No matter how many miles you run, there is one major factor limiting how long you can sustain that mileage: your strength. No, we’re not talking about your aerobic strength, but the strength of all of the muscles, ligaments, tendons, and bones that work together to allow you to run for an extended amount of time.

Due to its repetitive, high-impact nature, running puts an incredible amount of strain on your legs, hips, and core, which are particularly vulnerable to injury if not strengthened and stretched properly. Unfortunately, many runners—us included—have skipped post-run stretching or strength work to save time, and it’s come back to bite us (literally) in the butt. To save yourself from the heartbreak of being sidelined from running, it’s important to do your due diligence now. Because a good run is a pain-free run.

Why is strength-training important for runners?

Without question, running more is going to make you a better runner. So why waste time on non-running activities? You should think of stretching and strength training as long-term investments. You can get by without them, but once you start challenging yourself to go farther and faster than before, you’ll wish you had them to float you. At the same time, if you’re planning to run for life, building up strength and agility in your legs and core now will pay off handsomely in old age, when your muscle and bone mass begins to decline.

Saucony coach Tim Broe, who leads the Freedom Track Club, said that these are the most common weak spots for runners:

• This muscle group is made up of not only your rectus abdominis muscle (i.e., your six-pack abs), but also your oblique and transverse abs, which run along the side of your torso and wrap around your spine, respectively. All of these muscles work together to absorb shock and stabilize the hips.
• This region includes your pelvic bone, lower spine, and several muscles and connective tissues that keep the head of your femur securely positioned in your hip socket. The hips have the enormous task of lifting up your legs and supporting several times your body weight upon landing.
• The gluteal muscles are our built-in turbo boosters, giving power to our strides. Along with boosting your speed, your butt is also responsible for keeping your torso upright while driving your hips and quads forward.

Broe recommends strength training at least two times per week with exercises that target these essential body regions, and also foam rolling and stretching after every run. Here, Broe gives a few key strengthening moves to add to your repertoire.

Key core exercises for runners:

• Pot stirs with an exercise ball: While kneeling on the floor with an exercise ball in front of you, use your hands/forearms and roll the ball forward so you can place your elbows and hands on the ball with your feet on the floor. Next, lift your body up and hold this position. Try and maintain a straight spine as you move your forearms around the ball in a stirring motion. Do not allow your hips or pelvis on either side to drop. Repeat 20 times, then switch sides. Do two sets.
• Superman on exercise ball: Lie across the ball with your hips resting on the ball and your hands and toes touching the ground. Flex your shoulder and raise your arm while flexing your glute and raising the opposite leg, hold for one second, then switch legs. Repeat 20 times.
• Plank alternating arm and leg: While lying face down, lift your body up on your elbows and toes. Next, lift up one arm and opposite leg. Hold for a two-second count. Return to original position and then perform with the other arm and leg, and continue alternating for one minute. Try to maintain a straight spine.
• Marching bridge: While lying on your back, tighten your lower abdominals, squeeze your buttocks and then raise your buttocks off the floor/bed as creating a “bridge” with your body. While holding this position, lift one leg while maintaining a level pelvis. Hold for a two-second count, then set it back to the floor and then lift the opposite leg. Continue “marching” for one minute.
• Single arm plank: Begin in a plank position with your arms shoulder-width apart, pelvis tucked, and your neck and back flat. When stable, move one arm toward the center of the floor, then pick up the other arm and hold, maintaining good form. Hold for one minute on each side.
• Supine scissor kicks: While lying on your back, place your hands under your butt. Tilt your pelvis so that your lower back moves towards the floor and hold this position. Next, raise your legs up in the air and move them up and down in an alternate fluttering motion, never letting them touch the ground. Keep your lower spine pressed to the floor the entire time. Continue for 30 secon

Key hip exercises for runners:

• Single Leg Squat: Standing on one foot, lower your butt down to a 90-degree angle. Return to standing by driving the squatting leg down with the upper thigh and buttocks. The squatting leg should not rotate inward, and the foot shouldn’t turn outward. Repeat eight times on each leg.
• Lateral walks: With an elastic band around both ankles, walk to the side while keeping your feet spread apart. Keep your knees bent the entire time. Do three sets of 15-20 steps.
• Curtsies: Start with both feet on a step. Keeping one leg planted on the step, bend that knee and slowly lower down the opposite leg onto the floor. Make sure your knee does not go over your toes. Repeat 15 times on each leg.
• Hip abduction: While lying on your side, raise up your top leg. Keep your knee straight and point your toes as you raise and lower the leg. Do two sets of 20 on each side.

Strength for the win

Just like you wouldn’t dive right into high mileage as a new runner, you shouldn’t do all of these new exercises right off the bat. Start slow, with lower reps and just a few exercises, and gradually build up your strength training routine as your muscles adapt to the movements. If you feel any pain or discomfort while doing a certain movement, stop doing the movement or modify it in a way that works for you. Remember that soreness is normal, but pain is not. Listen to your body, and enjoy the fitness boost ahead!