Your hamstrings are the muscles that stretch down the back of your thighs from your buttocks to your knees. As you run, your hamstrings help propel your legs forward. Yet, many runners have weak or tight hamstrings, and this leaves them prone to an array of injuries. If you want to protect your feet and legs when you're out pounding the pavement, make sure you're incorporating these hamstring stretches and strengthening exercises into your workouts.

Seated Knee Lifts

Perform this strengthening exercise on a yoga ball. Take a seat on the ball with your feet placed flat in front of you. Keep your shoulders back and forward, and look straight in front of you. Extend your arms forward with your palms facing upward to engage your core. Then, lift one leg off the ground, bending only at the hip. Hold this position, being careful not to roll off the ball, for about 10 seconds. Put your foot back on the ground, and repeat the move with the opposite leg. Try for 10 repetitions with each leg at first. Over time, you can build to holding each pose for 20–30 seconds.

Hamstring Presses

Start by laying flat on the ground with the back of your body facing downward. Rest your arms gently at your sides, and place an elastic band around your ankles. Hold the band loosely as you lift your feet off the ground. Then, tighten your grip on the band, and try to push your feet down against the resistance that the band poses. Keep pushing for about 10 seconds. Take a break, and then repeat for a total of 15–20 repetitions.

Seated Hamstring Stretch

When you're done strengthening your hamstrings, you should always finish with a stretch to ensure they're loose and supple. This stretch can be done on your yoga ball. Sit firmly on the ball with your feet flat in front of you and your arms held loosely at your sides. Straighten one leg as you bend forward at the waist, lowering your upper body toward the outstretched leg. Hold the position to the count of 5, and then switch legs. Stretch each side about 5 times or until you feel noticeably looser.

For most runners, doing these exercises two to three times a week is enough. Try adding them to the end of your workout on easy running days or do them on the days you take off from running. For more exercises and personalized information, visit a physical therapist, such as one at Clinic of Orthopaedic & Sports Physical Therapy.