Crunches
The basic ab exercise: you round your upper back to bring your ribs toward your hips, either lying on the floor, kneeling at a cable or seated in an ab crunch machine.
Equipment
- Primary muscles
- Abs
- Secondary
- Lower abs
- Difficulty
- Beginner
- Logged as
- Weight × reps
- Primary muscles
- Abs, Lower abs
- Secondary
- Obliques
- Difficulty
- Beginner
- Logged as
- Weight × reps
- Primary muscles
- Abs
- Secondary
- Lower abs, Obliques
- Difficulty
- Beginner
- Logged as
- Reps
Why do it
Crunches train your abs through a short range of spinal flexion, which makes them easy to learn and easy to load. The floor version needs nothing and suits beginners. The kneeling cable crunch lets you add weight in small steps, so it's the pick once floor reps get high, and the ab crunch machine gives the most guided path, which helps if you struggle to feel your abs. Whichever you choose, the rep is short, and unlike a sit-up, your hips stay put and your hip flexors stay mostly out of it.
How to do it (Machine)
Set the seat so the chest pad sits against your upper chest and your back rests on the backrest.
Grip the handles, or cross your arms over the pad if the machine has no handles, with your feet planted.
Crunch forward by rounding your upper back and bringing your ribs toward your hips.
Return slowly under control. The movement is short; it's spinal flexion, not a sit-up, so don't chase extra range by pushing with your legs.
Attach a rope to the high pulley and kneel in front of the machine, facing the stack.
Hold the rope ends next to your head and set your hips so they stay in one place during the set.
Crunch down by rounding your upper back and bringing your elbows toward your thighs.
Return slowly under control. The movement is spinal flexion, so if your hips are hinging you're doing a pulldown with your abs along for the ride.
Lie on your back with your knees bent and feet flat, arms crossed over your chest or fingertips behind your ears.
Curl your shoulders off the floor by bringing your ribs toward your pelvis.
Hold the top for a moment.
Lower slowly. Your lower back stays on the floor throughout; if you're coming all the way up, that's a sit-up, not a crunch.
Common mistakes
Turning it into a sit-up
Coming all the way up on the floor shifts the work to your hip flexors. Stop once your shoulder blades are off the floor and your ribs have curled toward your hips.
Hinging at the hips on the cable
If your hips move back and forth, the cable crunch becomes a pulldown with your abs along for the ride. Lock your hips in place and only round your spine.
Pushing with your legs on the machine
Driving through your feet to move the pad adds range that isn't coming from your abs. Keep your legs relaxed and let the curl of your upper back move the weight.
Yanking on your neck
Pulling your head forward with your hands does little for your abs. Keep your fingertips light behind your ears or cross your arms over your chest.
Sets, reps and progression
How many sets you do and how close to failure you take them depend on your goal and your week, not on the exercise. These guides cover it:
Alternatives that train the same thing
Same movement, a different angle or piece of equipment.
