Shelly Mattes Is Counting Her Blessings

Leading up to her STRONG cover shoot, Shelly Mattes had a lot on her plate, to say the least. Since her last visit in late 2024, when she posed alongside her friend and fitness inspiration Linda Mitchell, Shelly’s schedule has been packed to the brim with matters both personal and professional—not to mention preparation for a return to the fitness competition stage.

But Shelly? Cool as a cucumber. Positively radiating calmness, in fact.

“We just dropped off Kennedy (at Harvard Law School),” she explained when speaking to STRONG this August, referring to her eldest who had just returned to university. “She graduated from Princeton University, then spent the last two years working for Legal Aid in New York City, and now she’s at Harvard in Cambridge, Massachusetts.” Gushing about both Kennedy and her youngest daughter, Margo—currently a junior at Princeton majoring in political science and Spanish, all while rowing for the Princeton crew team—Shelly is every inch the proud, doting parent, listing her children’s accomplishments with pride but not a hint of ego. No matter the direction of conversation, she always ensures that the praise for her daughters’ post-secondary careers and keen interest in the U.S. justice system is credited to their intellect and work ethic, not her parenting.

Of course, some of the credit for Kennedy’s and Margo’s success can also be attributed to Shelly and her guiding hand. Raising them with compassion for those around them, including early trips to soup kitchens and other events where they gave back to the community, and showing them the power in helping others through her work as a court-appointed special advocate for children were important aspects of their upbringing. In her advocacy role, Shelly works with kids whose parents are caught up in the legal system, helping local families heal in the face of unimaginable difficulties, while championing kids who would otherwise be forgotten reach their full potential. For instance, a recent case has found her assisting a boy and his siblings in achieving their dream of going to college through a lottery-based program that will improve their odds of being accepted. 

“Their chances have greatly increased, because now they’re around people who are lifting them up,” says the 55-year-old. “They’re surrounded by coaches and teachers and people that are keeping an eye on them; all the things that their dad didn’t get and wasn’t exposed to but wanted for them.”

And for every moment of hope Shelly provides, she receives a priceless reward in return: the satisfaction of knowing she’s doing everything she can to affect positive change in the world.

“I do love it,” she shares. “I feel like we’re all supposed to give back, and this is my way.”

Role Model Mode

It’s clear that Shelly has been leading her brood by example, spiritually and emotionally. But her influence doesn’t stop there, as it’s plain her passion for movement has trickled down to her kin.

“From the very beginning, I’ve always worked out and played sports,” she notes. “So when my daughters were little, I took them to the gym with me. They’ve both grown up in that environment, and they’ve both been very active in sports: swimming, field hockey, basketball, running, cross-country, all of that.”

Their early years as athletes bestowed Shelly’s daughters not just with hand-eye coordination and long-lasting friendships but an appreciation for their bodies that she sees in them to this day. Exercise to them, she explains, is a tool, not a means to an end. 

“Skinny isn’t the goal; healthy and strong is the goal.”

“I’ve always talked to them about it; that it’s more important to be healthy than thin,” she says. “Skinny isn’t the goal; healthy and strong is the goal. I put that into them at a young age because you look around and all these young girls are trying to be skinny. Kennedy and Margo have really adopted that strength mindset, and they’re very proud of it.”

With Shelly, it’s obviously not just a “do as I say” approach to fostering a healthy body image in her daughters. Growing up, she felt uncomfortable in her body (“I towered over the teachers,” she recalls), and it wasn’t until she found her stride in sports that she came to terms with it. In fact, her broad shoulders, once a feature that she detested, became a powerful force on the court and field. Eventually, she began training them to enhance her performance, and soon enough, she was hooked. “The insecurity went away, and I realized it’s great to be strong,” she shares.

These days, Shelly’s only too eager to lace up and run alongside Kennedy, or meet up with Margo at the gym to get in a lifting session. For the Mattes’, “the family that sweats together, stays together,” Shelly summarizes with a laugh. “That’s my motto.”

Positivity in the Face of Tragedy

Like many others, Shelly’s been on a health journey that has had its peaks and valleys. When Kennedy was still very young, Shelly was diagnosed with thyroid cancer, which sent their world into a spiral. Even worse: the discovery coincided with September 11, making her NYC-based treatment at Memorial Sloan Kettering difficult, but not impossible, to complete. “It was a really, really hard time,” she admits. Luckily, she pulled through with the help of doctors and the steadfast support of her husband, John. And in the wake of her recovery, they decided to take another leap of faith. 

“I didn’t know I wanted another baby till I found out I had cancer,” she admits. “I was like, ‘I want Kennedy to have a sibling.’ If anything happened to us, she would have another partner, a best friend.” And that’s how Margo came to be—and as mom had predicted, the two girls became absolutely inseparable. 

Another dynamic duo in the family unit is, of course, Shelly and John, who have been together for 33 love-filled years. (“One of our first dates was to the gym,” she recalls.) Seasoned travelers and the epitome of each other’s rock, the couple also shares a successful business, leading teams at the medical imaging centers they jointly own. This focus on health in their professional life isn’t coincidental, as it hits close to home for both of them. Shelly tells STRONG that for the past 10 years John has been fighting his own courageous battle against an autoimmune disorder that’s treated like cancer by oncologists. Thankfully, after a number of experimental treatments—and a lot of patience—he was declared disease-free earlier this year, for the first time in nearly a decade. 

“It’s so painful,” Shelly shares. “And it’s been such a struggle.” John, being very well-read and extremely educated, researched what scientists in both the U.S. and Europe were doing to combat the specific type of autoimmune disease he was diagnosed with. In a stroke of luck, John was selected as the ninth person with AL amyloidosis to receive CAR T-cell therapy at Tufts Medical Center in Boston, which oncologists have pinpointed as extraordinarily effective in the fight against cancers, as well as bone marrow disorders. After a 10-day stint at the hospital this May, he was given a clean bill of health. 

“He’s still recovering, but he’s doing great,” Shelly says. “He was fortunate enough to be in the clinical trial, but pretty soon it will hopefully be ready for everybody.” As a sort of joint celebration, both for John’s successful recovery and her first solo STRONG cover, the two will be jetting off on a well-deserved vacation to Miami to mark all they have accomplished and all they are thankful for. And as one might expect, they’ll still carve out plenty of time to be active while away from home—which Shelly stresses is a non-negotiable. 

“It used to be that you could do whatever you want in your twenties,” she says, speaking of one’s decision to exercise—or not. “You could pretty much do whatever you want in your thirties. But since I was sick, I know I never want that to happen again.”

In her fifties, Shelly has more energy and zest for life than people decades younger. And you can bet she is going to continue spreading the word that, no matter your stage in life, there’s no end to what you can accomplish. 

As the interview came to a close, when Shelly was asked whether “50 is the new 30,” she paused before responding.

“I would probably say that’s an individual thing,” she said carefully, “because there are people that are 50 and feel like they’re 30, but there are people who are 50 who feel like they’re 60. I still feel like I’m 30! 

“It’s a state of mind, really. But I think if you want to feel younger, do all the things that will help you feel younger: work out, drink water, be around positive, inspiring people. Try to change your mindset as much as you can. The best part is, in the end, it’ll help you feel grateful for what you have.”