Exercise guide
Crunch Floor
- Beginner
- Isolation
- Rep-based
- Waist
The floor crunch is a foundational isolation exercise that targets the rectus abdominis by using spinal flexion to build core strength and definition. It effectively engages the upper abs while minimizing hip flexor involvement when performed with proper technique.
Reviewed by the Crucible Fit team · Updated June 2026
Muscles worked
Setup
- Lie flat on your back on a mat with your knees bent and feet flat on the floor, hip-width apart.
- Place your fingertips lightly behind your ears or cross your arms over your chest.
- Tuck your chin slightly to maintain a neutral neck and engage your deep core.
How to do it
- Exhale and contract your abdominals to lift your shoulder blades 2-3 inches off the floor, curling your ribs toward your pelvis.
- Hold the peak contraction for one second while squeezing your abs.
- Inhale as you slowly lower your upper back to the floor, maintaining tension throughout the descent.
- Perform the movement with a controlled 2-1-2 tempo (2 seconds up, 1 second hold, 2 seconds down).
Form checklist
- Keep your lower back pressed firmly into the floor at all times.
- Avoid pulling on your head or neck; use your abs to lift your torso.
- Keep your elbows wide and out of your peripheral vision.
- Focus on the 'ribs-to-hips' shortening rather than just lifting your head.
Pro tips
- Visualize peeling your spine off the floor one vertebra at a time to maximize abdominal engagement.
- Exhale all the air from your lungs at the top of the movement to achieve a deeper contraction.
Make it harder
- Lift your feet off the floor and hold your legs in a 90-degree tabletop position.
- Reach your arms straight overhead to increase the lever length and resistance.
Frequently asked
- What muscles does the crunch floor work?
- The crunch floor primarily targets the abs and obliques, and also works the erector spinae as secondary muscles.
- What equipment do you need for the crunch floor?
- The crunch floor requires no equipment — just your body weight.
- Is the crunch floor good for beginners?
- Yes. The crunch floor is a beginner-friendly movement and a strong foundation to build on.