Lying Crunch (Straight Legs)
Lying Crunch (Straight Legs) Exercise Description
The lying crunch (straight legs) is a controlled spinal-flexion exercise that targets the rectus abdominis, with the obliques and transverse abdominis assisting for trunk stability. Keeping the legs straight on the floor minimizes lower-body movement so you can focus on curling the ribcage toward the pelvis rather than bending at the hips. The range of motion is small—just enough to lift the head, shoulders, and shoulder blades off the floor—prioritizing abdominal tension over height. A gentle posterior pelvic tilt (flattening the low back toward the mat) reduces hip flexor contribution compared with sit-ups and helps protect neutral alignment. Proper neck position, smooth breathing, and deliberate tempo keep the workload on the abdominal wall while avoiding momentum or strain.
- Muscle Groups: Abs, Core, Waist
- Target Muscles: Rectus Abdominis
- Assisting Muscles: External Obliques, Internal Obliques
- Stabilizing Muscles: 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: Female
How To Do The Lying Crunch (Straight Legs) Exercise
‘- Lie supine on a mat with legs extended together, heels on the floor, toes relaxed.
– Cross arms over the chest or lightly support the base of the skull with fingertips; keep elbows wide and avoid pulling.
– Set a gentle posterior pelvic tilt so the low back is lightly in contact with the floor.
– Brace the trunk; keep the neck neutral with a small chin tuck and eyes toward the ceiling.
– Exhale and curl the torso, bringing the ribcage toward the pelvis; lift head and shoulders until the shoulder blades just clear the floor.
– Pause briefly while maintaining abdominal tension; keep legs relaxed and still.
– Inhale and lower slowly, returning the shoulder blades to the floor without losing the pelvic tilt.
– Keep movement smooth—no bouncing, yanking the head, or swinging the arms.
– Maintain even breathing; avoid holding your breath or arching the low back.
Lying Crunch (Straight Legs) Tips
‘- Keep your legs straight, heels on the floor, and let the toes relax so the lower body stays quiet.
– Set a gentle posterior pelvic tilt so your low back stays lightly in contact with the floor.
– Think about curling your ribcage toward your pelvis instead of trying to sit all the way up.
– Keep your neck neutral with a small chin tuck and eyes toward the ceiling to avoid strain.
– If your hands are behind your head, keep the elbows wide and avoid pulling on your head.
– Exhale as you curl up, lifting the head and shoulders only until the shoulder blades just clear the floor.
– Pause briefly at the top and keep the abs tight while the legs stay relaxed and still.
– Inhale as you lower slowly, returning the shoulder blades to the floor without losing the pelvic tilt.
– Move smoothly—avoid bouncing, swinging the arms, or using momentum.
– Maintain even breathing throughout and avoid holding your breath or arching your low back.
Lying Crunch (Straight Legs) Beginner Introduction
The lying crunch (straight legs) is a slow, precision-based core exercise built around curling the upper body rather than swinging it. The movement highlights the abs, with support from the side abs and deep abs to steady the midsection. With the legs long and relaxed on the ground, the lower body stays quiet while the chest gently rolls toward the hips through a short arc. The lower back remains close to the mat, which shifts effort away from the front of the hips compared with traditional sit-ups.
Only the top part of the spine leaves the floor, so the emphasis stays on constant tension instead of chasing height. The neck rests in a natural position, with the head supported either by crossed arms or light fingertips. Breathing stays smooth and deliberate, matching the controlled rise and return of the torso. This combination of small movement, calm tempo, and stable posture encourages strong abdominal engagement without relying on momentum.