3/4 Sit-Up

Learn how to do the 3/4 sit-up with proper form to build stronger abs and improve hip flexor endurance.

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How to perform

Lie flat on your back with your knees bent and feet flat on the floor, about hip-width apart. Place your hands behind your head with your elbows pointing outward, or cross them over your chest for a lighter version. Exhale and slowly curl your upper body off the ground, tucking your chin slightly and lifting until your torso reaches about a 45-degree angle. Pause briefly at the top, feeling your abs contract, then inhale and lower your upper body slowly back to the floor. Repeat for the desired number of reps, keeping the movement smooth and free of momentum.

Muscles worked

The 3/4 sit-up is a spinal-flexion movement that works your rectus abdominis through a long, deliberate range of motion. As you rise past the mid point, your hip flexors take on a bigger share of the load, while the lower back works to control the lowering phase.

• Abs — curl the torso up against gravity
• Hip flexors — assist as the torso approaches the top
• Lower back — slows and controls the descent

Make it easier

Cross your arms over your chest instead of holding your head, or anchor your feet under a couch so the hips stay down. Cutting the range to a shallow curl also reduces the load.

Make it harder

Hold a weight plate on your chest, pause for two seconds at the top of every rep, or lower with a three-second count. Keeping your feet unanchored while doing the full range adds a serious balance demand.

Common mistakes

• Mistake: Pulling on your neck to yank yourself up. Fix: keep your hands light and think of curling with your abs; your arms are just support.
• Mistake: Jerking up with momentum. Fix: rise slowly and pause at the top so every rep comes from muscle, not swing.
• Mistake: Dropping fast and slamming onto the floor. Fix: control the descent for at least two seconds.