Get Fitter, Faster: Fitness, Food & Health Hacks

Hey, I'm Julien. I share a weekly newsletter designed to make you fitter. It's short, smart and actionable17k read it, I'd love you to join too. It's free.

I want to get fitter

The Ultimate Guide to Oblique Crunches: Variations & Benefits

 Written by 

Julien Raby

 Last updated on 

Oblique crunches are an amazing ab exercise to round out your ab training. In relation to a lot of the common exercises, people do like leg lifts. But a lot of people neglect oblique exercises.

In this article, we are going to tell you everything you need to know about oblique crunches. What are oblique crunches? Also, we want to look at the actual anatomy and physiology of how the obliques work. And then we are going to show you a couple of oblique crunches variations that you can do to properly train your obliques so that you’re not doing those crunches where people are just going from side to side. Let’s get started.

A man performing oblique crunches at home
  • Save

What Are Oblique Crunches?

The oblique crunch is a bodyweight exercise. This movement works both the external and internal obliques through rotation by crunching or lifting your upper body towards your lower body.

What Muscles Do the Oblique Crunches Work?

The oblique crunch targets the internal and external oblique muscles. Also, it strengthens the abdominal and back muscles.

In order to help you understand this stuff, we have to look at the basic anatomy of the muscles, the direction of the muscle fibers, and the insertion points, so you can understand what the function of each of these muscles is.

The Anatomy of The Oblique Muscle

Where are your internal and external obliques? It’s important to understand that they’re layered over top of one another. But underneath them is a muscle called your transverse abdominis. 

The muscle fibers that are the transverse abdominis run horizontally but it actually acts like a girdle or a corset. As those muscle fibers shorten, they squeeze in and that’s what’s going to pull your abdomen in. 

So, that’s layer number one. Outside of that is the next layer and that’s going to be your internal obliques. They’re called internal because the external obliques lie on top of them.

The Direction of the Oblique Muscle Fibers

You actually can’t really see your interior obliques. The muscle fibers of internal and external obliques actually work together. They run in opposite directions. 

If you are going to bring your left shoulder towards your right knee and you crunch this way, your internal obliques on this side are shortening, helping pull you in this direction. And then the external obliques on the opposite side help pull and twist forward. So, both your internal and external obliques are working in unison.

image 66
  • Save
Internal Obliques muscles.
Credit: Kenhub

The Function of The External Obliques

The external obliques are one of the largest muscles in our torso. It’s the ultimate job of the external obliques to balance out through rotation.

The other thing the external obliques do is they pull the chest down. If you didn’t have external obliques, your chest would constantly be floating up and wouldn’t have the actual strength to be held down. 

So, when you flex your abs and pull your chest forward, your external obliques are actually engaging. They play a very big role there. 

The Function of The Internal Obliques 

The interior obliques help force respiration and the diaphragm out. So, the interior obliques, when they are in shape, can actually help you breathe a little bit better. 

They are playing a role in how our diaphragm works, how our chest works but also how our abdominal cavity is held together and structured and stabilized. So, before you start thinking that it’s all about just avoiding the oblique training to avoid getting a wide waist, make sure you take a good look at how your core structure truly is.

How to Do Oblique Crunches

Here is a proper form of oblique standard crunches:

Use an exercise mat for this. Lie on your back with your knees bent and your feet on the floor. Place your fingertips on the back sides of your head. Drop both of your knees to your left side. Contract your abdominals as you lift your shoulder blades off the mat. Make sure to keep your elbows wide. Lower your upper body back to the starting position. Perform to a goal of 20 repetitions and repeat on the other side.

A man doing oblique crunches at the gym
  • Save

Benefits of Oblique Crunches

Here is why we advise this exercise rather than another:

1. It Makes Your Waist Tied In

Some people talk about not training the obliques because they don’t want to have a wide waist. However, you can have big obliques if you are genetically predisposed to having large obliques just because it’s your structure or you’re possibly taking something that’s allowing muscles to grow too fast. 

Generally, the obliques are small muscles. They don’t bulk out. Oblique crunches won’t make your waist look giant even if you have decent-sized obliques. They will make your waist look a little bit different and a little bit tied in.

By the way, if you look at old-school bodybuilders like Frank Zane and you see them on stage and they do these cool vacuum poses, that’s your transverse abdominis pulling your waist in making it nice and tight and small like that. 

2. Better Posture

Some people don’t like crunches because they put too much excessive strain on the spine. And it’s not a natural movement. But oblique crunches significantly strengthen our obliques and improve our posture.

3. It Increases Your Core Strength

By performing oblique crunches properly, you’re going to build core strength. You also enhance the way that your abdominal muscles look, not detract from it. Because the obliques when they’re in shape actually tie your abs in together quite well and create the illusion that we’re all looking for. They give you the illusion of a smaller waist even if it’s not super small.

4. Improves Balance

Oblique crunches exercise is helpful if you want to improve your balance. You can perform the standing oblique crunches to reach this fitness goal.

5. Relief Back Pain

If you are neglecting your external obliques, you’re putting yourself at risk for a serious back injury. Because we do need those to support that kind of rotation.

