Open Leg Crunch Tutorial
The Open Leg Crunch is a bodyweight ab exercise that combines a traditional crunch with controlled leg opening. It targets the upper abs while also challenging hip control and coordination.
This move is ideal for beginners who want to learn how to engage their core without equipment, but it still requires focus and control. You lift the upper body as the legs open into a wide V, reaching the hands forward between them.
Focus on slow, controlled movement, keeping your lower back gently pressed into the floor and your neck relaxed. This exercise works best when done with intention rather than speed.
Benefits
- Strengthens upper abdominal muscles
- Improves core control and coordination
- Teaches proper crunch technique
- Engages hips without stressing the joints
- No equipment needed
- Easy to adjust intensity
- Good foundation for harder ab moves
Setup & Starting Position
Lie flat on your back on an exercise mat or comfortable floor surface. Extend both legs straight up toward the ceiling so they are vertical, knees fully extended but not locked. Your feet should be relaxed, toes pointing slightly upward.
Bend your arms and bring your hands together above your chest, elbows relaxed and pointing outward. Let the back of your head rest on the floor with your neck long and relaxed.
Before starting, gently draw your belly button inward and press your lower back lightly into the floor. This sets your core and protects your spine.
Setup tip: If your lower back arches off the floor, slightly lower your legs or bend the knees until you can maintain contact.
How To Do Open leg crunch (Step-by-step)
- Start lying on your back with legs straight and raised vertically.
- Hands are together above the chest, arms bent and relaxed.
- Inhale and brace your core gently.
- Exhale as you lift your head, neck, and shoulders off the floor.
- At the same time, open your legs outward into a wide V shape.
- Reach your hands forward between your legs as you crunch up.
- Pause briefly at the top while keeping tension in your abs.
- Inhale and slowly return your upper body to the floor.
- Bring your legs back together to the starting position.
- Reset and repeat for the next rep.
Form Cues
- Keep lower back pressed down
- Move slow and controlled
- Neck stays relaxed
- Open legs only as wide as you can control
- Crunch upward, not forward with arms
- Exhale on the lift
Breathing & Bracing
Proper breathing helps you get more out of the Open Leg Crunch and protects your lower back. Begin each rep with a gentle inhale through your nose while bracing your core.
As you crunch up and open your legs, exhale slowly through your mouth. Think about tightening your abs as if you are zipping them up from your pelvis to your ribs.
Avoid holding your breath. Your rib cage should stay down and connected to your core, not flaring upward. Keep the movement smooth and controlled.
A simple rhythm to repeat is: inhale at the bottom, exhale as you crunch and open, then inhale again as you return.
Common Mistakes
- Pulling on the neck, fix it by keeping hands away from the head.
- Arching the lower back, fix it by lowering the legs slightly.
- Using momentum, fix it by slowing down each rep.
- Opening legs too wide, fix it by reducing range of motion.
- Holding breath, fix it by exhaling on the crunch.
- Rushing reps, fix it by counting the tempo.
How It Should Feel
Quick Self-Check:
You should feel a strong but controlled contraction in your upper abs as you crunch upward. The movement should feel smooth, not jerky.
Good signs:
- Burning sensation in the abs
- Stable lower back against the floor
- Controlled leg movement
Warning signs:
- Sharp pain in the lower back or neck, stop immediately
- Hip strain from opening too wide
If you feel it mostly in your neck, relax your shoulders and focus on lifting with your ribs. If you feel it in your lower back, reduce leg height or bend the knees slightly.
Alternative Names
Open V Crunch
Variations
Easier
- Bent Knee Open Crunch, keep knees bent while opening legs to reduce load.
- Partial Range Open Crunch, crunch halfway up instead of full height.
Harder
- Slow Tempo Open Leg Crunch, take 3 seconds up and 3 seconds down.
- Pause Open Leg Crunch, hold the top crunch position for 2 to 3 seconds.
Sample Workout
Beginner Core Workout:
- Open Leg Crunch, 3 sets of 10 to 12 reps
- Dead Bug, 3 sets of 8 reps per side
- High Plank Hold, 3 sets of 20 to 30 seconds
Rest 45 to 60 seconds between sets. Focus on slow, controlled reps rather than speed.
Progression Plan
Week 1: Perform 2 to 3 sets of 8 to 10 reps. Focus on learning the technique, keeping your lower back flat and moving slowly. Rest 60 seconds between sets.
Week 2: Increase to 10 to 12 reps per set. Add a brief pause of 1 second at the top of each crunch to improve control.
Week 3: Keep reps the same but slow the tempo, taking 3 seconds up and 3 seconds down. Reduce rest to 45 seconds.
Week 4: Progress to a pause or slow tempo advanced variation. If form breaks down, repeat the previous week.
Only progress when you can complete all reps with control and no lower back discomfort.
FAQ
How many reps should I do?
Most beginners start with 8 to 12 controlled reps per set.
Should my legs be perfectly straight?
Yes, but do not lock the knees. Slight softness is fine.
Is this safe for lower back?
Yes, if your lower back stays pressed into the floor throughout.
Can I do this every day?
You can, but allow rest if your abs feel overly sore.
Why do my hips feel tired?
The hip flexors assist in holding the legs up, which is normal.
Summary
The Open Leg Crunch is a simple yet effective way to strengthen your abs while learning proper core control. By combining a crunch with leg movement, it teaches coordination and body awareness.
Keep your movements slow, your breathing steady, and your lower back supported. As you build strength, you can progress with tempo and pauses for greater challenge.
Practice consistently, focus on form, and this exercise can become a solid part of your core training routine.
Get Defined Abs in 30 Days
This exercise is part of our complete 30-day ab program. Download the app for structured daily workouts and track your progress.