10 Best Core Exercises for CrossFit to Help You Crush Your Next WOD

Yes, CrossFitters need core exercises, too. Try these core moves to improve your form and bust through CrossFit plateaus.

Ask anybody in your gym, and they’ll all probably have slightly different definitions of what it means to have a strong core. Some will say a visible six-pack, while others will talk about how long they can hold a plank. CrossFit’s definition of core strength is midline stabilization — the ability to keep your trunk in a static, controlled position. 

athlete outdoors performing crossfit ab exercises on the ground with medicine ball
Credit: Shopping King Louie / Shutterstock

Both in and out of your CrossFit box, a strong core is essential for improving efficiency, power, and overall performance. Without it, your progress is sure to stall. Below are 10 core exercises that are essential for CrossFitters. Some are foundational to learning and reinforcing higher-level skills, while others are popularly seen in CrossFit conditioning workouts. 

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10 Best Core Exercises for CrossFit 

Here are the 10 exercises broken down into three distinct categories. 

Foundational Positions 

Assistance Exercises 

Why Should CrossFitters Train Their Core?

Direct trunk work develops body awareness, allowing you to understand the difference between a neutral position versus a loss of midline stability. It also allows you to feel the differences between hip flexion, trunk flexion, hip extension, and trunk extension. 

All this body knowledge is essential for gauging when your kipping pull-ups are helping you get stronger versus when they might be setting you up for injury due to improper form. You’ll also be able to get a feel for when your overhead squat form is locked in, all to help you move more efficiently.

Most of the movements in CrossFit require balance, coordination, speed, and timing. It’s important to have the strength and awareness to maintain a stable midline while the mind is focused on the technique of these high-skill movements.

Foundational Positions

Core strength is key to progressing in so many CrossFit workouts. Without the ability to hold certain positions, there are CrossFit moves that are doomed to fail before you even start. Here are the core exercises every CrossFitter might want to practice before their next WOD.

Hollow Rock

The hollow rock is a cornerstone gymnastics exercise. It targets trunk flexion and lower abdominal recruitment. When performed correctly, this movement serves as an excellent ab strength and conditioning tool.

This exercise also develops important body awareness that will help you keep on task with your pull-ups and other complex movements on bars or rings.

Benefits of the Hollow Rock

  • Global Flexion: The hollow position is unique in that it isometrically challenges your body from head-to-toe.
  • Lower Abdominal Recruitment: Maintaining flexion in your lower back requires constant recruitment of your lower abs to prevent the spine from arching and losing the hollow shape.
  • Body Awareness: This movement requires full body contraction to statically hold the correct position, developing incredible awareness that translates to higher-skill kipping movements on the pull-up bar.

How to Do the Hollow Rock

Lie on your back with your legs together and your arms stretched overhead. Squeeze your feet together, contracting your quads and glutes simultaneously. Crunch your chest up towards the ceiling. Your hands and feet should be six to 12 inches off the ground, with your entire body forming a banana shape, mimicking the bottom of a rocking chair. 

Once this position is accomplished, pull your heels down towards the floor while maintaining the rigid hollow shape. This will initiate the momentum of rocking. You should continue to rock while focusing on not allowing your lower back to arch or lose its solid position. 

Arch Hold

The arch is the backside counterpart to the hollow position. Mastering the arch will allow you to have balanced strength and power during kipping movements

While holding this position isometrically isn’t something you’re going to have to do explicitly during a WOD (workout of the day), strengthening the position will work wonders for your CrossFitting abilities. Building the strength and stability required for holding this position will carry over into tremendous work capacity for your glutes, hamstrings, and back.

Benefits of the Arch Hold 

  • Global Extension: The arch also challenges your body from head to toe, but this time isometrically challenges the posterior muscles. 
  • Posterior Chain Stamina: The glutes, hamstrings, and erectors are under constant tension during the arch hold, which develops incredible muscular endurance
  • Shoulder Mobility: The correct arm position in the arch is that your elbows and arms are even with your ears. You will quickly realize that your shoulders and upper back muscles are working hard to maintain this active position.

