Exercise / 437Animation available
Jackknife Sit-Up demonstration

Illustration by RepDB

Strength / Bodyweight

Jackknife Sit-Up

A full-body crunch performed from a floor-hover position, lifting both legs and torso simultaneously to touch hands to feet.

Equipment

Bodyweight

Experience

intermediate

Movement

compound

Primary musclesSecondary muscles

Obliques · Hip Flexors

Instructions

  1. 01

    Lie face-up on the floor with arms extended overhead and legs extended straight.

  2. 02

    Simultaneously lift the torso and the straight legs off the floor.

  3. 03

    Reach the hands up toward the feet as the feet rise — meet above the hips.

  4. 04

    Lower the torso and legs back to the floor under control.

  5. 05

    Repeat for the recommended number of repetitions.

Choose a load and range you can control. These instructions are general guidance, not a substitute for individual coaching.