I did this standing ab exercise every day for a week — here’s what happened

a photo of a woman on an exercise mat holding a dumbbell
(Image credit: Shutterstock)

As a fitness editor, I’m no stranger to a workout challenge. Stick around on Tom’s Guide long enough, you’ll realize that I say yes to just about every weird and wonderful fitness challenge we think up in our planning meetings. From doing 100 single-arm clean and presses a day for a week, to trying Lily James’ 600-rep ab workout, I’ve tried it all, and on my list this week was standing dumbbell side bends. 

This exercise is often included in standing ab workouts and is sometimes called an oblique bend. To do a dumbbell side bend, start by standing with your feet hip-distance apart, and with one of the best adjustable dumbbells in one hand, resting against the thigh.

Next you engage your core, and bend at your waist, lowering the dumbbell down along your leg, towards the floor. Then engage your oblique muscles on the opposite side to the dumbbell to raise your torso back to your starting position. Repeat for the desired number of reps, before switching sides.

an illo of a woman doing a dumbbell side bend

(Image credit: Shutterstock)

Read on to find out what happened when I added this exercise to my ab workouts for a week, and why I don’t recommend it. As a reminder, what works for me might not be right for you and your body, and if you’re new to an exercise, or returning to exercise following an injury, it’s a good idea to ask a personal trainer to check your form before adding weight, or reps.

I did this standing ab exercise every day for a week — here’s why I don’t recommend it

Like your fitness guinea pig — if guinea pigs wore lycra — I embarked on this challenge, keen to learn more about this exercise. It’s not one I often included in my ab workouts or strength sessions, so I can’t say I was all too familiar with the move. Tutorials told me not to be afraid to reach for a heavier weight, so off I went. Here’s what happened: 

After day one, my back felt stiff

As I’ve mentioned in previous workout stories, I suffer from sciatica following a horse riding accident in my teens. I often have to be mindful when working my abs, ensuring that my lower back stays pressed into the floor to avoid putting too much pressure on my spine. For the sake of this article, I’d planned on doing 50 reps on each side, 100 reps in total each day. Yet after day one, my lower back felt incredibly stiff. The following day I did 25 reps on each side, but to no avail; I could definitely feel pinching and stiffness in my back. 

A quick Google search told me I wasn’t alone — often personal trainers don’t recommend dumbbell side bends, as if you lift too heavy, the dumbbell can pull you into an excessive range of motion. Plus, if you do the exercise too often, you can put pressure on the spine, which causes the nerves to pinch. 

I didn’t feel I was really working my obliques

Another reason I decided to abandon this challenge after two days? I couldn’t really feel it in my oblique muscles. I do a lot of Pilates, and have done my fair share of ab challenges — when I did 100 dead bugs a day for a week, it hurt to laugh, but even when really thinking about my abs during the move, I couldn’t really feel them working. My hips, yes, my obliques, no. 

After a quick chat with a personal trainer, he told me that if I wanted to work my obliques, there were much better exercises out there, that would be much kinder on my back, and not put me at risk of injury. 

I realized there were better oblique exercises out there

So, what should I swap the side bends out for? Side planks, Pallof presses, and bird dogs. Read what happened when two Tom’s Guide fitness writers did 50 Pallof presses every day, and 50 bird dogs every day for a week

Seconds into my first side plank, with my feet stacked on top of each other and my core engaged (here’s more on how to do a side plank with perfect form), I was shaking. I could feel my entire core working to keep my body stable, and really had to work hard to hold the move for 40 seconds on each side. To up the ante, I added side planks on a Bosu ball as a finisher to my next strength session — in a word, ouch. 

an illustration of a woman doing a side plank

(Image credit: Shutterstock)

The lesson learned here? Sometimes an exercise just won’t be right for your body, whether that’s due to an old injury, or a weakness or tightness. If something doesn’t feel right, it’s always a good idea to check with your doctor, or a personal trainer before persisting — not all soreness is DOMs, and if in doubt, stop, and swap to a simpler exercise you know you can do with perfect form. 

Looking for more workout inspiration? Here's what happened when we did 50 glute bridges a day for a week also, 100 dead bugs a day for a week and did 30 sit-ups a day for 30 days. We've also hand-picked the best workout apps to download right now, and the best gym bags to carry back and forth.

Jane McGuire
Fitness editor

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.