3/4 Sit-Up
3/4 Sit-Up Exercise Description
The 3/4 Sit-up is a bodyweight trunk-flexion exercise performed from the floor, stopping short of a fully upright sit. It primarily targets the rectus abdominis, with assistance from the external and internal obliques and hip flexors. By limiting the range to about three-quarters of a full sit-up, the movement emphasizes controlled spinal flexion and abdominal bracing while reducing the need to pull the torso completely vertical.
This version teaches smooth segmental “curling” of the spine on the way up and down, helping you coordinate ribcage-to-pelvis movement without relying on momentum. It can be done anywhere without equipment and is suitable for most fitness levels when performed with proper neck position, steady breathing, and deliberate tempo. Keep the focus on curling the torso rather than swinging or yanking with the arms.
- Muscle Groups: Abs, Core, Waist
- Target Muscles: Rectus Abdominis
- Assisting Muscles: External Obliques, Iliacus, Internal Obliques, Psoas Major
- Stabilizing Muscles: Multifidus, Quadratus Lumborum, Transversus Abdominis
- Body Area: Upper Body
- Body Parts: Core, Torso
- Body Surface: Front
- Body Symmetry: Other
- Equipment: Bodyweight
- Exercise Patterns: Other
- Exercise Type: Strength
- Functional Grouping: Trunk Flexors
- Joint Involvement: Single-joint
- Muscle Location: Stomach
- Movement Direction: Vertical
- Muscle Position: Anterior
- Gender: Male
How To Do The 3/4 Sit-Up Exercise
‘- Lie supine with knees bent and feet flat, hip-width apart; arms crossed over chest or fingertips lightly at temples (don’t pull on your head).
– Set a light abdominal brace; gently tuck the chin so the neck stays neutral and your gaze is toward the ceiling.
– Exhale as you initiate by curling the head and shoulders off the floor, drawing the ribs toward the pelvis.
– Continue lifting the upper back in a smooth arc until you’re about three-quarters of the way to upright—stop before the torso becomes vertical.
– Keep elbows wide (if hands are at the head), lumbar region lightly flattened, and feet relaxed—not hooked—unless specifically directed.
– Pause briefly at the top while maintaining abdominal tension and a steady breath.
– Inhale as you lower with control, reversing the curl segment by segment until the shoulder blades touch down.
– Move slowly throughout; avoid jerking, using momentum, or letting the neck lead the motion.
3/4 Sit-Up Tips
‘- Set up lying on your back with knees bent, feet flat hip-width apart, and arms crossed over the chest or fingertips lightly at the temples.
– Keep your touch at the head light and elbows wide if your hands are at your temples; do not pull on your head.
– Lightly brace your abdominals and gently tuck your chin so the neck stays neutral and your gaze is toward the ceiling.
– Exhale as you initiate the movement by curling the head and shoulders off the floor, drawing the ribs toward the pelvis.
– Focus on a smooth, segmental curl of the spine rather than swinging the torso or yanking with the arms.
– Lift the upper body only until you are about three-quarters of the way to upright; stop before the torso becomes vertical.
– Maintain a lightly flattened lumbar region and keep the feet relaxed—not hooked—unless specifically directed otherwise.
– Pause briefly at the top position while maintaining abdominal tension and a steady breath.
– Inhale as you lower with control, reversing the curl segment by segment until the shoulder blades touch down.
– Move slowly throughout the exercise and avoid jerking, using momentum, or letting the neck lead the motion.
3/4 Sit-Up Beginner Introduction
The 3/4 Sit-up is a floor-based, bodyweight core movement that lifts the upper body partway toward sitting, then returns it back down in a smooth arc. Instead of coming all the way up, the motion typically finishes a little short of fully upright, so the effort centers more on bending through the midsection than on hauling the torso vertical. This style of sit-up highlights curling through the spine rather than swinging from the hips, creating a more deliberate, controlled feel.
The exercise mainly works the abs, with strong help from the side abs and hip flexors. Many people use it to practice steady bracing through the midsection while the back rounds and straightens in a flowing, segment-by-segment manner. Breathing is usually coordinated with the rise and descent, and the head and neck are aligned so the front of the body does the majority of the work. Because it relies only on bodyweight and a flat surface, it often fits easily into home routines and general core training for a wide range of experience levels.