I did 50 chair crunches for a week — here’s what happened to my core

a photo of a woman doing a crunch on a chair
(Image credit: Shutterstock)

Here at Tom’s Guide, we love nothing more than an ab workout challenge — from dead bugs every day, to trying advanced windshield wipers, we’ve tried it all. Next up on my list was seated crunches, a seated ab exercise you can do between meetings, right from your office chair. I added it to my daily routine every single day for a week. Read on to find out what happened. 

Seated ab workouts are low-impact workouts that can be done from a chair, targeting your abdominal and core muscles. Unlike ab workouts that involve lying on your back on an exercise mat, seated ab workouts are accessible to those who can’t get down on the floor, have limited space, or simply want a workout that they can do sat from their office chair during a meeting (just remember to mute your mic!) Seated crunches, also known as chair crunches, are an excellent way to target your core if you’re working out from your chair. 

As a reminder, what works for me might not be right for you and your body. While seated ab exercises are suitable for most people, if you have suffered an injury, or have mobility issues, you might want to check with a doctor or personal trainer before adding them to your routine. Always use a stable chair, without wheels, when doing seated exercises. 

How to do a chair crunch 

Let’s start with how to do a chair crunch with perfect form:

an illo of a woman doing a chair crunch

(Image credit: Getty Images)
  • Start by sitting on the edge of your chair, with your feet flat on the floor. Your back should not be on the back of your chair.
  • Sit upright on your chair and engage your core, thinking about squeezing your belly button into your spine.
  • Lean your torso back and lift both legs off the floor with your knees bent at a 90-degree angle as if you are doing a V-sit. Your torso and thighs should make a V-shape. If this is too difficult, place your hands softly on either side of the seat.
  • Extend your legs out straight, and pause. You should feel your abs working.
  • Tuck your knees back in towards your chest, at the same time raising your torso back to a seated position, then repeat.

The key here is to move with control, so don’t be tempted to rush through your reps. Your abs should be engaged throughout, and the movement should be coming from your abdominal muscles, not your upper and lower body. Your back should also be straight throughout the workout. If you notice your lower back is arching, you should limit your range of motion, or start by sitting upright on your chair and just lifting your legs together a few inches from the floor. 

I did 50 chair crunches every day for a week — here’s what happened 

My core worked hard

I’m fairly new to seated workouts — in fact, it was only a week ago that I tried my first seated ab workout and was surprised at how hard my core worked. From the seated position, I was able to isolate my abs and I could really feel my deep core muscles — the transverse abdominal muscles — working hard as I moved through the crunches. 

I tried to add a few reps every day, and a few days in I was able to hold my hands in front of my chest, rather than gripping the chair. I found my legs got a workout too, despite moving from my core.

Most days I completed all 50 reps in one go, but on other days I’d do five sets of 10 reps, and fit them in throughout the day for a core burn. By the final few days, I grabbed one of the best adjustable dumbbells and held it with both hands to really up the ante. 

I found slowing down was key

Like a lot of the best ab exercises and Pilates moves, the key with chair crunches is to move slowly, and with control. In fact, the slower you move the better with this exercise. I often find with these week-long exercise challenges that I have a tendency to rush through the movement to get it over and done with, but I was mindful of not arching my back during this exercise. 

I actually found doing chair crunches more challenging than V-crunches on the exercise mat, perhaps because my core was working harder to stabilize my body which was a lot higher off the ground. 

I mixed these up as part of a longer chair ab workout

Now I’ve discovered the benefits of getting a quick ab workout in from my desk chair between meetings, there’s no going back. On some days, I added 50 oblique crunches and 50 bicycles to the end of this workout, and I could really feel my core had worked hard. 

Of course, there was no visible change to my mid-section after a week of crunches — it takes a lot longer to build muscle, plus, how visible your abs are depends on your overall body fat percentage, not the ab workouts you do. Stress, diet, sleep, cardio levels, and hormones can all affect your body fat percentage — here’s how to calculate your body fat percentage, and why it matters

My verdict after a week of chair crunches? These helped me work my core throughout the day, and I’ll definitely be keeping them in my routine in the future. A strong core helps you sit with better posture, and protects your spine from injury, so focusing on your abs while you’re sitting at your desk can help strengthen the muscles in your midsection. Give it a go! 

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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.