Performed on a glute-ham developer machine, GHD situps are often included in core-training programs to help athletes build strong abdominals and develop powerful, explosive hip closure, crucial to many sports. Unlike situps performed on the floor, GHD situps work and condition your abs through a full range of motion while recruiting the hip flexor muscles. Even though the GHD situp is designed for the more seasoned athlete, if you are a beginner, you can gradually work through a progression of steps with caution and the help of a trainer to master the exercise.
Setup and Starting Position
Set up the GHD machine to fit your stature. Most machines have an adjustable footplate with padded rollers to support your feet. This can usually be moved up and down and forward and backward. Adjust the height so the bottom rollers are aligned with the bottom of the padded seat.
Set the footplate distance from the seat. To do this, sit with your butt hanging just off the back edge of the seat and put your feet between the rollers. Adjust the footplate forward or back so you have a soft bend in your knees.
Sit tall with your spine in a neutral position and cross your hands across your chest or hold them behind your head. This is the starting position.
GHD Situp Progression
Learn the proper technique with the modified-situp version if you're new to GHD situps or you have weak core muscles. Otherwise, skip to the next step. Ask a fitness trainer to stand behind you to spot you. Have him hold his hands about 10 inches away from your shoulders. Tighten your abs, keep your back straight and lean back until the trainer stops your movement. Extend your knees and quickly return to the starting position with the spotter's help and repeat. Over time your core muscles will strengthen, and you'll be able to lean farther back and return to the starting position with minimal or no help from a spotter.
Perform "parallel" situps, a beginner version, once you've perfected the technique and have sufficient core strength. Assume the starting position and lower your upper body until you are parallel to the floor. Contract your quads, pop your knees down and sharply extend your legs to explode back up to the starting position. Lean forward, tap the rollers with your fingertips and repeat. Keep your abs tight throughout the exercise.
Advance to "beyond-parallel" situps only after you've mastered the beginner version. Assume the starting position, lower past horizontal and reach back with your hands. Stop when you're about to lose the neutral spine position, snap your knees down, extend your legs and explode back up to the starting position. Tap the rollers with your fingertips and repeat. Keep your ribs tucked throughout the exercise to avoid hyperextending your back.