Forget sit-ups — this standing ab exercise targets your obliques and boosts your balance

(Image credit: Getty Images)

We’ve said it before and we’ll say it again — when it comes to building a rock-solid core, endless sit-ups and planks alone won’t do it.

Not only does switching things up help you beat boredom, but it’ll also help you engage different muscles to strengthen your entire core. Five different muscles make up the abdominals, so mixing up your ab workouts ensures that you’re targeting all of them.

One easy way to immediately switch things up is to stand up. Standing ab workouts normally involve more of a full-body workout than lying down, as you have to engage your leg muscles and glutes to stay standing.

How to do a standing oblique crunch

As you’ll read below, I mixed up the different variations of oblique crunches over the week, but let’s start with the basics. Here’s how to do a simple oblique crunch:

Start by standing tall with your feet a little wider than hip-width apart. Engage your core, thinking about sucking your belly button into your spine.
Place your hands by your temples, with your elbows pointing out to the side.
Lift your left knee, and at the same time, bend at your waist to touch your left elbow towards your knee. Move slowly and with control.
Pause in the crunch, before slowly returning to your starting position.

an illo of a woman doing a standing oblique crunch — (Image credit: Shutterstock)

The key with standing oblique crunches is to move slowly and with control. The movement in this exercise comes from your core, not your arms and legs, so ensure it stays engaged throughout.

As always, if you’re new to exercise, or you’re returning to exercise following an injury or pregnancy, it’s always a good idea to check with a personal trainer before adding new exercises to your routine, to ensure you’re not putting yourself at risk of injury.

I did standing oblique crunches — here’s what happened

Ready to torch your obliques? I added this simple standing ab exercise to my routine for a week. Here’s how I got on.

I added twists and resistance bands to up the ante

The beauty of the standing oblique crunch is that you can easily increase the intensity of the exercise, or just mix things up, by adding extra equipment, or a twist. On day two of the challenge I opted for an oblique crunch twist, touching my right elbow to my right knee to work into my deeper core muscles, and really challenge my balance.

On day three, I added one of the best resistance bands to the equation. To do this, I put a small loop band around the toes of the bending leg, stepping on the other end of the band with my standing leg.

Every knee lift against the band increased the intensity on my lower body, and forced my standing leg to work even harder against the resistance.

Finally, towards the end of the week, I used a set of the best adjustable dumbbells, holding a dumbbell in each hand, with a 90-degree bend in my elbow, and completing the oblique crunch from there. This increased the upper-body burn with the move.

I felt this one in my obliques

The oblique muscles run along the side of your torso. You have internal and external obliques. Your oblique muscles control the stabilization and rotation of your torso, allowing you to twist from side to side, so are essential in everyday tasks like standing up and sitting down, as well as in sports like tennis and padel that involve twisting your body.

After a week, I felt this exercise in my obliques, especially with the extra resistance.

I didn’t notice any difference in my abs, but learned this important lesson

Of course, a week of crunches isn’t enough to see any physical difference in my body — visible abs are the result of a low body fat percentage, not ab workouts alone. That said, these oblique crunches highlighted how unbalanced I was on my left side.

Having one weaker side of the body is normal — especially if, like me, you find yourself carting a toddler around on one hip more than the other.

As a runner, however, this imbalance could easily lead to injury, so I was grateful to learn how much more work I needed to do on my left. Again, this won’t be an easy fix, but as I return to marathon training and strength work post-partum, it’ll be an essential part of my training routine.

More from Tom's Guide

See more Wellness How-Tos

Jane McGuire is Tom's Guide's Fitness editor, which means she looks after everything fitness related - from running gear to yoga mats. An avid runner, Jane has tested and reviewed fitness products for the past five years, so knows what to look for when finding a good running watch or a pair of shorts with pockets big enough for your smartphone. When she's not pounding the pavements, you'll find Jane striding round the Surrey Hills, taking far too many photos of her puppy.