Crunch (exercise)

Crunches use the exerciser's own body weight to tone muscle and are recommended by some experts[like whom?

], despite negative research results[citation needed], as a low-cost exercise that can be performed at home.

[3] The biomechanics professor Stuart McGill was quoted in The New York Times Health blog as stating: An approved crunch begins with you lying down, one knee bent, and hands positioned beneath your lower back for support.

[4]Research has shown that both sit-ups and crunches are mediocre strength-building exercises and have injured many people.

This is said to eliminate any involvement by the hip flexors, and make the crunch an effective isolation exercise for the abdominals.