Straight Leg Sit-Up

Muscles worked

Setup

1. Lie flat on your back on a mat with your legs fully extended and feet hip-width apart.
2. Press your heels firmly into the floor and engage your quadriceps to keep your legs locked straight.
3. Place your hands lightly behind your ears or cross them over your chest to avoid using momentum.

How to do it

1. Exhale as you tuck your chin slightly and begin peeling your spine off the floor one vertebra at a time.
2. Continue the movement until your torso is completely upright and perpendicular to the floor.
3. Inhale as you slowly reverse the movement, articulating your spine back down to the starting position with a controlled 3-second tempo.

Form checklist

• Keep your heels glued to the floor throughout the entire repetition.
• Avoid pulling on your neck; maintain a neutral cervical spine.
• Maintain a slight 'C-curve' in the spine during the ascent to maximize abdominal contraction.
• Ensure your legs remain straight by keeping your quads tensed.

Pro tips

• Focus on 'peeling' your spine off the floor rather than throwing your torso up to eliminate momentum.
• At the top of the movement, sit tall to briefly engage the deep hip flexors before beginning the slow descent.

Make it harder

• Hold a weight plate or dumbbell against your chest or extended overhead to increase the lever arm resistance.
• Slow down the eccentric (lowering) phase to 5-6 seconds to increase time under tension.

Frequently asked

What muscles does the straight leg sit-up work?

The straight leg sit-up primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.

What equipment do you need for the straight leg sit-up?

The straight leg sit-up requires no equipment — just your body weight.

Is the straight leg sit-up good for beginners?

Yes. The straight leg sit-up is a beginner-friendly movement and a strong foundation to build on.

Related exercises

• 3/4 Sit-UpBeginner · abs and obliques
• 45 Degree Bicycle Twisting CrunchIntermediate · abs and obliques
• 45 Degree Lean Back Alternate Knee RaiseBeginner · abs and obliques
• 45 Degrees Arms PlankIntermediate · abs, deltoids, obliques, and pectorals