Check Out the Biggest Celeb Fitness Transformations of 2021

Shay Mitchell, Megan Thee Stallion Jessie James Decker and more stars have shared the results of their hard work in the gym and we're celebrating their transformations on National Fitness Day.

By Tierney Bricker May 01, 2021 10:00 AMTags
Watch: Jessica Simpson Proves She's a Fitness Warrior

These celebrities, they can be your motivation.

It seems fitting that National Fitness Day would fall on May 1, just ahead of the summer season. Many people are likely ramping up their workouts as the temps continue to rise, including your favorite stars.

Kylie Jenner has been sharing her fitness routine with her Instagram followers, while Tiffany HaddishMegan Thee Stallion and Shay Mitchell have revealed the results of their respective workout challenges. To borrow a phrase from Haddish, these ladies are definitely ready!

And it's not just the ladies who are up in the gym just working on their fitness: Dwayne "The Rock" Johnson and Noah Cetineo have gotten into superhero shape for their new movie, while Luke Evans and Nolan Gould committed to seeing results while quarantining. 

Plus, Justin Timberlake and Mike "The Miz" Mizanin have also detailed their journeys on social media, sharing their impressive results, and Jessie James Decker has been providing lifestyle tips for her followers. 

photos
Need Some Fitspo? Stars' Favorite Workouts Revealed

Let's celebrate the biggest celeb fitness transformations of the year so far...

Noah Centineo

Peter Kavinsky, is that you?!

The star from the To All the Boys franchise appeared on the fitness Instagram profile of personal trainer Kirk Myers putting in work at the gym, and the gains were definitely showing in March.

The 24-year-old heartthrob has bulging muscles in preparation for his upcoming role as Albert Rothstein, a.k.a. Atom Smasher, in the DC Extended Universe's Black Adam.

During an interview with Australian radio show Smallzy's Surgery, Centineo explained how he bulked up to keep in step with the movie's star—Dwayne Johnson—by increasing his daily calorie intake to over 6,000.

"Last time I gained, I was eating 6,500 calories a day," he recalled, "but this time will not be as bad." At one point, he noted beginning his days with 12 eggs, steak, potatoes and a couple bowls of oatmeal.

Due to the ongoing coronavirus pandemic, the film's production was paused, which gave Centineo added time for his high-intensity workouts, two hours every day to be exact.

Dwayne "The Rock" Johnson

Lesson: Superheroes never skip leg day.

Weeks after his Black Adam co-star Noah Centineo showed off his own impressive transformation, Johnson invited his Instagram followers into his prep for the upcoming DC Comics film by posting a jawdropping photo from one of his gym sessions.

"Black Adam ready," the former wrestler wrote in the caption. "It's always the work we quietly put in when no one is watching that changes the game. Grateful for the grind (and the face of my Warrior Spirit always watching my back.)"

He added that "production kicks off this week," which explains why Johnson, whose already known for his muscular frame, was pulling out all the stops for his workouts.

Kylie Jenner

The Keeping Up With the Kardashians star is looking forward to a hot girl summer.

Jenner has been flaunting her figure with wildly fun and daring fashion ensembles. From rocking a red hot, sheer bodysuit to channeling Sharon Stone from the '90s thriller Basic Instinct, the Kylie Cosmetics founder continues to turn heads with her style statements.

And while the 23-year-old beauty mogul is looking fit as ever, a source told E! News that she has even more goals to achieve over the next few months.

"Kylie is determined now more than ever to get toned for summer," the insider shared in March. "She's fully into fitness and health."

The source continued, "She prefers doing outdoor workouts because it's more distracting and feels nice to be in nature."

Shay Mitchell

This Pretty Little Liar put in the work and she's not keeping it a secret. 

Following a four-week fitness journey with the Openfit program, the You actress revealed her transformation by sharing a side-by-side photo of herself on Instagram. 

"2020 was the year of searching for something to make us feel good," Mitchell wrote. "Not even good…to feel fine. Feel 'normal… For me that came in the form of comfort food, comfort clothes and throwing my fitness routine out the window."

So the 34-year-old partnered with the workout company to get her "s--t together," which included working out 30 minutes a day for five days a week during the challenge. Saying she feels "more fit than I have in a long time," Mitchell added, "I feel more healthy, energetic and engaged…which makes a better me."

But it wasn't just physical benefits Mitchell, who welcomed her daughter Atlas in October 2019, experienced.

She continued, "I also learned about physical and mental self-care, and made a pact with myself that 2021 would be different. I wanted to focus on myself again, because I'm the best version of myself for Atlas—and everyone else—when I take care of myself first."

Jessie James Decker

Oh hey, Jessie!

If you are in need of fitspo right now, let the "Flip My Hair" singer's recent Instagram posts about "stepping it up" in the gym motivate you.

"The top of this year I decided to really step it up in the gym! Build more muscle, get my core in order and get stronger!" she wrote in the February Instagram caption alongside a photo of herself flexing in the mirror. "I know my core will probably never be as strong as it used to be but damn it I'm gonna try! I have goals and I'm not stopping until I'm there."

You look like you already got there and bought property to us, babe!

In April, the mother of three shared her fitness routine with her followers, revealing she works out three to four times a week and relies on low-carb fare from South Beach to fuel up for her sessions.

Megan Thee Stallion

She's been working on that body-ody-ody-ody-ody-ody-ody and is definitely ready for another hot girl summer.

