GHD Sit-Up
What Is the GHD Sit-Up?
GHD Sit-Up is a compound exercise that primarily targets the core, especially the rectus abdominis, and also engages the hip flexors and the quadriceps. It is an advanced-level movement performed on a glute-ham developer: with the ankles locked between the foot rollers and the hips just behind the seat pad, you lower your torso back below parallel, then drive up to a tall seated position.
The exercise trains the trunk through a far longer range than a floor sit-up, from extension below horizontal to full flexion at the top. That makes it a demanding way to build trunk and hip flexor strength for gymnastics, lifting and field sports, and it is a staple of CrossFit workouts and competitions, where it usually appears in conditioning pieces or as accessory core work. Coaches often pair it with hip extension work such as the Hyperextension so the front and back of the trunk are trained in balance.
The hip flexors do much of the lifting, and a hard straightening of the knees at the bottom adds the rectus femoris to the drive. The abs work mainly to hold the trunk against the pull into extension as you lower, then curl it forward as you sit up, which is why first sessions leave the abs so sore. Stopping with the torso parallel to the floor shortens the lever and is the usual starting range, while lowering until the hands reach the floor is the full-range standard. Holding a medicine ball or plate at the chest adds load once full range is easy.
The GHD Sit-Up suits trained lifters and athletes who already control a Sit-Up and a Hollow Hold without strain. If you are not there yet, build up with the Decline Sit-Up and the V-Up, then start on the GHD with short sets that stop at parallel.
Muscles Worked
- Rectus Abdominis
- Primary
- Rectus Femoris
- High
- External Oblique
- Medium
- Sartorius
- Medium
- Tensor Fasciae Latae
- Medium
- Sternocleidomastoid
- Minimal
Instructions
- Adjust the footplate so that with your ankles locked between the foot rollers, your hips sit just past the back edge of the seat pad and your knees are slightly bent.
- Sit tall facing the foot rollers with your hands reaching toward your knees. Brace your abs and squeeze your glutes.
- Lower your torso backward under control, raising your arms overhead as you go and keeping your ribs down so your lower back does not sag over the pad.
- Continue until your torso is below parallel and your arms reach back toward the floor. If you are new to the exercise, stop with your torso parallel to the floor.
- Without pausing at the bottom, straighten your knees hard against the rollers and drive your torso back up.
- Swing your arms forward and keep rising until you are sitting tall again with your hands reaching toward your knees.
- Exhale as you sit up, inhale as you lower, and repeat for the planned reps.
Common Mistakes
Sitting on top of the pad
Resting the glutes on the seat pad instead of just behind it forces the lower back to arch over the pad as you lower.
Too much volume too soon
Jumping into high-rep sets without a build-up can cause days of severe soreness and, in some cases, exertional rhabdomyolysis.
Dropping into the bottom
Falling back instead of lowering under control lets the lower back sag into extension and skips the abs' braking work.
Skipping the knee kick
Starting the rise without straightening the knees leaves the hip flexors and lower back to haul the torso up on their own.
Going deeper than you can control
Reaching for the floor before you can return smoothly from parallel invites a stuck rep with the lower back fully arched.
Throwing the head forward
Whipping the chin toward the chest to start the rise strains the neck, so let the chest lead and keep the chin lightly tucked.
Injuries
GHD Sit-Up is a medium risk exercise when performed with proper technique. The places that usually complain are the lower back, the front of the hips and the neck. Back strain comes from sitting on top of the seat pad, dropping into the bottom and letting the lower back sag into extension, or starting the rise without the knee kick. Hip discomfort comes from the hip flexors hauling the torso up from a deep stretch, and neck strain from whipping the head forward to start each rep.
The bigger risk is volume. Lowering the torso below parallel loads the abdominal wall and hip flexors as they lengthen, the kind of work that causes the most muscle damage in tissue that is not used to it, and coaches have long linked high-rep GHD sets in newcomers to severe soreness and exertional rhabdomyolysis. A case report describes a 35-year-old woman with five years of CrossFit-style training who was hospitalized with rhabdomyolysis and severe abdominal pain after a two-day competition, which the authors linked to GHD work she was not accustomed to. In your first sessions, stop at parallel and do two or three sets of 5 reps, about 15 reps in total, then add only a few reps per week while recovery stays normal. Treat a return after a few weeks off as a new start.
To stay safe, set the footplate so your hips sit just past the back edge of the seat pad, squeeze your glutes and keep your ribs down as you lower, and start every rise by straightening your knees. To regress, stop at parallel or switch to the Decline Sit-Up or the floor Sit-Up. To progress, lower gradually toward the floor over several weeks, then hold a medicine ball or plate at your chest. If you have a history of disc problems or current low back pain, choose the Crunch or the Hollow Hold instead and check with a clinician before trying it.
Stop the set if you feel sharp or one-sided pain in the lower back, pain that travels into a leg, a pinch at the front of the hip, or neck pain that builds rep after rep. In the days after a session, muscle pain and swelling far beyond normal soreness, marked weakness, or dark tea- or cola-colored urine need prompt medical attention.
- Primary Focus
- Core
- Equipment
- Body weight
- Modality
- Strength
- Difficulty
- Advanced
Alternative Exercises
Other Names for the GHD Sit-Up
The GHD Sit-Up is also known as:
- Glute-Ham Developer Sit-Up
- Roman Chair Sit-Up
Frequently Asked Questions
- Q: Are GHD sit-ups safe for beginners?
Only with a gradual build-up. Start by stopping at parallel with two or three sets of 5 reps, about 15 in total, because high-rep sets on a first exposure can cause severe soreness and rhabdomyolysis.
- Q: How far back should I lower on a GHD sit-up?
Only as far as you can control and return from without the lower back sagging over the pad. Start with the torso parallel to the floor and lower further over several weeks; the full-range standard has the hands reaching back to touch the floor.
- Q: Do GHD sit-ups train the abs or just the hip flexors?
Both. The hip flexors do much of the lifting, while the abs work hard to stop the trunk from arching as you lower and to curl it forward as you sit up.
- Q: Why are my abs so sore after GHD sit-ups?
The lowering phase loads the abdominal wall in a long stretch that most people never train, and that unaccustomed lengthening work causes the most soreness. Normal soreness fades over a few days, but pain and swelling that keep building, marked weakness, or dark urine need prompt medical attention.
- Q: How is a GHD sit-up different from a regular sit-up?
A floor Sit-Up starts with the back on the ground, so the trunk only travels from flat to upright. On the GHD the torso lowers below horizontal, so the abs and hip flexors work from a stretched position over a much longer range, and straightening the knees helps drive the rise.