Obstacle races have gotten incredibly popular over the last few years, for obvious reasons: They break up the monotony of running a 5k (or more) with cool challenges, giving distracted and bored brains something to do instead of count steps. But with what’s demanded of your body in these races, you’re open to a new set of potential injuries — most commonly, pulled hamstrings.

A hamstring pull often occurs when attempting to extend your leg with a lot of force, like attempting to jump over water. You’re especially susceptible to a hamstring pull if you have weak and restricted hamstrings. They can become overworked when the body places an increased demand on this muscle group instead of utilizing other important muscles like the glutes, lats, calves, and core to achieve posterior chain (the back side of the body) stability. The body needs to distribute the workload across multiple muscle groups for efficient output. At a race event, overcompensation leading to a pulled hamstring is most often seen at the end of the course.

To save yourself the pain of a pull, it’s vital that you target your posterior chain during a proper warm-up. Just like a race car needs to let its engine rev before a race, your body needs to be warmed before you hoist a tire, climb a wall, or crawl through the mud. A proper warm-up helps increase the elasticity of your muscles, floods the muscles with blood, raises the temperature of the muscles, and releases adrenaline and other chemicals you will need for the race.

Here’s how to rev that engine.

Curtsy Lunges

  • Stand with feet shoulder-width apart.
  • Step back and cross the rear foot behind the front foot.
  • Bend both knees to 90 degrees, front knee directly over the ankle. Weight should be through the heel of the front foot.
  • Hold stance and hinge from hips and reach forward. Repeat.

Hollow Body Hold

  • Lie on your back with you hips and knees at 90-degree angles. Keep back flat on the ground to ensure the low back doesn’t curve.
  • Raise arms slightly off the ground with the elbows straight, palms facing down. Pretend to reach down toward your feet.
  • Hold this position, using only your abs, until fatigue.

Ball Over Head

  • Lie on your back and keep your back flat on the ground, knees bent at 90-degree angles, with your feet flat on the ground.
  • Hold a medicine ball with arms locked out, directly over chest.
  • Punch up toward ceiling so shoulders are off the ground, then slowly bring arms overhead as far as you’re able.
  • Bring the ball slowly back towards your knees. Repeat.

Good Mornings

  • Stand with feet shoulder-width apart, a slight bend in the knees, feet pointing forward, and weight through the heels.
  • Chin should be tucked in to keep your spine straight through the movement.
  • With a flat back, bend forward by hinging from your hips and move your torso towards the floor.
  • After getting a good stretch in your hamstrings, return to standing. Repeat.

Sumo Lat Squats

  • Fasten a resistance band to an anchor, like the post of a squat rack, at about mid-torso height.
  • Grab the resistance band with both hands. Make sure elbows are bent at 90-degree angles, and squeeze your shoulder blades back and down. There should be some light resistance in the band.
  • With feet shoulder-width apart and your weight in your heels, squat back, like you’re sitting in a chair, letting the resistance band keep you upright.
  • Get as low as you can, then push back up through your heels, maintaining upright posture. Repeat.

Single-Leg Bridge

  • Lie on the ground, feet and back flat, with knees bent.
  • Lift one leg so it’s perpendicular to the ground.
  • Pushing through the heel, lift your hips up off the ground. Press hips up and down. Repeat on the opposite side.

Bird Dog

  • Begin on hands and knees. Squeeze glutes, draw stomach in, pull your shoulder blades down, and keep head in line with spine.
  • Holding the position, lift the right arm and left leg so that each is straight and hold for three seconds.
  • Lower back down, then perform with the left arm and right leg. Repeat.