preview for The Body Shop: Flex Benefits

Suffering from pain in your Achilles, hamstring, knee, or IT band (along the side of your leg)? Your hip flexors may be to blame. Weakness in the hip flexors—a group of muscles in the pelvic region and upper thighs that help drive up the knees and keep the pelvis and thighs aligned when running—can contribute to slower times, improper form, and, according to a recent review presented at the annual meeting of the American College of Sports Medicine, a host of lower-leg running injuries. "The body has the capacity to compensate for weak hip flexors, but the strategies to do that can lead to muscle imbalances and injury," says Gregory Holtzman, P.T., D.P.T., associate professor of physical therapy at Washington University and director of the university's Running Clinic, who recommends doing the following exercises three or four days a week.

Suffering from pain in your Achilles, hamstring, knee, or IT band along the side of your leg? Your
Boosts strength in both the hip flexors and the extensors, which prevent over-flexion and lower the knee for faster turnover
To Do: Stand with your feet shoulder-width apart. Take a step backward with your right foot and lower into a lunge. Push through your left heel to stand, driving your right knee up until it's parallel to the floor. Immediately lower back into a lunge. Do three sets of 10 reps on each side.

Single-Leg Stance
Engages the hip flexors using an isometric hold while also strengthening the standing leg's glutes, increasing stability and balance
To Do: While standing on your right leg, lift your left knee until your thigh is parallel to the floor. Hold for 10 seconds. Do three sets of 10 reps on each side.

Standing Knee Drive
Engages the hip flexors past a 90-degree angle to strengthen the muscles throughout their range of motion
To Do: Sit with good posture. Raise your right knee up toward your chest, not letting your thigh roll in or out. Pause, then slowly lower your knee to start. Do three sets of 10 reps on each side.

High Knees
Builds muscular endurance in the hip flexors to maintain proper form on long runs
To Do: While standing on your left leg, raise your right knee as high as you can, then repeat with your left leg after you return your right foot to the floor. Quickly continue alternating legs for 30 to 60 seconds. Do three sets.

IT Brand Stretches
K Aleisha Fetters
To Do: Loop a resistance band around a sturdy object. Stand facing away from that object with the band around your right ankle. Drive your right knee up until it's parallel to the floor. Slowly lower your knee back down. Do three sets of 10 reps on each side.

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To Do: Maintain the same position as in the IT Brand Stretches. This time, keeping your right leg straight, slowly flex your hip forward, pause for a second, then return to start. Do three sets of 10 reps on each side.

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Running Shoes & Gear
Running Shoes & Gear is a Chicago-based strength and conditioning specialist, contributing to publications including Time, Runner’s World, VICE, U.S. News & World Report, and STACK. She can usually be spotted in workout clothes and/or eating. Connect with her on Facebook or at kaleishafetters.com.