View this exercise on Fitain

Jack Knife

  • Intermediate
  • Body weight
  • Abdominals

Setup instructions

1) Lay on your back. Lift your legs up towards the ceiling so they're around a 45 degree angle. Now, raise your arms up so they're near parallel to the legs.

Perform instructions

1) Curl up by tightening the abs - aim to touch your toes.

2) Pause for a second at the top - your body should look like a 'V' at the endpoint. Now, gently lower yourself back to the floor.

3) Repeat.

Note: try keep your legs as straight as possible.

Health benefits

Muscular Endurance

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