The Grammy winner shared the results of her ongoing fitness journey on her Instagram in April, proving hard work definitely pays off.

"When I first started #hottiebootcamp in JANUARY to now," Megan captioned the before-and-after photo. "stay consistent hotties."

The 26-year-old has been sharing her workouts with her followers since the new year when she kicked off her Hottie Bootcamp. At the time, she noted it wasn't "necessarily a weight loss journey," but she was prioritizing her health by making tweaks to her diet, Or, as she wrote, doing some "real healthy girl s--t."

Justin Timberlake

Forget the woods, he's a man of the weight rack.

For his role in the Apple TV+ film Palmer, which he began filming in late 2019, Timberlake set a goal to gain 15 pounds...of muscle. In January, his personal trainer, Ben Bruno, posted an Instagram video of the actor and pop star strength training with a landline press, calling him a "beast."

Detailing that the 40-year-old "trained his ass off," Bruno revealed he worked out "sometimes twice a day. Justin trains constantly year-round, but once he sets a goal, he goes after it with an intense focus and effort and does whatever it takes."

Timberlake posted the same video on his Instagram page, writing, "My guy @benbrunotraining kicking my ass again! Thank you pushing me to get ready for #PALMER... and for always helping to achieve my goals for roles, tour and LIFE!!!"

Tiffany Haddish

The 41-year-old comedy star took to Instagram in January to show before-and-after photos of her body transformation.

"Before my 30day transformation and after," she wrote in part of a post promoting the 30 Day Transformation Team's fitness program. "Now #SHEREADY to build Muscle and Maybe shave my armpits#."

Haddish started the program the day after Thanksgiving on Nov. 27, though her weight loss journey had begun by then. During an Instagram Live at the time, she revealed she'd lost 40 pounds so far.

Three weeks later, Haddish told her followers she was "moving forward slowly but surely" and had shed an additional eight to 10 pounds.

Mike "The Miz" Mizanin

The Miz has been busy!

The reality star and pro wrestler shared his health journey with his 3.4 million Instagram followers on April 14, posting before-and-after photos to address his weight loss.

"The picture on the left was taken on January 8, 2021. The one on the right was taken on April 11th, 2021," he captioned the post. "I set out on a journey to not only get ripped, but to get healthier. I started at 220lbs and currently I am at 206lbs."

He continued to reveal how he achieved his impressive results, included weight training four days a week for three months and eliminating gluten, dairy and soy from his diet.

"I'm doing my best to make sure I can continue to do my job at the highest level for many years to come. This routine for 3 months has now turned into a habit I want to keep," the Miz continued. "I love the way I look and feel. There are tough days where I just want to eat like crap, and honestly, I'll indulge. I know there are no short cuts. You have to put in the work for the results you want. There is no secret drink or pill that's going to get you ripped. It takes work and lots of it."

Nolan Gould

Luke Dunphy is all grown up.

The 22-year-old actor opened up about his health journey following the end of Modern Family last year.

"I spent six months basically on vacation," Gould admitted to People. "But I feel like now it's time to kind of make a decision on where I want to go with my career, and one of the ways you can do that is by changing my look and my mindset."

Ninety-minute workouts and a major change to his diet helped shift Gould's mentality.

"I'm eating so much healthier, even though there's less of it," he said. "What I get is actually really healthy food for you: lean protein, eating as many vegetables as you want and staying away from things like soda. Nourishing the mind, body, all that. And actually, for me the biggest thing was cutting out alcohol, for me that's actually been very nice. I feel more clear-headed and have been doing as much writing as possible, being in acting class, taking all the steps I can so when the pandemic's finally over, hopefully I'll just be ready to go to work."

Luke Evans

No one work outs like Gaston!

The Beauty and the Beast actor revealed the results of his recent fitness journey in a set of unbelievable before-and-after photos he posted in March.

"8 months of work but I got there. June 2020 - February 2021." Not bad for 41 years of age, or as Evans noted, "#nearly42."

His chiseled abs (and big smile) are evidence enough of how successful his workouts had been, but he wasn't sharing any more details. "I won't bother putting statistics as the judges will only judge," Evans explained.

French Montana

The rapper showed off his impressive six-pack abs in an Instagram post highlighting his weight loss.

"NEVER UNDERESTIMATE YOURSELF," the 36-year-old captioned the before-and-after images. "don't let nobody speed up your process! LIFE'S TRAGEDIES TURN TO LIFE'S GOALS ! THANK U FOR THE MOTIVATION."

In an interview with XXL, Montana opened up about his health issues that resulted in him spending a week in the ICU in 2019.

"I had a little health scare," he explained. "I tell people all the time, 'If you don't end up in the ICU after your birthday, then it wasn't a good birthday.'"

Since waking up in the hospital on Nov. 21, 2019, Montana has been sober.

"It was just overdoing something for too long," he explained. "And, to the point where, now sober is becoming my new high."

Ethan Suplee

One year after surprising fans with his body transformation, the Remember the Titans star offered an update on his ongoing fitness journey.

"Last year I set a goal of having visible abs, here's where I got to," Suplee shared in the caption before going on to reveal his 2021 goal. "This year I would like visible obliques. It's going to be a wonderfully tough year."

In January 2020, the actor and podcast host detailed his lifelong mission to lose weight, revealing he had lost and gained at least "1,000 pounds" over the years.

Watch Daily Pop weekdays at 11 a.m., only on E!.