How Many Crunches Should I Do Based On My Fitness Goals?

Almost everyone would love to have defined six-pack abs or a toned, flat stomach. For this reason, almost every client that I work with as a Certified Personal Trainer is interested in the best ab exercises to get a sculpted midsection.

Because crunches are a well-known ab exercise that even novices may remember from physical education class or youth sports like push-ups and squats. Many beginner ab workouts include crunches.

This then often leads to one of the most common questions that I get asked: How many crunches should I do to get abs?

However, I usually tell all of my clients that doing crunches is not the most effective way to strengthen your ab muscles or improve functional core strength.¹

Instead, I generally program core workouts with ab exercise alternatives to crunches. But, crunches can potentially have their place in a body strength training core workout routine.

This guide will discuss how to perform crunches, give you alternative ab exercises to add variety to your ab workout routine, and ultimately answer your question, “How many crunches should I do in my fitness routine workouts?”

Lets jump in!

How Do You Do Crunches?

Before we look at how many crunches you should do in ab workouts, lets cover how to perform crunches.

The key to ensuring that crunches are both safe and effective in terms of actually engaging the muscles targeted by crunches is contingent upon using proper form.

Here is how to do a basic bodyweight abdominal crunch:

How To Perform Crunches

Lie on your back with your knees bent and your feet on the floor. Make sure that your feet are hip-width apart and your toes are pointed straight ahead.
Try to press your lower back into the ground.
Cross your arms over your chest or place your hands behind your ears, gently cradling your head.
Inhale, contracting your abs to lift your head and shoulder blades off the floor while keeping your lower back and hips down on the floor. Instead of thinking about curling up so that your face is looking at your feet, think about lifting your upper body with your abs as you keep your gaze pointed at the ceiling. (Think up, not forward.).
Pause and hold this lifted position, squeezing your abs and thinking about sucking in your stomach to press your belly button and lower back into the floor.
Slowly lower your head and shoulders back to the starting position.

One important point is that from a movement pattern perspective, the primary difference between sit-ups vs crunches is that with sit-ups, you are moving through a larger range of motion to lift your entire torso off of the ground into a fully upright position.

With a crunch, you just lift your head and shoulder blades off the floor.

There are also variations to basic crunches, such as bicycle crunches, where you would bring your left elbow to your right knee and alternate sides; reverse crunches, side plank crunches, and stability ball crunches, among others.

Are Crunches Good for Abs?

Regular crunches involve only strengthening the abs in the flexion direction because the range of motion is limited by the flat surface of the floor.

Studies suggest that doing crunches is not the most effective way to strengthen your abdominal muscles or improve functional core strength.²

You also need to do core exercises for extension, lateral flexion, and rotation.

Additionally, performing crunches is contraindicated for certain populations because of the flexion it imposes on the spine.

With any of the following conditions, you should speak with your doctor or physical therapist before doing crunches or ab exercises that cause spinal flexion:

Osteoporosis (doing crunches can increase your risk of further damage to your spine, such as causing vertebral compression fractures or exacerbating narrowing between your vertebrae)
Degenerative joint disease in your spine
Spinal stenosis
Herniated discs
Women who are pregnant
Men or women who are dealing with diastasis recti because of the increased intra-abdominal pressure and positioning inflicted by crunches.³

What Are the Best Ab Exercises Instead of Crunches?

The ab exercises you choose for your core workouts should be balanced in the sense that you work all of the different muscles in the core relatively equally.

The best exercises will be functional core exercises that train all of the major abdominal and core muscles simultaneously so that you arent developing muscle imbalances in the abs and lower back muscles.

Here are some alternatives to crunches that you can add to your core workouts:

#1: Planks

Regular flexion/extension core strengthening exercises that involve doing reps and moving your torso (like crunches and V-ups) are certainly important.

However, in order to build functional core strength effectively, you need to train the core muscles to not only permit but also restrict and stabilize against movements.

Abdominal planks are one of the best ways to build the muscular endurance and core stability you need to prevent flexion, extension, lateral flexion (side bending), and twisting of your trunk when you want your core and trunk to provide a stable, solid, base of support for your arms and legs.

According to research, planks have been found to increase core stiffness more than dynamic core exercises (like crunches or sit-ups).⁴

The benefit of increasing core stiffness is that having a stiffer core improves your ability to support the spine and improves the ability of the core to brace the spine for load-bearing activities properly.

For example, studies have found that isometric exercises for the core muscles can help reduce the severity of lower back pain.⁵

#2: Anti-Rotation Core Exercises

Anti-rotation core exercises train your core to provide stability while your arms or legs move.

Examples include Pallof presses, bird dogs, dying bugs, medicine ball chops, kettlebell swings, and windshield wipers.

Other good ab exercises to include in core workouts include Russian twists, V-ups, hanging leg raises, reverse crunches, single-arm farmers walks, and flutter kicks.

#3: Low Back Exercises

Of course, while having strong abs does look fantastic and provides functional benefits, the abdominal muscles are only part of the core.

In order to reduce the risk of injuries and have a functionally strong core, you also need to strengthen your lower back muscles.

Indeed, doing too many ab exercises and neglecting exercises that target the erector spinae and the multifidus muscle groups in the lower back can cause muscle imbalances between the flexors of the spine and the extensors.

This is why the best core workouts include core exercises specifically targeting the lower back extensors, such as the erector spinae muscle group and deep multifidus.

Examples of good core exercises for the low back muscles include the Superman exercise, the bird dog exercise, back extensions, and kettlebell swings.

How Many Crunches Should I Do Based On My Fitness Goals?

If you decide you still want to do crunches, the number of crunches you should do will depend on your fitness level, training goals, and the other workouts and exercises you are performing for the muscles worked by crunches.

Here are a couple of guidelines for how many crunches you should do:

How Many Crunches Should I Do As A Beginner?

A good starting place for beginners is two sets of 10 to 12 repetitions of crunches. Build up to three sets of 10 to 20 reps.

Remember to move slowly and hold the contraction at the top (without craning your neck).

How Many Crunches Should I Do to Strengthen My Abs?

Its better to add more resistance with crunches and perform fewer reps per set if your goal is to increase ab strength and build muscle.

You can add resistance by doing cable machine crunches, holding a weight plate, using resistance bands, or doing crunches on a slant board.

Progress to more advanced weighted core exercises as well, such as hanging leg raises with ankle weights or doing reverse crunches with a cable machine.

Just ensure you can safely handle the weight for crunches or ab exercises so you’re not straining your abs, hip flexors, or spine.

Perform 3-5 sets of 6-12 reps to build strength and muscle.

How Many Crunches Should I Do to Build Muscle Endurance?

The recommendation for the number of crunches you should do for muscle endurance is to perform 3-5 sets of 15 or more reps.

However, again, its better to incorporate other core exercises rather than doing tons of crunches so that you have a well-rounded core strengthening routine.

Consider trying an ab circuit workout for muscle endurance.

For a complete cable ab workout to work your upper abs, lower abs, and obliques, click here!

How Many Crunches Should I Do Based On My Fitness Goals?

Plus, our personal trainer gives us her expert advice on the best exercises to strengthen your core.