How to Do the Arch Hold 

Lie on your stomach with your legs together and arms stretched overhead. Simultaneously lift your chest off the ground as you lift your feet and knees from the ground. Actively squeeze your glutes hard while keeping your legs straight to prevent hyperextension of your lower back.

Lift your hands and elbows so that your arms are even with your ears. Your head should remain in a neutral position with your torso. This shape should look similar to that of the hollow, but now your body is oriented in the prone position. 

You’ll see the following CrossFit core exercises pop up in plenty of workouts at your local box. If you’re not familiar with them, try practicing them on their own, outside the context of a WOD. That way, when you do encounter them as part of a structured workout, you can handle them effectively.

AbMat Sit-Up

The AbMat sit-up is an effective way to target dynamic trunk flexion work, forcing your abdominals to work by eliminating the ability of your hip flexors to contribute to the movement.

All too often, your hip flexors will inadvertently take over during ab workouts such that they’re getting more work than your actual abdominals. But using an AbMat — or alternatively, a stability ball — you’ll be able to take your hip flexors out of the equation to keep all the emphasis on your abs.

Benefits of the AbMat Sit-Up

  • Isolated Ab Exercise: Keeping the soles of your feet pressed together inhibits contribution from your hip flexors. This forces your abs to work dynamically. 
  • Safe Range of Motion: The AbMat preserves the natural curve that many people have in their lower back. This allows the spine to dynamically flex and return to neutral without an excessive range of motion.
  • Compliments the Glute-Ham Developer (GHD) Sit-up: The AbMat sit-up is performed with a static hip and dynamic trunk, which is the opposite of how the GHD sit-up is performed. These two movements complement and can supplement each other. 

How to Do the AbMat Sit-Up 

Sit in a butterfly stretch with the soles of your feet pressed together and the AbMat placed right up against your glutes. The higher side of the AbMat should be against your tailbone, not the other way around. Lie back all the way so that your shoulders and upper back rest on the ground with the AbMat filling the space between your lower back and the ground. 

The outsides of your feet should remain in contact with the ground during the full range of motion. Contract your abs and sit up so that your shoulders pass your hips, then return back down to the lying position. 


The V-up is an excellent core exercise that incorporates a static hollow body and dynamic hip flexion exercise. It serves as a progression toward an the toes-to-bar while developing hip flexor strength and hamstring flexibility

If you’re not yet able to perform a full set of toes-to-bar reps, start with V-ups and build your way up from there. They are an eligible substitute if you need to scale down toes-to-bar but still want to smoke your core and hip flexors.

Benefits of the V-Up

  • Hip Flexor Strength: Raising your feet up targets your hip flexors directly, but the V-Up is unique in that your shoulders are crunched off the ground simultaneously. This removes a compensation point for your upper body to create leverage and swing your feet. This does a fantastic job of isolating and exposing hip flexor weakness
  • Hamstring Flexibility: In order to crunch up and touch your toes while your legs remain straight, there needs to be a significant degree of hamstring flexibility. It’s appropriate to slightly bend your knees and straighten over time as flexibility increases
  • Toes-to-Bar Progression: The V-Up isolates the core strength and stamina needed for the toes-to-bar without the demand on your grip and upper body strength. This is a fantastic tool to train in parallel to toes-to-bar kipping progressions so that your midline is ready once your upper body has progressed. 

How to Do the V-Up 

Lie on your back and follow the same process of getting into a hollow shape as you did for the hollow rock. From the hollow position, raise your feet up so that they are directly over your hips. Simultaneously crunch up to touch your toes with your hands. Lower back down to the hollow position with control. Repeat for reps. 


The toes-to-bar exercise builds grip and upper body strength while developing ab and hip flexor stamina through dynamic hip flexion. You’ll be targeting your core for both explosive strength and stamina — a powerful combination that you definitely need to be a successful CrossFitter.

This move requires you to combine a tremendous amount of upper body strength and stability with your core strength and midline stability. It might take a lot of practice and build-up to accomplish even one rep, but keep at it and you’ll get there.

