The Differentiator Is CrossFit: David Fennell Goes From 550 Pounds to Strict Pull-Ups

For as long as David Fennell, 44, can remember, sports have been part of his identity. As a kid, he enjoyed football, wrestling, and basketball. But when he entered adulthood and the oil and gas industry, Fennell’s life shifted. Long hours, high stress, and unhealthy food options became the new normal. His love for movement never disappeared completely — he’d still occasionally find himself doing jiujitsu, a sport he picked up in adulthood — but the inconsistency couldn’t outweigh the battle happening quietly in the background.

“I’ve always identified as an athlete, even at my heaviest,” Fennell said. “But I never made fitness a mainstay. My work life always won out. And underneath it all, I was fighting a food addiction I didn’t fully understand.”

In a decades-long struggle to get control over his health, Fennell’s weight yo-yoed up and down as he tried to dial in his fitness and nutrition. “I don’t feel like I ever gave up,” he said. “But I didn’t connect my mental health to my food struggles.”

When he made that connection, Fennell said it was “the beginning of everything.”

Drastic Measures

At more than 550 pounds, Fennell knew change was critical, and he was willing to go to extremes to get control over his weight. He and his wife, Brianna, committed to Andy Frisella’s 75 Hard program, and together they made it through. With two workouts a day and a low-carb nutrition regimen, he dropped nearly 100 pounds in 75 days. 

“I came out energized, ready to keep going,” he remembered. 

But when COVID-19 shut down gyms later that year, old patterns crept back in, and within months, he had gained all the weight back and then some.

That spring, he faced the hard truth that he couldn’t win this battle on his own. 

“I got to a point where I had to understand that I wasn’t any different than anybody else struggling with addiction, and that ultimately, I was powerless,” he said. 

In November 2021, Fennell flew to Mexico for bariatric surgery, desperate to finally lose the weight for good. On the operating table in Puerto Vallarta, he weighed 530 pounds.

“That first year (after surgery), I didn’t touch fitness,” Fennell said. “I just focused on rebuilding my relationship with food.” 

Fennell’s focus on nutrition alone helped him shed over 250 pounds in 12 months. 

Finding CrossFit

Post-surgery, Fennell dealt with kidney stones and a hip injury that left him unable to walk without a cane. After doing some physical therapy and realizing that his lack of movement after surgery probably contributed to his hip issues, Fennell walked into his first CrossFit affiliate, not knowing his life was about to change drastically. He said CrossFit came to mind when he remembered some of the athletes he used to work with in MMA.

“I managed MMA athletes in a past life, and a few of those athletes were active in CrossFit as their primary strength and conditioning work, both in and out of fight camps,” he said. “To be honest, I had some reservations, but one thing was for certain: they all carried a ton of lean muscle mass … and I missed feeling strong. “ 

What he found when he joined CrossFit wasn’t just a workout; it was a support system like he could have never imagined.

“The community has been the linchpin of my progress,” he said. “I’ve [dropped in] to over 20 affiliates, and every single coach, every single member has impacted me. At our home gym, CrossFit Zachary, it truly feels like family.”

CrossFit became an anchor for Fennell, a place where consistency replaced motivation, and showing up became a non-negotiable. “If I relied on motivation, I’d go twice a week,” he said. “Instead, this is just who I am. This is how I silence the addiction demon on my shoulder. For a few hours, the gym buries him.”

The Fight With Food

Even with CrossFit in his routine, nutrition remained a complex battle. Early on, Fennell simply focused on eating enough to fuel his workouts. Later, he pushed calories to build strength. At times, Louisiana food culture and life changes tested him, pulling him back to old patterns.

By late 2024, he had climbed back to nearly 300 pounds. Around this time, a nagging ailment exacerbated by teenage injuries left him in a sling, forcing him to dial back his fitness routine, and the doubt started to creep back in. That’s when he sought out his doctor and began GLP-1 treatment, a decision he describes with honesty. “I’ll probably get criticized, and that’s OK,” he said. “I needed help mentally. My dedication hasn’t changed, but the medication gave me a reset I desperately needed.”

With a renewed focus, Fennell recommitted to CrossFit and his pursuit of a healthier lifestyle.

“I think that CrossFit has been the catalyst (for my weight loss and maintenance) in a plethora of ways,” Fennell added. “I don’t think it’s ‘magic’ in any way, but I think the variation in programmatic structure, the high intensity, the differences in coaching class to class, but most importantly, the community is what really drives that lasting aspect.” 

Today, Fennell keeps his nutrition simple and sustainable: whole foods, protein first, repeated weekly meals, prepped with his wife. “I don’t track. I don’t complicate it,” he said. “I focus on eating until I’m sustained, not stuffed. That’s been a game changer.”

Fennell’s Proudest Moments

Some of Fennell’s proudest achievements so far include performing strict pull-ups, a feat that has escaped him since his elementary school fitness test days, building the discipline to average nearly six days a week in the gym since January 2023, and prioritizing his mental health longer and more consistently than ever before. 

“I’ve learned to let my goals change,” Fennell said. “To stop focusing only on results, and to find beauty in the struggle. Who I am is defined in the fight, not the success.”

Embrace the Overwhelm

For anyone intimidated at the beginning of their CrossFit journey, Fennell’s advice is simple: embrace the overwhelm. “It’s healthy. It means you’re growing,” he said. “You’ll never be good at everything, and that’s OK. Find what you enjoy and lean into it.”

And never judge yourself against appearances, he added. “When I walked into my first gym, everyone looked like superheroes. I felt like I didn’t belong,” he remembered. “But the truth is, we were all insecure, all on our own paths. If I had listened to that initial judgment, I would’ve missed out on the pure privilege of being impacted by this community.”

The Road Ahead

From 550 pounds to strict pull-ups, from fighting food addiction in isolation to finding family in a CrossFit box, Fennell’s story isn’t about perfection; it’s about persistence.

“I don’t need to be as strong as I was at 17. I just want to be fit for life,” he said. “My goals evolve as my perspective changes. That’s what makes this sustainable.”

That sustainability is key for Fennell. By working with his medical team and pursuing habit change through a relentless dedication to real food and a fitness regimen that works, he’s setting himself up for long-term success that he can maintain. His journey is proof that transformation isn’t linear or easy. It’s messy, filled with setbacks, but defined by relentless forward motion, consistency, and a desire to be better than yesterday. Above all, it’s a reminder that strength is built not in the successes but in the struggles that shape us along the way.