Today we’d like to introduce you to David Fennell.
Hi David, so excited to have you with us today. What can you tell us about your story?
With over 15 years of industry experience and a passion shaped by his own fitness journey, David Fennell—founder of RE|DEFINE Fitness—offers Tyler residents a sustainable, personalized path to better health.
David specializes in small-group personal training focused on consistency, motivation, and injury prevention. He built RE|DEFINE to serve his clients in the best way he knows—by meeting them where they are and helping them redefine what fitness means.
Drawing on a background in functional training and physical therapy, David blends science, real-world experience, and care to help clients move better, feel stronger, and stay consistent. Perfection isn’t the goal—showing up is. Small steps, done consistently, lead to lasting change.
Would you say it’s been a smooth road, and if not what are some of the biggest challenges you’ve faced along the way?
I wouldn’t go as far as to say it was super bumpy, but it was definitely long and not straight. Looking back, it’s easy to say I was destined to be a trainer—I was the one leading workouts in high school, college, and even post-college. But it took time for me to realize that what came naturally to me was more than just a passion—it could be a career.
It wasn’t until my late twenties, after exploring other paths and working through my own ups and downs with fitness, that it finally clicked. I realized I didn’t just enjoy training—I loved helping people feel stronger, move better, and rediscover what their bodies are capable of. What started as something casual among friends became a calling, and eventually, the foundation for RE|DEFINE.
From 2013 to 2021, I experienced the most growth—personally and professionally—while working under Brent and Cassie Gallagher at Avenu Fitness in Houston, TX. It was there that my training ability truly took off, and I began shaping the kind of leader and coach I aspired to be. Their mentorship helped refine not just how I coached others, but how I carried myself in life and business.
Appreciate you sharing that. What should we know about RE|DEFINE Fitness and Lifestyle?
At RE|DEFINE Fitness, we’re challenging the idea that fitness has to be extreme, confusing, or one-size-fits-all. RE|DEFINE is a training facility built for real people living real lives—those who want to feel stronger, move better, and build lasting habits without burning out or feeling lost in a crowd.
RE|DEFINE was created with one clear mission: to help people overcome the biggest barriers to consistency in fitness—limited time, past injuries, lack of motivation, and the overwhelm that comes with trying to figure it all out alone.
We specialize in small group personal training and which allows our programs to be customized for each client’s needs, goals, and fitness level. In our small group sessions (typically 2–5 people), each client receives individualized coaching within a supportive community. It’s the best of both worlds—personalized attention and the camaraderie that keeps people coming back.
Our clients range from busy professionals and parents to retirees and weekend warriors. Many have tried large gyms or rigid programs in the past and found them unsustainable or ineffective. Others are simply looking for a welcoming, judgment-free space where they can build strength, stay consistent, and take care of their health without adding stress to their lives.
Who else deserves credit in your story?
Much of David’s growth as a trainer and leader was shaped by the mentorship of Brent and Cassie Gallagher, owners of Avenu Fitness in Houston, TX. From 2013 to 2021, he worked alongside them, learning not just how to train better—but how to lead with integrity, purpose, and a client-first mindset. Their influence laid the foundation for the vision that became RE|DEFINE.
Equally vital has been the support of his wife, Nicole Fennell—a registered dietitian, super mom, and David’s biggest cheerleader. Her encouragement, wisdom, and belief in the mission have helped bring RE|DEFINE to life in every way.
Contact Info:
- Website: https://www.redefinefitnessetx.com/
- Instagram: https://www.instagram.com/redefinefitnessetx/
- Facebook: https://www.facebook.com/profile.php?id=61573352254053
Image Credits
Lindsay Louis
Nicole Fennell
Jonathan Fennell
Madeleine Fennell
William Fennell
