I did this 90-squat challenge in 5 minutes — here’s what happened

a photo of a woman doing a bodyweight squat
(Image credit: Getty/Oleg Breslavtsev)

Here on the Tom’s Guide fitness desk, we love nothing more than a weird workout challenge. Looking for some inspiration, I stumbled across Sweat app CEO and trainer Kayla Itsines’ 90-rep squat challenge. Squats are an excellent exercise when it comes to working the gluteus maximus, medius, and minimus, the quads, hamstrings, hip flexors, calves, and core. You can do squats using just your body weight, or up the intensity by adding one of the best resistance bands, or best adjustable dumbbells.

I often use squats as part of my workout routine, so decided to use Kayla Itsines’ 90-rep squat challenge as a workout finisher. The objective is to move as quickly as possible, while maintaining good form, and record your time as a marker of your fitness. The entire workout took me less than five minutes but reminded me how versatile the humble squat is when it comes to targeting different muscles in your lower body. 

How to do a squat? 

Let’s start with how to do the bodyweight squat with perfect form:

  • Stand with your feet hip or shoulder-width apart. You can position your feet slightly wider
  • Point your toes slightly outward at 45 degrees, or forward facing if that’s more comfortable. Engage your core
  • Bend your knees and send your hips back as if you’re sitting on a chair directly beneath you
  • As you squat down, push your knees outwards so that they track directly over your middle toes and keep the weight distributed through your feet
  • Lift your chest, keep looking straight ahead and maintain a flat back. Avoid hunching or rounding your spine
  • Lower until your thighs are parallel to the floor, keeping your knees aligned with toes, heels planted and spine neutral, then push through your heels to stand back up. 

Here’s more on how to do a squat, and the form mistakes to look out for

What is the 90-rep squat challenge 

As you might have guessed, this squat challenge involves performing nine different squat variations for ten reps. Here’s the squats on the list: 

Bodyweight squats: To do a bodyweight squat, follow the step-by-step instructions above. Be sure to engage your core and squeeze your glutes at the top of the movement. 

Sumo squat: The sumo squat involves moving your feet to a wider stance, mimicking the pose a sumo wrestler might make. To do a sumo squat, stand with your feet wider than hip-width apart, and angle your toes away from your body—aim for about 45 degrees. Look down at your knees to ensure they are still directly over your feet. Now, with your core engaged and hands loosely clasped together at chest height, push your hips back and bend at the knees to lower into a squat. Keep your back straight throughout and look forward. Continue to lower until your thighs are parallel to the floor. 

Squat pulse: To do a squat pulse, squat down and pause at the bottom of your squat. Rise up a few inches, then sink back down into the squat. Keep pulsing at the bottom of your squat, and stay low throughout — don’t let your body rise up to your starting position. 

Pop squat: A pop squat, or jump squat, will help you get your heart rate up. To do a pop squat, start with your legs wider than hip-width apart and engage your core, then squat down. At the bottom of your squat, push through the floor and explode up into a jump. Land from your jump and squat back down. 

Weighted squat: For this exercise, you’ll need some kind of weight — this might be one of the best adjustable dumbbells, a kettlebell, or a weight plate. Hold the weight in both hands at chest height. Keep your core engaged, and complete ten squats. The weight will add extra intensity. 

Double-pulse weighted squat: Keep that dumbbell in your hands, and this time, complete a double pulse at the bottom of each squat, raising a few inches, then squatting back down. Once you have completed your two pulses, push through your feet and rise back up to your starting position. 

Narrow squat: A narrow squat targets the quads more than a regular wider squat stance. For this variation, step your feet closer together, with both toes pointing forwards. From here, push your glutes back, keeping your abs engaged, and lower into a squat, before pushing through your feet and rising back to your starting position. 

Squat and oblique crunch: For this variation, start in a wider squat stance, with your hands resting on your temples, and your elbows out to the side of your body. Keeping your core engaged, squat down, and as you rise out of the squat, raise one knee up to your torso. At the same time, bring your opposite elbow across your chest to tap the knee. Keep switching sides. 

Squat to lunge: Finally, for this exercise, complete a squat, and as you push back through the floor to return to your starting position, step one leg out behind you to complete a lunge. Keep switching the leg you lunge on. 

I did this 90-rep squat challenge — here’s what I learned 

This 90-rep squat challenge took me just under five minutes to complete, but it reminded me just how versatile the squat exercise can be. I found some variations really worked my glutes harder than others — pop squats, I’m looking at you, whereas switching to a narrow stance really forced my quads to work hard. I enjoyed the variation of the challenge and could feel it in my lower body 90 reps later. 

As well as being an excellent lower body exercise, squats work your core hard, as your midsection has to engage to keep your torso stable as you move. In fact, one 2018 study found that core muscle activation was higher in a back squat than it was in a plank. 

A strong lower body and core is important for runners, like me, as it can help improve running form and reduce injuries. The glutes are the largest and strongest muscle in the body, but many runners tend not to use them on the run, so working on my glute strength will hopefully pay off in my next race. I’ll definitely be repeating this squat challenge in the future. 

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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.