Benefits of the Toes-to-Bar

  • Grip Strength: The toes-to-bar requires you to complete your reps while hanging from a pull-up bar. This puts your grip under constant tension and will develop massive grip strength while simultaneously targeting your midline.
  • Upper Body Strength: As your body transitions from arch to hollow, your hands and arms press the pull-up bar down towards your feet, activating your upper back, shoulders, and pecs to complete each rep. This builds a unique strength in that it is one of the few straight-arm pressing movements used in CrossFit. 
  • Dynamic Hollow and Arch: Kipping work on a pull-up bar puts a huge spotlight on the integrity of your hollow and arch positions. It’ll remind you to keep your basics crisp.

How to Do the Toes-to-Bar 

Hang from a pull-up bar with your hands in shoulder-width apart. Press the bar down and simultaneously crunch into the hollow position. Quickly allow yourself to swing down and forward, pulling your feet back and squeezing your posterior into the arch position. 

Once you feel the apex of the arch, initiate the next kip by pressing down and returning to the hollow. In one or two swings, you should be able to build enough momentum so that as you swing back behind the bar in your hollow, you should press down, lie back and bring your toes to touch the bar. Once your toes make contact, actively bring your feet down and pull back into the arch again. Repeat this process for reps. 

Glute-Ham Developer Sit-Up

The GHD sit-up is one of the most difficult and potent core exercises. It requires incredible flexibility and ab strength while building muscle endurance in the hip flexors.

There’s a reason you see this move tested so regularly at elite events like the CrossFit Games. It takes elite-level strength, coordination, and even confidence to be able to bang out a solid set of these — and then come back for me.

Benefits of the Glute-Ham Developer Sit-Up

  • Trunk Stabilization: The large degree of extension in your trunk during the negative portion of this movement requires incredible stability to resist the hyperextension of your spine. 
  • Rectus Femoris Development: When properly executed, the GHD sit-up rapidly contracts your rectus femoris, which is a quad muscle that attaches to the pelvis. This is a powerful muscle responsible for hip flexion. 
  • Global Extension Flexibility: The GHD sit-up demands a large degree of global extension compared to the arch. This will require a great degree of flexibility and should be progressed from a parallel GHD sit-up until you can accomplish a full range rep with no tension or pain in your hips or back.

How to Do the Glute-Ham Developer Sit-Up 

Sit on the large pads of the GHD and set your feet securely between the foot holds. When sitting atop the pads, there should be a slight bend in your knees, as you’ll want to scoot back once your feet are secured. Start with your fingers touching the foot holds and then lie back while simultaneously pulling your toes towards yourself to keep your feet secured. 

Lie back as far as you can while maintaining a stable extended trunk position. Ideally, you’ll be able to reach overhead and touch the ground behind you, but this should be worked up to. From the bottom position, rapidly extend your knees and contract your quads. This will shoot your torso up, back toward the starting position. 

It’s important to note that you will be starting with your knees slightly bent, and they should remain slightly bent throughout the entire descent of the movement. Only once you’re trying to change direction should you rapidly extend your knees. As soon as you extend your legs, allow your knees to soften and rebend. This is the most important aspect of properly performing this movement. 

This knee extension forces your rectus femoris to be the primary mover. If you maintain a knee bend and pull yourself up to the starting position with the trunk, you will be using the iliopsoas muscle. The problem with this is that the iliopsoas attaches to both your pelvis and lumbar spine. This will put unnecessary strain on the spine, while the rectus femoris is only attached to the pelvis, making it much safer.

Assistance Exercises

You won’t necessarily see these moves in a WOD, but they’ll come in handy in preparing you for them. These CrossFit core assistance exercises will ready your body to take on pretty much any challenge. 

Lying Leg Lift

Lying leg lifts are a great assistance exercise to build up your hip flexors for movements like V-ups, toes-to-bar, and L-sits. You can use this move as a substitute for more advanced exercises if necessary.

