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Kardashian Trainer Don-A-Matrix on the Sisters’ Butt Exercises: ‘There’s a Lot of Maintenance Going On’

kourtney kardashian khloe kardashian kim kardashian
WATCH WHAT HAPPENS LIVE WITH ANDY COHEN -- Pictured (l-r): Kourtney Kardashian, Khloe Kardashian and Kim Kardashian Charles Sykes/Bravo/NBCU Photo Bank via Getty Images

Every member of the Kardashian crew is into fitness. At the moment, most of the sisters take training sessions with the same pro, Don-A-Matrix — and he’s spilling all to Us Weekly on their group workouts and favorite exercises. (Hint: It’s all about the butts.)

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“As we go into the new year, there’s a lot of maintenance going on. They’re more focused on, you know, if they have any events coming up,” Don tells Us of Kourtney Kardashian, 39, Kim Kardashian, 38, and Khloé Kardashian, 34. “So right now, with this family, everybody’s fitness-crazed, and it’s really just to maintain who they are in terms of being confident.”

Don-A-Matrix attends the Wellness Your Way Festival at Duke Energy Convention Center on October 6, 2018 in Cincinnati, Ohio. Phillip Faraone/Getty Images for Wellness Your Way Festival

And of course, the body part that keeps them most confident is the famous Kardashian rear: “Oh, you know, they love having nice, flat abs and also working on the gluteus maximus, making sure your butt is nice, tight and round,” says the celebrity trainer, who has also worked with Josh Duhamel, Tyrese Gibson, Fergie and Kanye West.

As such, the L.A.-based pro has designed compound strength-training moves for the siblings that focus on the booty and thighs. “I came up with these exercises that I do and I call them my Matrix Move,” he says. “It’s more, doing time doing resistance training and cutting cardiovascular training. So doing Matrix Move, it has us focus on more than one body part at a time to allow you to be working on your butt, but also to be shaping up the thighs.”

Khloe Kardashian
Khloe Kardashian is seen on May 06, 2015 in Los Angeles, California. Bauer-Griffin/GC Images

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Even more time-saving: Don reveals the Keeping Up With the Kardashian sisters often train together! “With their schedules in their family, a lot of times it’s hard for us to go individually in the morning because we cross paths,” he continues. “So, you know, Kim will come over, Khloé obviously and Kourtney will come over and we’ll get on training as a group.” Kim also frequently works out with trainer Melissa Alcantara. Khloé, who has been focusing on healthy weight loss since welcoming her daughter, True, in April 2018, sees Gunnar Peterson too.

Don uses a technique with his clients and in his group classes called the Matrix Method, which sets up workouts as a game with four quarters. “I just do that same four quarters method and it works really good with groups of people as well,” he says. “Sometimes when the Kardashians come in, it’s like, ‘Hey, if we’ve only got 30 minutes, we have to speed things up to make sure we get the four corners in.’” Otherwise, he says, the four quarters sessions typically last 45 minutes.

Kourtney Kardashian
Kourtney Kardashian out and about in beverly hills. 17 Aug 2018 MEGA

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Another mainstay of his workouts: BODYARMOR LYTE Sports Drink. It’s “a drink with hydration that enhances your performance in working out, so it’s just, like, a natural, low-calorie drink that’s packed with a lot of electrolytes and coconut water and vitamins that help you sustain that energy level through the workout,” says the pro, who works with the brand. “I’ve incorporated it into the Matrix system.”

As for the Kardashians’ younger sisters, Kendall Jenner and Kylie Jenner, Don reveals that he worked with Kylie after she had her baby, Stormi, in February 2018 — if only briefly. “Our time ended up being really short because of all my other clients and, you know, she’s younger, so her body kind of pops back really, really easily,” he says of the 21-year-old. “We just did a few things here to kind of touch her up, but not much.”

With reporting by Emily Marcus

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