The knee crunch is a bodyweight exercise that helps build core strength and targets your abdominal muscles. Knee crunches add a challenging twist to a range of motion similar to sit-ups and basic crunches. To do knee crunches, lie flat on your back with your hands behind your head, knees bent, and feet on the floor. Lift your knees so that they form a 90-degree angle, then bring your head toward your knees by crunching your stomach muscles. Return to the starting position before repeating. 

Once you've mastered knee crunches, try knee crunch alternatives such as [reverse crunches](https://www.masterclass.com/articles/reverse-crunch-guide), knee-ups, bicycle crunches, and [mountain climbers](https://www.masterclass.com/articles/mountain-climber-exercise).
There are several notable benefits to regularly practicing knee crunches.

1. __Knee crunches can help you achieve six-pack abs__. The primary muscle targeted by knee crunches is your rectus abdominis, the core muscles responsible for the six-pack. 
2. __Knee crunches build lower-body strength__. In addition to targeting your core, knee crunches build strength in your hip flexors, lower back, and lower abs. 
3. __Knee crunches are a convenient home workout__. Knee crunches are a bodyweight exercise that do not require you to have any special exercise equipment, making them easy to practice at home.
For knee crunches, begin by performing 2–3 sets of 10–15 repetitions. Choose your sets and repetitions based on your ability to maintain good technique throughout.

1. Lie face-up on an exercise mat with your knees bent and your feet on the floor. Place both of your hands on the back of your head without interlocking your fingers. Your ribs should be down and your pelvis should be slightly tucked. 
2. Engage your core. Your chin should remain tucked throughout the movement, as if you were holding an egg under your chin.
3. Lift your knees toward your chest so your knees are directly over your hips. All repetitions should begin from this starting position.
4. Begin the upward movement by squeezing your abs. Curl your shoulders off the floor while squeezing your abs. Pause at the top of the movement.
5. Slowly lower to the starting position while maintaining tension on your abs.
6. Repeat for your desired number of repetitions.
If you have a previous or pre-existing health condition, consult your physician before beginning an exercise program. Proper exercise technique is essential to ensure the safety and effectiveness of an exercise program, but you may need to modify each exercise to attain optimal results based on your individual needs. Always select a weight that allows you to have full control of your body throughout the movement. When performing any exercise, pay close attention to your body, and stop immediately if you note pain or discomfort.

To see continual progress and build body strength, incorporate proper warm-ups, rest, and nutrition into your exercise program. Your results will ultimately be based on your ability to adequately recover from your workouts. Rest for 24 to 48 hours before training the same muscle groups to allow sufficient recovery.
Throw on some athleisure, fire up a [MasterClass Annual Membership](https://www.masterclass.com), and get ready to sweat it out with exclusive instructional videos from Nike Master Trainer and *GQ* fitness specialist Joe Holder. Want to improve your cardiovascular endurance? Give Joe’s HIIT workout a go. Trying to get a little swole? He’s got a strength training workout for that. From fitness tips to nutrition hacks, Joe will have you feeling healthier in no time.
Knee crunches are an effective upper-body exercise designed to build core strength and target your abdominal muscles. Learn more about the benefits of knee crunches and tips for performing this exercise properly.

Knee crunches are an effective upper-body exercise designed to build core strength and target your abdominal muscles. Learn more about the benefits of knee crunches and tips for performing this exercise properly.

Knee Crunch Guide: How to Do Knee Crunches Properly

The knee crunch is a bodyweight exercise that helps build core strength and targets your abdominal muscles. Knee crunches add a challenging twist to a range of motion similar to sit-ups and basic crunches. To do knee crunches, lie flat on your back with your hands behind your head, knees bent, and feet on the floor. Lift your knees so that they form a 90-degree angle, then bring your head toward your knees by crunching your stomach muscles. Return to the starting position before repeating. Once you&#39;ve mastered knee crunches, try knee crunch alternatives such as <a href='https://www.masterclass.com/articles/reverse-crunch-guide' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/reverse-crunch-guide","linkCopy":"reverse crunches","category":null}'>reverse crunches</a>, knee-ups, bicycle crunches, and <a href='https://www.masterclass.com/articles/mountain-climber-exercise' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com/articles/mountain-climber-exercise","linkCopy":"mountain climbers","category":null}'>mountain climbers</a>.