The standing oblique crunches are a great core exercise especially for those with any lower back or neck issues because you stay standing; and it’s an awesome cardio core exercise as well.

A woman doing oblique crunches outside
  • Save

Variations of Oblique Crunches

We provide you with our tips so that you can make sure you’re doing the crunch properly. 

1. Dumbbell Oblique Crunches 

Bring your left hand to your external oblique. Hold a dumbbell in your right hand. You’re going to stretch to the right and then come up and contract to the left. You’re going to inhale, stretching down to the right. Exhale, contracting your external oblique to the left. Switch sides. Same thing, stretching to the left now.

2. Oblique Crunch on a Hyperextension Machine

You’re going to make sure that when you put your feet on your platform, both your legs probably aren’t going to fit side-by-side.

You want to have your left foot forward and right foot back if you’re working on the left side. That’s usually what makes this the most comfortable stance possible. You can put both your hands behind your head. You can cross them. 

Some people will hold a weight like a dumbbell in the hand that is closest to the ground to be able to add on additional resistance. But we recommend starting with body weight. Because if you’re doing these right, you probably won’t need much resistance.

It’s all about making sure you have that mind-muscle connection of only using your oblique to get you up versus momentum.

Put your hands behind your head. You’re going to dip down as far as you can, getting a good stretch but without bending your knees. Because there’s no reason for that. You’re just going to bend as far as you can go in that range of motion. 

Keep your shoulders square forward. You want to make sure that you’re not bending forward or turning backward. It’s putting a lot of pressure on the back. 

When you come back up, don’t just elevate. Squeeze like you want to pinch this as hard as you possibly can. Blow out all the air that you can and squeeze this muscle to its fullest. Then you’ll switch to the other side and do the same thing.

3. Standing Oblique Crunches

Stand with your left hand lifted overhead and your right hand on your waist. The core is nice and tight. You want to put your weight into one of your standing legs. The other leg is more extended out to a pointed toe. 

Bring your left knee and left elbow to meet each other. Stretch out and repeat. Do it slowly to fully stimulate your obliques. Try not to let your lifted feet touch the ground. Exhale when crunching, and inhale when stretching out. 

You’re going to take a deep breath in exhale as you crunch up and bring your knee to your elbow. And you’re going to reach a little stretch through your leg and crunch. Speed this up.

You want to make sure that your standing position is nice and planted so you don’t lose your balance. Perform it with another side.

4. Side Oblique Crunch 

The first thing you’re going to do is get on the floor. Use an exercise mat for this. To perform the side oblique crunch properly, you need to lie on your side and then you’re going to be bending the spine. 

What you want to do is put your legs on top of each other. Keep your knees bent to be able to stabilize yourself. Also, make sure you maintain a neutral spine.

Put your hand behind your head. You’re not pulling your neck, you just want to place it there so that when you do the exercise you get more of a stretch. You’re going to crunch.

5. Oblique Cable Crunches

First of all, you’re going to use the cable machine with the pulley. You’re going to stand away from the machine so you’ve got a little bit of movement. You’re going to lock that into place so that your arms are not moving you. 

The oblique cable crunches exercise is not a big movement. Your elbow is crunching down towards your side. You want to come back up so that your shoulders are level. And then you’re simply just crunching your elbow down as far as you can move and then back up again.

Performing the oblique cable crunches, you’re really engaging the transversus abdominis and your full core. Make sure that everything’s just held tight in the nice isometric position. 

6. Bicycle Oblique Crunches

When people do bicycle crunches a lot of times they go right to left constantly back and forward. The problem with that is you’re never giving yourself a chance to actually get the elastic component of the muscle engaged before retracting it or contracting it again. So, you’re flopping from side to side and you’re never really engaging. 

When you do your bicycle crunches, we recommend always doing two on each side. That’s going to allow you to engage the obliques in the proper way. With that, you’re going to start developing the trunk strength that you need to be able to squat and deadlift more and to be able to plank for longer. You will start getting your metabolism the way that it needs to be to burn the fat that you need to burn.

A muscular man doing oblique crunches at the gym
  • Save

Our Recommendation to Avoid Injuries

1. Perform the Oblique Crunches Consciously

The most important thing to know about doing these is what is the starting position and what moves to do. You typically want to lean forward and use your lower back muscles because these muscles are stronger. Make sure you are aware of that to avoid making that mistake. Oblique crunches exercise is a very small movement and very safe if you do it slowly and controlled.

2. Incorporate Oblique Crunches Into Your Workout Routine Properly

Do you want to tone your core or build strength and muscle mass? How can you incorporate this exercise into your routine? This depends on your fitness goals. 

We recommend incorporating your oblique training into your abdominal training because most of the exercises with a twist are going to work both your abdominals and your obliques at the exact same time. So, it’s a lot more efficient than just trying to focus on obliques.

Oblique Crunches: FAQs

Are oblique crunches good?

If you are looking to build strong core muscles, oblique crunches are a wonderful and effective exercise for you.

Are oblique crunches good for abs?

This basic exercise helps target the obliques and abdominal muscles. It tones them up and gets them stronger. This brilliant core exercise will also help you have better posture and overall better health.

Share via
Copy link