How to do a crunch
A crunch is a floor exercise where you lie on your back and curl your shoulders up off the floor by shortening your abs. It targets the front of your core, the rectus abdominis.
- Core
- No equipment
- 15 reps
abdominal crunch, ab crunch, basic crunch
How to do it
- Lie on your back with your knees bent and your feet flat on the floor, hip-width apart.
- Place your fingertips lightly behind your ears, or cross your arms on your chest.
- Breathe out and curl your head, shoulders and upper back off the floor.
- Stop when your shoulder blades lift, with your lower back still on the floor.
- Lower slowly back down with control as you breathe in.
Form cues
- Lift with your abs, not your neck
- Breathe out on the way up
- Keep a fist of space under your chin
Muscles worked
Main: core
Also: obliques
Common mistakes
- Pulling the head forward with the hands. Fix: Keep your fingertips light, or cross your arms on your chest.
- Sitting all the way up. Fix: Curl up only until your shoulder blades leave the floor.
- Dropping back down fast. Fix: Take about two seconds to lower and keep tension in your abs.
Make it easier: Crunch with arms forward
Reach your hands toward your knees as you curl up, which makes the lift lighter.
Make it harder: Dead bug
Train your abs to control your lower back while your arms and legs move.
In a workout
Do 15 slow reps per set, for 2-3 sets, with a breath out on each lift.
Safety: If you have neck or lower back pain, keep the lift small and support your head, and stop if the pain gets worse.
Questions
What muscles do crunches work?
Mainly the rectus abdominis at the front of your core, with your obliques helping.
Why does my neck hurt during crunches?
You are likely pulling with your hands. Keep a fist of space under your chin and let your abs do the lift.
Are crunches or sit-ups better?
A crunch is a shorter move that keeps the work on your abs. A sit-up also uses your hip flexors.
