How to do Crunches
Reviewed by Jim Parker, CPT, B.A. Kinesiology
Workouts with Crunches
Target muscles worked
Instructions for Proper Form
Crunches are one of the most common exercises out there. It’s an easy to perform, bodyweight exercise that targets your abdominals. Crunches are very similar to Sit Ups, however, instead of raising your upper body all the way into a near sitting position, you only raise your shoulder blades off the ground. This is a great exercise for beginners looking to build core strength.
- Lie on your back with your knees bent and feet flat on the floor.
- Place your hands behind your head and keep your lower back against the floor throughout the exercise.
- Flex your abdomen to bring the bottom of your ribcage in towards your belly button while slightly tucking the chin until your upper back is off of the ground.
- Keep tension in your abdomen as you lower your shoulders back to the ground.
Tips & FAQs
Resting at the Bottom
Try to focus on keeping your core engaged even at the bottom of the motion. Even a momentary break at the bottom will make this exercise less effective. Focus on keeping some tension in your core as you lie back onto the ground.
Common Form Mistakes
Sitting Up Too Far
Crunches are designed so you only raise your shoulder blades, not your entire torso. While it isn’t ineffective or dangerous to raise your torso off the ground, it isn’t a crunch. Focus on contracting your abs to get just your shoulders elevated.
Sets & Reps Calculator
Average Crunches standards by male, female, gender, weight, age and height
Use this calculator to see Fitbod's possible first recommendations for you. This would be your starting line, based on more than 4.5 billion logged sets from 1.1 million users.
- beginner3sets9reps1 Set Max10reps
- intermediate4sets9reps11reps
- advanced4sets10reps12reps
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Alternatives & Variations to Crunches
1. Ab Crunch Machine
96.1 mSCORESWAPPED 20,533 TIMESAb Crunch Machine is a variation of Crunches performed with a machine. Unlike standard Crunches, the use of a machine gives you more control over your resistance. In addition, the machine will restrict your range of motion allowing you to focus more on exertion than stabilizing the movement.
- Intermediate
- Abs
- Ab Crunch Machine
2. Plank
92.8 mSCORESWAPPED 11,079 TIMESPlanks are one of the most common core exercises out there. This is a bodyweight exercise that is performed for time rather than reps. Planks don’t require any movement, instead they force you to place yourself in a position that requires you to engage your core, and maintain that muscle activation for the duration of the exercise. This is a great way to help build strength and stability in a way that will translate to a variety of other exercises, and your daily life.
3. Russian Twist
96.2 mSCORESWAPPED 8,949 TIMESRussian Twist is one of the more common core exercises. This exercise targets multiple muscles in your core, but the reason for including this exercise is usually to target your obliques. By raising your feet off the ground, engaging your core, and twisting to each side, you can better target this specific muscle in your core.
4. Leg Raise
96.5 mSCORESWAPPED 8,121 TIMESLeg Raise is a simple bodyweight core exercise that involves laying on the ground and suspending your legs in the air. While your core does play a significant role in raising your legs, the real benefit comes from controlling their descent back to the floor.
5. Bicycle Crunch
91.8 mSCORESWAPPED 7,420 TIMESBicycle Crunch is a more difficult version of a standard crunch. Instead of raising your torso off the ground for each rep, you keep your torso off the ground, and your core engaged. By cycling your legs, you add more instability to the movement, which leads to better core activation.
6. Sit Up
93.8 mSCORESWAPPED 7,059 TIMESSit Up is one of the most common exercises out there. It’s a bodyweight exercise that targets your core. Sit Ups are very similar to Crunches, however, rather than raising just your shoulder blades off the ground, you raise your entire upper body. This gives you a bit more range of motion than Crunches, however you’ll start to lose some tension in your core at the top of the movement.
7. Cable Crunch
88.8 mSCORESWAPPED 6,760 TIMESCable Crunch is a variation on the more standard Crunch. Unlike Crunches, this is a weighted exercise that does not have you laying on your back. Instead of using your bodyweight for resistance, you use a cable machine. This gives you more control over your resistance, as well as more control over the direction that resistance is coming from.
8. Vertical Knee Raise
92 mSCORESWAPPED 6,044 TIMESVertical Knee Raise is a bodyweight core exercise that involves suspending yourself, and then engaging your core to raise your knees towards your chest. By keeping your torso upright, and raising your knees, this exercise is a bit better for building functional, real world strength.
9. Decline Crunch
79.5 mSCORESWAPPED 5,261 TIMESDecline Crunch is a more challenging variation on the more standard crunch. Similar to a standard Crunch, this is a bodyweight core exercise. The use of a decline bench forces you to lay back further than you can on a flat surface. This helps improve muscle activation.
- Intermediate
- Abs
- Decline Bench
10. Leg Pull-In
94.9 mSCORESWAPPED 5,117 TIMESLeg Pull in is a bodyweight exercise that targets your core. By raising your legs off the ground, you’re already engaging your core. Additionally your core helps to pull your legs in towards your chest.