Single Leg Crunch

What is a Single Leg Crunch?

The Single Leg Crunch is an abdominal exercise performed on a mat. The motion is a variant of a regular crunch, with one knee lifting toward your body at a time while you crunch your abdominal muscles. This movement works both the lower and upper abdominal muscles.

How do you do a Single Leg Crunch?

  • Step 1

    Start lying on your back with bent knees and your hands behind your head.

  • Step 2

    Lift your head, neck and shoulders off the ground by contracting your abdominal muscles. At the same time, lift one bent knee up until your thigh is perpendicular to the floor.

  • Step 3

    Extend your leg as you slowly lower your upper body back down, then repeat.

How do you modify a Single Leg Crunch?

  • Single Leg Crunch for Beginners

  • Single Leg Crunch for Weak Lower Back

What are the benefits of a Single Leg Crunch?

  • Core Strength

  • Leg Stretch

  • Flexibility

Expert opinion

You get a little bit of mobility work in this—meaning that as you’re alternating those legs up, you’re getting a lot more mobility work in your hamstrings as you pull up and try to keep your legs straight.
Paul Rahn,SWEAT in Chicago

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