A stronger, more muscular core has long been one of the most coveted goals when it comes to working out. However, all too often, the obliques get ignored. It’s crucial to strengthen these muscles, which run along the sides of your abdomen, for the sake of improving athletic performance and supporting many movements throughout daily life.

Side crunches (aka oblique crunches) are among the best exercises for the obliques since they’re simple, accessible, and effective in equal measure. Keep reading for our comprehensive guide to side crunches—including their key benefits and how to do them safely, according to Peloton instructor Emma Lovewell and physical therapist W. Zach Smith, founder and owner of HIDEF Physical Therapy.

What to Know About the Oblique Muscles

The internal and external obliques are part of the main muscle group that makes up the abdominals, alongside the rectus abdominis (the topmost layer of muscle that runs along the front of your stomach) and the transversus abdominis (the deepest ab muscle that wraps around your abdomen like a corset).

Located on each side of the rectus abdominis, the obliques wrap from the front of the body around your sides and attach to your spine. “Their job is to rotate and laterally flex the spine,” Smith says. “They also play a key role in stabilizing your spine and resisting rotation and lateral flexion.”

You activate the obliques often, likely without even noticing it, such as when you turn around, pull a door open, or bend down to tie your shoes. Plenty of common core exercises—including but not limited to moves like side planks, dead bugs, and bird dogs—will also work the obliques. Yet, according to Smith, the greatest oblique-strengthening benefits come when you do anti-rotation exercises and side-bending exercises like the side crunch.

4 Benefits of Doing Side Crunches

All too often, core workouts focus on defining the rectus abdominis to create that coveted six-pack. Other times, people prioritize larger muscle groups—such as the arms, shoulders, or glutes—for muscle gains. However, side crunches—and other targeted oblique work—is important to include in your workout routine for several reasons.

1. They Help Target and Activate Your Obliques

Side crunches are particularly great at isolating the obliques. While they may engage fewer muscles than, say, a plank, this allows you to focus on the targetted muscle group. “We like to include dedicated exercises for the obliques because it helps to get maximal contraction, which leads to better strength and aesthetics of the muscle,” Smith says.

2. They Improve Spinal Stability

By activating and building strength in your obliques, side crunches assist in stabilizing your spine. In turn, this helps protect spine and nerve health, maintain balance and posture, and allows for proper force transfer between your upper and lower body (think: the way you use momentum during snatches or thrusters).

3. They Can Enhance Athletic Performance

Improving core strength and spinal stability with side crunches and other oblique moves can also boost athletic performance. According to Smith, oblique crunches can improve your ability to quickly change directions while playing soccer and basketball, as well as amplify your skills in tennis, baseball, golf, and other sports that require rotating your body.

4. They’re Safe and Accessible for Most People

Last but not least, Emma says that side crunches are fairly accessible for most people. “You may need to make some modifications and ease into this movement if you have a history of back pain, but for the majority of people this is a safe and effective exercise for the core,” Smith adds.

How to Do a Side Crunch (aka Oblique Crunch)

There are a lot of different ways to do side crunches. Here, Emma shares simple instructions for doing side-lying side crunches. 

3 Form Tips for Oblique Crunches

Oblique crunches are simple enough; just be sure to heed the following tips to avoid making a few common mistakes, which can compromise the integrity of the exercise and lead to aches, subpar results, or even injury.

1. Avoid Pulling on Your Neck

According to Emma, yanking your head up is a common mistake associated with side crunches. To fix this, keep your elbow wide and your neck long. Think about lifting with your chest, not your head or chin, Emma says.

2. Fully Engage Your Core

Crunching without actually engaging your core is another common mistake Emma witnesses during side crunches. The fix? “Brace your abs as if you’re preparing for a punch before each rep,” she says. Similarly, avoid putting too much weight into your bottom hand; doing so will take the work out of your obliques.

Moving slowly is also crucial to maintain the form and integrity of this exercise. Isolation exercises that target the abs are notoriously tough, and many people tend to race through them. However, rushing through reps isn’t the right way to go. “Slow down, engage the core, and move deliberately,” Emma says.

3. Move from the Torso, Not the Hips

“One common mistake people make with these movements is compensating with the hip flexors,” says Smith. He instructs people to lock the hip in place and think about curling up from the torso instead.

“Try and get your ribs to touch your hip bone on the side, which will indicate that you are really using your obliques,” he adds.

Side Crunch Variations to Try

Here, Emma offers two variations of the side crunch. The first is the standing side crunch, which might be easier and more comfortable for some, including those who experience hip pain. The second is the oblique V-up, which provides an extra challenge for balance and stability (and of course, a slow burn for your obliques).

Standing Side Crunch

According to Emma, this standing core exercise is a great low-impact option for combining core strength and cardio.

Oblique V-Up

It’s a good idea to try this variation only once you’ve nailed the side-lying oblique crunch. “This advanced side crunch variation requires strong core engagement and balance,” Emma notes.

How to Add Side Crunches to Your Routine

Side crunches are a worthwhile exercise for anyone who wants to improve spinal stability, boost athletic performance, or simply move throughout their days with more ease and agility.

To add side crunches to your routine, consider: