Why One Leg Is Stronger Than the Other (and What to Do About It)

How to Test Which Leg Is Stronger

Costigan shares a few ways you can figure out which leg is stronger:

‌1. Starting from a standing position, pretend to fall and note with which leg you catch yourself.

‌2. Jump off of one leg and then the other to see how high you can jump. If you jump higher pushing off of your left leg, it’s likely to be stronger than your right.

‌3. Balance on one leg and then the other. The side that provides better balance is likely going to be stronger, and is often the dominant side.

Why Your Dominant Leg Might Be Stronger

It’s not a given that your “dominant leg” is the stronger one. But this is often the case due to factors like the following:

You Have One Dominant Hand

Often, hand dominance translates to leg dominance, Costigan says. If you’re right-handed, for example, you’ll usually defer to that hand for everyday tasks like holding a phone and picking up a bag. You might see that same pattern when you kick a ball or push something heavy — your right leg will move to the front for power.

And when you default to your dominant side for certain tasks over and over again, it’s inevitable for that side to build strength.

Your Activity Requires a Dominant Side

Certain activities will default to one side over another. This is often tied to hand dominance, but not always, Costigan says. When you do asymmetrical activities or have a history of doing them — you’re a former soccer or hockey player, for example — you’re more inclined to have more asymmetry and expose those dominance patterns, she says.

And while running is a symmetrical activity, ‌where‌ you run can affect strength, unequally. For instance, the angle the road is designed can play a role in which leg might be more dominant or stronger. Running on a track can also do this, if you run in the same direction over and over again, Costigan says.

“If you’re turning left [the traditional direction of track running] there is more weight on your left leg, and if your left leg is already dominant, that could cause additional stress,” she says.

You Have a History of Injury

If you’ve had a severe injury in the past — say, a torn left ACL 20 years ago — it likely still has some effect on you, Costigan says. Let’s say you were right-side dominant and the knee injury forced you to rely even more on your right side; that can create an issue.

Dominance vs. Strength

Although it’s not unheard of, it’s less common for your non-dominant leg to be stronger. In that case, it’s likely because your dominant leg is ‌overworked‌, Costigan says.

For example, if your right leg is dominant but your left leg is stronger, it could be because your right hip has more tightness. And that can inhibit increasing strength. Your non-dominant leg may also be stronger due to poor posture or form during exercise.

It may also be the case that the leg you identify as non-dominant is stronger for no reason other than genetics. “Dominance” itself operates on a spectrum, as shown by the phenomenon of ambidexterity. And remember, asymmetry is not necessarily a problem.

When Asymmetry Becomes a Problem

As Costigan points out, it’s natural to be somewhat asymmetrical. It only becomes a problem when there’s pain or compensation that can affect things like gait.

“Most people end up having an injury due to cumulative strain” she says. “Over time, you might slowly move in the direction of injury.”

Athletes who heavily favor one side are more likely to get an injury, Costigan says.

“That asymmetry gets exposed in athletes,” she says.

The best way to prevent asymmetry from becoming a problem is to take note of how you’re moving, Costigan says.

“Being an observer of yourself is key to preventing injury or addressing an issue,” she says. “‘I noticed I do this thing on my right side but not on my left.’”

That doesn't mean you have to figure out why — that’s what a physical therapist is for — but it makes you more aware of yourself.

“Loss of flexibility can be due to overuse on one side,” Costigan says. She notes that you’ll want to focus on how you move, especially with regard to flexibility, strength, and stability. “When there’s enough wrong with all three areas, you'll have pain.”

How to Strengthen Your Weaker Leg and Restore (Some) Symmetry

Not only are we asymmetrical beings, but everyday living has us moving on one leg at a time — for example, shifting from one leg to another while walking or running, says Abby Bales, a physical therapist and owner of Reform Physical Therapy in New York.

“We should practice doing that in our workouts,” Bales says.

Other exercises, like Pilates and yoga, use single-leg activities and opposite leg-to-arm movements.

“That works into the transverse and rotational planes of motion we use on a daily basis,” she says.

Bales shares three of her go-to moves to mimic some of the one-sided living we do, which can help strengthen the weaker side.

Bales demonstrates these moves using dumbbells, but you can use just your body weight to make the exercises easier. Or, you can increase the amount of weight used to make the moves harder.

1. Bulgarian Split Squat

1. Stand a few feet in front of a bench, box, or chair. Face away from it, and hold a dumbbell in each hand.
2. Reach your left foot back, and place the top of your foot flat on the surface. To help with balance, widen your base of support by moving your left foot a few inches to the left.
3. Lean your torso forward slightly, and bend your front knee to sink your hips toward the floor as low as you can comfortably go.
4. Your front-leg shin should be vertical or close to it, while your back knee should point down toward the floor. If either leg is out of place, move your front foot forward or backward until you’ve found the ideal positioning.
5. Push through the middle of your front foot to return to standing.
6. Repeat.
7. Complete all reps on one leg before switching to the other.

2. Single-Leg Deadlift

1. Stand on your right leg while holding a dumbbell in each hand, palms facing forward.
2. Keeping the right knee slightly bent, do the deadlift by bending at the hip. Extend your free leg behind you for balance or rest the top of your foot on a bench. During this movement, make sure your hips remain square.
3. Continue lowering the dumbbells until your upper body is parallel to the ground, or until you feel tension in the hamstring of your standing leg.
4. Keeping your back flat, return to the upright position.
5. Repeat on the opposite side.

3. Reverse Lunge

1. Stand with your feet about hip-width apart, arms at your sides, holding a dumbbell in each hand.
2. Step with your left leg 3 feet behind you and bend your knees until they form 90-degree angles. Your back knee should hover an inch above the ground, and your front thigh should be parallel to the ground (or as close as possible).
3. At the same time, bring your left arm up to form a 90-degree angle.
4. Keep most of your weight on the front leg as you press into your left heel and straighten your left leg.
5. Bring the left leg and arm back to the starting position and stand up.
6. Repeat the motion with the opposite leg and opposite arm.

The Takeaway

• It’s natural for one leg to be stronger than the other due to factors like hand dominance, specific activities (e.g., certain sports, running on a cambered road), or past injuries.
• While some asymmetry is fine, significant imbalances can lead to pain, compensation, or injury, especially in athletes.
• Incorporate unilateral exercises like Bulgarian split squats, single-leg deadlifts, and reverse lunges into your routine to strengthen your weaker leg and improve overall balance and stability.