The three powerful muscles running down the back of your thigh are the semitendinosus, semimembranosus, and the bicep femoris. Together, these muscles are known as your hamstrings.

The hamstring is responsible for proper knee function, and is used all through your daily life in movements like walking, squatting, and walking up stairs. Whether you’re currently very active and want to improve strength, or if you’re just getting into exercise and want to tone up, these hamstring moves will get you started.

One of the main jobs of the hamstrings is bending your knee, so it’s not surprising that weak hamstrings are one of the biggest causes of knee injuries. According to the American Academy of Orthopaedic Surgeons, women are two to 10 times more likely to sustain a knee ligament injury, such as an anterior cruciate ligament (ACL) tear, than men.

One reason is because women tend to have stronger muscles in the front of the thigh (quadriceps) than in the back hamstring muscles. This imbalance can lead to injury. Weak hamstrings can also lead to a condition known as runner’s knee (patellofemoral pain syndrome). This painful condition is the most common running injury, resulting in inflammation and pain around the kneecap.

Of course, your body is an intricately connected system. Weak hamstring muscles impact a lot more than just your knees and hips. Weakened hamstrings have even been linked to everything from poor posture to lower back pain. A well-balanced body that includes strong hamstrings means that you can run fast, jump high, and do explosive moves like jump squats. Or just chase after your toddler without groaning!

Not to mention, strong hamstrings make for attractive legs. Well-trained hamstrings look sleek and sexy in cute shorts, a swishy skirt, or a stylish bathing suit!

To get the most out of your hamstring exercises, you’ll want to practice several different types of moves. Some hamstring moves come from the hip, and others originate from the knees. Don’t just do a single move over and over. Training the hamstring in a variety of ways will get better results, faster.

  1. Stand with your feet hip-width
    apart. Hold a barbell in front of your thighs with your arms straight.
  2. Hinge forward at the hips and
    stick your butt out while you keep your back straight.
  3. With a slight bend in your knees,
    bring the barbell towards the floor.
  4. Once the barbell reaches the
    point where your knees bend, or your body is parallel to the floor, use your
    hips to drive up back into the standing position.
  5. Do 2 or 3 sets of 10 to 15
    repetitions.

  1. Lie on the floor and place the
    heel of one foot on the edge of the bench so your leg forms a slighter wider
    than 90-degree angle.
  2. Extend the other leg straight up.
    Push into the heel on the bench and raise your hips up off the ground.
  3. Lower your hips down for a single
    rep.
  4. Do 2 or 3 sets of 10 to 15
    repetitions on each side.

Advanced: You can make this move harder by placing a barbell or a weighed plate on your hips.

  1. Stand in front of a bench, chair,
    or box that is 16 to 25 inches off the ground.
  2. Stand facing away from the box
    with a slightly wider stance and your toes slightly pointing out.
  3. Holding a weighed barbell in
    front of your chest and keeping your back firm, lower into a squat until your
    butt touches the surface. Return to standing. Do not let your knees go over the
    toes.
  4. One squat is a single rep. Do 10
    to 15 reps 2 or 3 times.

As you do this move, remember to keep your back straight and rotate from the hip.

  1. Holding a barbell or kettlebell
    in one hand, hinge forward at the hip, simultaneously extending the opposite
    leg straight behind you.
  2. Keep your back straight and lower
    your torso until your leg is parallel to the floor. If balance is an issue you
    can keep the toe of your back foot lightly touching the floor.
  3. Return to standing.
  4. Do 2 or 3 sets of 10 to 15
    repetitions on each side.

This machine-based move is highly effective because it completely isolates the hamstring. When completing this move, be sure to focus on controlling the movement and go as slowly as possible, as you don’t want to use inertia to move the weights as you curl your feet closer to your rear.

  1. This deadlift move takes pressure
    off your lower back by placing your feet further apart. Begin by taking an
    extremely wide stance.
  2. Lean down and grab the barbell
    (keep your hands directly below your shoulders and your feet should be wide,
    not your grip).
  3. Bending your knees, thrust your
    butt out as you lift up, driving down through your feet. Lean slightly back as
    you bring your hands and the barbell to hip-level.
  4. Pause, and then slowly return the
    barbell to the floor by bending at the hips.

Whether you’re an athlete looking to improve your fitness, or just want leaner, stronger legs, these dynamic exercises will help you tone and stretch your muscles. The muscles that make up your hamstring are a key part of knee and leg function. Improve the strength and flexibility of that muscle group and you’ll be well on your way to better overall fitness.

And hey, having gorgeous legs doesn’t hurt!