Crunch
Muscles worked
Instructions
- 1Lie flat on your back with your feet flat on the ground, or resting on a bench with your knees bent at a 90 degree angle. If you are resting your feet on a bench, place them three to four inches apart and point your toes inward so they touch.
- 2Now place your hands lightly on either side of your head keeping your elbows in. Tip: Don't lock your fingers behind your head.
- 3While pushing the small of your back down in the floor to better isolate your abdominal muscles, begin to roll your shoulders off the floor.
- 4Continue to push down as hard as you can with your lower back as you contract your abdominals and exhale. Your shoulders should come up off the floor only about four inches, and your lower back should remain on the floor. At the top of the movement, contract your abdominals hard and keep the contraction for a second. Tip: Focus on slow, controlled movement - don't cheat yourself by using momentum.
- 5After the one second contraction, begin to come down slowly again to the starting position as you inhale.
- 6Repeat for the recommended amount of repetitions.
About Crunch
The crunch is the foundational ab movement: lying on your back with knees bent, you lift the shoulders off the floor by curling the upper trunk, then lower under control. It isolates the upper portion of the rectus abdominis over a short range, without recruiting the hip flexors the way a sit-up does. It is one of the best entry points for a beginner: no equipment, minimal lower-back risk and simple technique to master. Once the movement is clean, you can move on to heavier variations such as the cable or decline crunch.
check_circleBenefits
- check_circleEfficiently isolates the upper rectus abdominis
- check_circleSimple to master and requires no equipment
- check_circleLower-back stress stays minimal compared with a full sit-up
lightbulbExecution tips
- lightbulbLift only the shoulder blades; the lower back stays on the floor
- lightbulbKeep a small gap under the chin instead of jamming it to the chest
- lightbulbExhale on the way up and squeeze the abs hard at the top
- lightbulbLower slowly without fully releasing the tension
warningCommon mistakes
- warningPulling on the neck with the hands behind the head
- warningLifting the whole torso like a sit-up instead of curling
- warningUsing momentum and bouncing off the floor between reps
- warningLifting the lower back and recruiting the hip flexors
helpFrequently asked questions
How many reps per set?expand_more
15 to 25 slow reps is plenty; add weight on the chest if it becomes too easy.
Do crunches give you a flat stomach?expand_more
They strengthen the abs, but a visibly flat stomach depends mostly on your body-fat level.
How many times a week should I do crunches?expand_more
Two to three sessions a week are enough. Like any muscle, the abs need to recover: training them every day does not speed up results.
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