You can also opt to practice this movement relatively often until you develop the skills and strength you need to complete more complex variations. Focus on training these to failure, teaching yourself to go hard in a relatively safe position.

Benefits of the Lying Leg Lift

  • Great for Stamina and Conditioning: Lying leg lifts can safely be trained to failure, making it a great exercise to condition and build muscle stamina in your hip flexors and abs.
  • Beginner Friendly: This movement is very low-skill and not as challenging as other foundational movements like hollow rocks and L-sits. 
  • Helps CrossFit Movements: Lying leg lifts are an excellent assistance exercise to help break plateaus in higher skill movements, such as toes-to-bar and V-ups. 

How to Do the Lying Leg Lift

Lie down on your back with your legs straight, keeping your hands by your sides. Raise your legs up so your feet are directly over your hips, forming an “L” shape with your torso. Lower your legs back down to about six inches from the floor. Raise them back to the top position. Place your hands under your glutes if your lower back is arching or feeling discomfort. 

Seated Leg Lift

The seated leg lift is another assistance exercise to improve L-sits. It also serves as a great hip flexor warm-up for movements demanding activation of this muscle group.

You’ll often be building up to L-sits with this exercise, but that doesn’t mean it’s not a beast of a move on its own. Take advantage of its low-impact nature to weave it into your warm-ups while also gaining a whole lot of strength.

Benefits of the Seated Leg Lift

  • Improves L-Sits: The seated leg lift directly mimics the position of the L-sit, while allowing the movement to be repetition-based instead of isometrically held for time. This allows an alternative way to strengthen your hip flexors in this position. 
  • Activates the Hip Flexors: This movement is a quick and easy way to warm up and activate your hip flexors for higher-impact movements like running, GHD sit-ups, and L-sits.
  • Low Impact: This is a great alternative to the L-sit because it puts less strain on your trunk (specifically your lower back). It allows you to isolate your hip flexors without the added demand of midline stabilization that a static L-sit requires. 

How to Do the Seated Leg Lift

Sit on the floor with your legs out straight in front of you. Sit up straight and squeeze your legs together while pointing your toes away from you. Place your hands on the ground so that you can perform this movement correctly. Placing your hands closer to your feet will increase the difficulty while moving your hands behind your body will make it less challenging. 

Raise your heels six to 12 inches off the floor and lower them back down so that they are only a couple of inches from the ground. Repeat this process of lifting up and down without letting your heels touch the ground. 

Glute-Ham Developer Hip Extension

The GHD hip extension is an extremely important assistance exercise to build muscle, strength, and stamina in your posterior chain. It simultaneously demands trunk stabilization as the posterior muscles raise the midline from the upside-down “L” shape and keep your trunk parallel with the floor. 

This is also a complex, advanced movement that may require quite a bit of practice to work up to. That said, the payoffs to your back strength and weightlifting movements will come in spades.

Benefits of the Glute-Ham Developer Hip Extension

  • Strong Back: The hip extension forces your erectors, glutes, and hamstrings to raise your trunk to the top position of the movement. This strengthens your posterior chain muscles, giving you a stronger back
  • Support Your Knees: The muscles behind your knees where your calves and hamstrings meet are not talked about but are extremely important to maintaining knee health. The hip extension is a great exercise to begin the process of strengthening these muscles, and can later be progressed to the glute-ham raise to place further demand on this specific area.
  • Improves Weightlifting: Building a strong and muscular posterior chain will translate to more complex barbell movements, such as squats, deadlifts, presses, snatches, and clean & jerks.

How to Do the Glute-Ham Developer Hip Extension 

Set yourself in a prone position on the GHD. The pads should be set on your upper thighs, with your hips and pubic bone being free and untouched. Your feet should be set in the foot holds, pointing down. 

Start in a sorensen hold, which is when you isometrically hold your entire body parallel to the floor with your hands set on your chest or behind your head. From here, lower your torso down while maintaining a static, neutral spine. When your belly comes in contact with the pads, your torso should form an upside-down “L” shape with your legs

During the descent, allow your knees to unlock so your hamstrings can properly stretch. Raise your torso back to the starting position by squeezing your glutes and posterior muscles, straightening your knees at the top parallel position. 