What Are Knee Crunches?

There are several notable benefits to regularly practicing knee crunches.<ol class="mc-m-4"><li class="mc-my-4"> 1. Knee crunches can help you achieve six-pack abs. The primary muscle targeted by knee crunches is your rectus abdominis, the core muscles responsible for the six-pack. </li><li class="mc-my-4"> 2. Knee crunches build lower-body strength. In addition to targeting your core, knee crunches build strength in your hip flexors, lower back, and lower abs. </li><li class="mc-my-4"> 3. Knee crunches are a convenient home workout. Knee crunches are a bodyweight exercise that do not require you to have any special exercise equipment, making them easy to practice at home. </li></ol>

3 Benefits of Knee Crunches

For knee crunches, begin by performing 2–3 sets of 10–15 repetitions. Choose your sets and repetitions based on your ability to maintain good technique throughout.<ol class="mc-m-4"><li class="mc-my-4"> 1. Lie face-up on an exercise mat with your knees bent and your feet on the floor. Place both of your hands on the back of your head without interlocking your fingers. Your ribs should be down and your pelvis should be slightly tucked. </li><li class="mc-my-4"> 2. Engage your core. Your chin should remain tucked throughout the movement, as if you were holding an egg under your chin. </li><li class="mc-my-4"> 3. Lift your knees toward your chest so your knees are directly over your hips. All repetitions should begin from this starting position. </li><li class="mc-my-4"> 4. Begin the upward movement by squeezing your abs. Curl your shoulders off the floor while squeezing your abs. Pause at the top of the movement. </li><li class="mc-my-4"> 5. Slowly lower to the starting position while maintaining tension on your abs. </li><li class="mc-my-4"> 6. Repeat for your desired number of repetitions. </li></ol>

How to Do Knee Crunches With Perfect Form

If you have a previous or pre-existing health condition, consult your physician before beginning an exercise program. Proper exercise technique is essential to ensure the safety and effectiveness of an exercise program, but you may need to modify each exercise to attain optimal results based on your individual needs. Always select a weight that allows you to have full control of your body throughout the movement. When performing any exercise, pay close attention to your body, and stop immediately if you note pain or discomfort.To see continual progress and build body strength, incorporate proper warm-ups, rest, and nutrition into your exercise program. Your results will ultimately be based on your ability to adequately recover from your workouts. Rest for 24 to 48 hours before training the same muscle groups to allow sufficient recovery.

How to Work Out Safely and Avoid Injury

Throw on some athleisure, fire up a <a href='https://www.masterclass.com' target='_self' class='mc-text--link' data-mc-segment-trigger='true' data-mc-segment-event-type='Article Page Click' data-event-obj='{"textTag":"p","href":"https://www.masterclass.com","linkCopy":"MasterClass Annual Membership","category":null}'>MasterClass Annual Membership</a>, and get ready to sweat it out with exclusive instructional videos from Nike Master Trainer and GQ fitness specialist Joe Holder. Want to improve your cardiovascular endurance? Give Joe’s HIIT workout a go. Trying to get a little swole? He’s got a strength training workout for that. From fitness tips to nutrition hacks, Joe will have you feeling healthier in no time.

Want to Dive Deeper Into Your Wellness Journey?

Knee crunches are an effective upper-body exercise designed to build core strength and target your abdominal muscles. Learn more about the benefits of knee crunches and tips for performing this exercise properly.

Knee crunches are an effective upper-body exercise designed to build core strength and target your abdominal muscles. Learn more about the benefits of knee crunches and tips for performing this exercise properly.
