Crunch

AbsBodyweight

Crunches are a fundamental abdominal movement designed to isolate the rectus abdominis and build core control.

How to do it

1Lie flat on your back with knees bent and feet flat on the floor hip-width apart. Cross your arms over your chest or place fingertips lightly behind your head.

2Exhale and contract your abs to curl your head and shoulder blades off the floor while pressing your lower back down.

3Pause for a brief second at the top, squeezing your abdominal wall tightly.

4Inhale as you lower down under control without fully relaxing your abs at the bottom.

Common mistakes

Yanking on your neck with your hands — let your core do all the lifting.

Lifting your lower back off the floor, which shifts work off your abs.

Using momentum or swinging up instead of keeping a slow, controlled curl.

Losing abdominal engagement between reps by relaxing completely on the floor.

Breathing

Exhale as you curl up and flex your abs; inhale as you lower yourself back down.

Make it harder or easier

To scale down: Cross your hands over your chest or shorten the movement range.

To scale up: Place hands behind your head without pulling, add a pause at the peak contraction, or squeeze a small ball between your knees.

To add resistance: Hold a light weight plate or dumbbell against your chest.

This is general guidance, not a medical opinion. Listen to your body: if it hurts, stop. If you have an injury or a chronic condition, talk to a doctor first.