The L-sit is the king of core exercises. This simple and devastating movement removes the ability to cheat or rush. The stopwatch does not lie, and the position is so simple that any deviation from the correct shape will be obvious. 

Don’t worry if you can’t quite master the L-sit right away. You’ll likely need to build up to this complex movement by strengthening your core with a variety of other exercises first.

Benefits of the L-Sit 

  • Hip Flexor Strength and Stamina: The hip flexors don’t get enough credit in their contribution to astonishing core strength. The torque created at your hips from holding your legs out straight during the L-sit develops world-class strength and stamina to prevent your feet from falling or allowing your lower back to arch. 
  • Faster Running: Strengthening your hip flexors can help make you a faster, more efficient runner. This will definitely come in handy in a lot of WODs — Murph, for example. 
  • Shoulder Stability: Holding your entire body weight in the support position requires great upper-body strength and shoulder stability. This will aid with other CrossFit movements such as ring dips and ring muscle-ups

How to Do the L-Sit 

Set a pair of parallettes roughly shoulder-width apart. Set your hands on the handles with your hips in line with your hands. Keep your legs together in front of you with your feet on the ground. When ready, lift both feet so that your torso and legs form an “L” shape.

Your arms and legs should remain perfectly straight and your hips should stay in line with your arms. You can modify the difficulty of this by bending your knees into the tuck position or practicing with only one leg raised at a time. 

Programming CrossFit Core Exercises

A great rule of thumb for CrossFit programming is to always let form dictate the number of reps or your amount of time under tension. When mechanics start to break down, it’s smarter to take a break and recover so that you can always practice with the correct technique. This serves to minimize injury risk while also ensuring that you’re engraining proper muscle memory

When performing a set of a given movement during training, aim to leave two to three reps in reserve (RIR). This means you feel like you had a few reps in the tank before you’d fail. This method can be used on a day-to-day basis depending on how you’re feeling on a given day. Aim to perform three to five sets of exercises and incrementally progress volume over time.

CrossFit Core Training Tips 

You can implement core training into your daily warm-ups and accessory work. This is a great way to balance movement patterns and keep your body strong and healthy. 

Incorporate Core Training into Warm-Ups 

Midline exercises won’t always be included in the daily workout, so a great strategy is to incorporate core training into warm-ups. This allows you to keep the pattern of daily training while activating muscles specific for the workout ahead.

For example, if the WOD includes running and deadlifts, mixing GHD hip extensions and lying leg lifts into the warm-up will be a great way to activate the muscles needed for those movements. 

people in the gym doing a dynamic warm up or stretching
Credit: Ground Picture / Shutterstock

Another added benefit of incorporating core training into warm-ups is skill development. Mixing in hollow rocks and arch holds prior to kipping work reinforces the correct positions needed for higher-skill movements like pull-ups, toes-to-bar, bar muscle-ups, and ring muscle-ups.

Superset Core Training With Accessory Work

Supersetting core movements into an accessory session is an efficient way to add extra midline work into training. The muscles you’re targeting will have time to recover while the core movement is being performed, and there will be added cardio benefits from supersetting.

Balance Movement Patterns 

Post-workout core training balances the movement patterns targeted in the strength and/or conditioning segments completed that day. For example, if the workout consisted of biking and kettlebell swings, the main movement pattern for that day would be hip hinging and hip extension. A good way to balance this out would be to do a few sets of hip flexion exercises, such as GHD sit-ups, to balance out the movement at your hips. 

Don’t Make it Complicated 

Keep it simple and do the basics extremely well. You’re most likely going to hit the popular conditioning movements frequently, so mix in hollow and arch work and assistance exercises to refine your fundamentals and strengthen lagging muscle groups.

Give yourself a challenge and try to hit some core work every day for two to four weeks. See how you feel and continue to mix it in from there.

Featured Image: Jacob Lund / Shutterstock