I just tried this 15-minute abs workout with a million views — here’s what happened

Caroline Girvan abs workout — (Image credit: Caroline Girvan/YouTube)

The world is hardly short on abs workouts right now, but the 15-minute crunch abs workout blows many of them out of the water with its simplicity. Here’s how.

This abs workout comes from Caroline Girvan. I have tried Girvan’s videos before using this dumbbell abs workout, and as her work continues to rake in millions of views, my interest continues to pique. Her 15-minute core blaster targets your upper abs through a challenging series of crunch exercises.

Like some of her other workouts, this one has 15 no-repeat exercises and zero equipment, so you just need one of the best yoga mats to roll out. It follows a 45-second work and 15-second rest format and flows like an EMOM (every minute on the minute).

The best ab exercises should work all the muscles in your core, but in the sit-ups vs crunches debate, for me, the crunch comes out on top for upper ab engagement. As a caveat, anyone who is a crunch novice or suffers from lower back pain should consult a qualified medical professional before undertaking this workout.

If it’s a hard pass, other bodyweight workouts I love include Chris Hemsworth’s 200-rep bodyweight workout and the 8 best Pilates exercises that target your core. It’s time to find out what happened when I crunched my way to stronger abs using the 15-minute crunch abs workout.

Watch the 15-minute crunch abs workout

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Girvan warns, “if you are new to crunches, you can place your hands behind your head to provide support.” She also warns against straining and jolting as the exercises should be smooth, slow and controlled, and you should also look ahead rather than towards the floor or ceiling.

The exercises are all pretty simple but intensity comes from high reps (you accumulate a lot of them during this abs workout) and slow-tempo movement. I’ve spoken about the benefits of time under tension techniques before — it means performing an exercise with a slow tempo to increase the time your muscle is contracting.

In theory, great. Some research — like this study published in the Journal of Physiology — somewhat agrees, but it appears TUT alone isn’t going to do much unless coupled with high load, high reps, or working to fatigue. However, it is still useful if you want to diversify your workouts, up the intensity, or don't have any equipment.

While integrating a variety of core-related functional exercises into your core workouts is beneficial for improving overall strength and stability, a study by PLOS found that isolation core exercises (like the crunch) elicit better improvements to muscle activation and hypertrophy (muscle growth) — at least initially.

I tried this 15-minute crunch abs workout — here’s what happened to my abs

Could I crunch my way to stronger abs? Probably, but I would likely hit boredom first. Don’t get me wrong: This is a creative workout, and finding 15 ways to perform a crunch takes some doing. But (in my opinion), you’ll build better overall functional core strength using a variety of the best core exercises — and with a reduced risk to your neck and lower back.

If you don’t have back pain, I encourage integrating crunches into your abs workout, but unless you tack this crunch abs workout on as a finisher, I don’t see the benefit of repeating it in isolation — other than to improve your crunch game, of course.

This is not the workout for sore back muscles or those new to crunches, but you can relieve some tension by keeping your gaze straight ahead, placing your hands on the floor (especially during the reverse plank) and avoiding hyperflexion in your neck.

Woman performing a crunch with her knees up at 90 degrees — (Image credit: Getty images/ unknown)

That said, I enjoyed trying it out, and it blows many other crunch workouts out of the water. Tempo and high reps are the subtle and clever killers here, and I struck up a core-scorching burn in my abs early on. I was also shaking my way through the end reps while cursing Girvan for only offering 15 seconds of respite.

While I might tuck this one away somewhere in my bookmarks, it shows you don’t need equipment to work your core to fatigue, and you get a hit of oblique work in this workout, too.

If you’re looking for a functional strength builder, this ab kettlebell workout does just that in 15-minutes, and I recently tried this bodyweight Pilates ab workout, too. This standing abs workout could also be a tonic for problematic lower backs.

Sam Hopes is a level 3 qualified trainer, a level 2 Reiki practitioner and fitness editor at Tom's Guide. She is also currently undertaking her Yoga For Athletes training course.

Sam has written for various fitness brands and websites over the years and has experience across brands at Future, such as Live Science, Fit&Well, Coach, and T3.

Having coached at fitness studios like F45 and Virgin Active and personal trained, Sam now primarily teaches outdoor bootcamps, bodyweight, calisthenics and kettlebells.

She also coaches mobility and flexibility classes several times a week and believes that true strength comes from a holistic approach to training your body.

Sam has completed two mixed doubles Hyrox competitions in London and the Netherlands and finished her first doubles attempt in 1:11.