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  5. Core & Abs
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  7. Glute Ham Developer Full Sit Up

Exercise guide

Glute Ham Developer Full Sit Up

  • Intermediate
  • Compound
  • Rep-based
  • Upper legs
  • Waist

The GHD Sit Up is an advanced core exercise that utilizes an extreme range of motion to challenge the rectus abdominis and hip flexors under high tension. It is highly effective for developing explosive midline stability and anterior chain power.

Reviewed by the Crucible Fit team · Updated June 2026

Watch the Glute Ham Developer Full Sit Up demonstrationVideo and instructions for every movement are in the Crucible Fit app.

Muscles worked

Primary

  • Glutes
  • Hamstrings

Secondary

  • Abs
  • Obliques
  • Quadriceps

Equipment

  • Body weight

Setup

  1. Adjust the GHD footplate so that your hips are positioned slightly behind the center of the main pad.
  2. Secure your feet firmly between the ankle rollers with your heels pressed against the footplate.
  3. Sit upright with your knees slightly bent and your torso vertical.
  4. Cross your arms over your chest or hold them near your temples.

How to do it

  1. Inhale and slowly lower your torso backward until your body is parallel to the floor or your hands touch the ground.
  2. Exhale and explosively contract your quadriceps to straighten your legs while simultaneously crunching your abs.
  3. Return to the vertical seated position by pulling your torso upward in one fluid motion.
  4. Maintain a controlled 2-0-X-1 tempo: two seconds on the way down and an explosive ascent.

Form checklist

  • Ensure your hips stay off the pad to allow the pelvis to rotate freely.
  • Avoid excessive arching of the lumbar spine at the bottom of the movement.
  • Keep your neck neutral and avoid leading the movement with your chin.
  • Aggressively extend your knees to initiate the upward phase of the sit-up.

Pro tips

  • Focus on the 'knee snap'—the rapid straightening of your legs is the primary driver that helps your torso overcome gravity from the bottom position.
  • Visualize your abs acting as a secondary stabilizer to the hip flexors to protect your spine during the high-velocity ascent.

Make it harder

  • Hold a medicine ball or weight plate at chest level or extended overhead throughout the movement.
  • Slow down the eccentric (lowering) phase to 4-5 seconds to increase time under tension.

Frequently asked

What muscles does the glute ham developer full sit up work?
The glute ham developer full sit up primarily targets the glutes and hamstrings, and also works the abs, obliques, and quadriceps as secondary muscles.
What equipment do you need for the glute ham developer full sit up?
The glute ham developer full sit up requires no equipment — just your body weight.
Is the glute ham developer full sit up good for beginners?
The glute ham developer full sit up is rated intermediate. Build a base with simpler variations first, then progress to it with light load and strict form.

Related exercises

  • Alternating Hamstring Curl JackIntermediate · abs, glutes, hamstrings, and quadriceps
  • Alternating Hamstring Curl Overhead ClapIntermediate · abs, glutes, and hamstrings
  • Around The World Superman HoldIntermediate · erector spinae, glutes, hamstrings, lats, and trapezius
  • Back Leg Lift JackBeginner · abs, glutes, hamstrings, and obliques

Train it with Crucible Fit.

Every movement in this library is in the app with video and instructions, ready for your own sessions on the days between Crucibles. Your first Crucible is on us.

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