hip height, keeping core engaged.

C. Very slowly lower the left leg back to the floor to return to start.

Do 20 reps on one leg. Switch sides; repeat.