Learn how a powerlifter-turned-therapist turned spreadsheets and setbacks into Rebuild Stronger, and relationship-first coaching business redefining rehab and performance. 

In this episode of The Business of Coaching, strength coach and physical therapist John Flagg shared his compelling journey from a Penn State grad student experimenting in the training room to the founder of Rebuild Stronger, a thriving online coaching business blending rehab and performance. With over 15 years in the strength world as a coach and lifter (not to mention a 2,000+ lb. powerlifting total), John’s philosophy is simple yet powerful: rehab and training are on the same spectrum.

The Origin of Rebuild Stronger

Rebuild Stronger was born not out of a business plan, but out of necessity. Two of John’s long-time clients—his younger brother and a local athletic trainer—were relocating but did not want to stop working with him. So he improvised: spreadsheets, YouTube videos, email check-ins. A few more injured athletes followed, and a grassroots business began to take root. Despite being fully online, John’s earliest clients were local, drawn in through word of mouth, meets, and gym connections.

Eventually, John took the leap to leave a secure position in a physical therapy clinic and go all-in on his business. His only regret? “I wish I had done it sooner.”

Relationship Over Revenue

John says that Rebuild Stronger was not built with profit in mind—it was built on relationships. He has built a deep community with his clients. That same approach carries over into his philosophy on marketing and social media: The first word in “social media” is social. “Be a real person. Build real relationships.”

He argues that genuine connections—online or in person—are still the best marketing tool in the modern coaching world.

Rehab Meets Performance

Perhaps John’s most distinctive contribution is his approach to injury recovery. Drawing on his own experience as a high-level powerlifter, he saw firsthand how performance and rehab could coexist. If an athlete’s knee hurt, they did not stop training—they shifted focus and pushed the bench press. Do not underestimate the psychological aspect of not feeling broken, of still being an athlete.

This mindset reframes setbacks as opportunities and prevents injuries from becoming identity crises. Even general population clients benefit from this fusion. Everyone deals with injuries and issues as they age, but learning how to manage those and still make meaningful progress is better than the decline that comes with not moving at all.

Lessons in Pricing and Tech

Building a sustainable business did not come without stumbles. One big lesson: do not race to the bottom on pricing. Lower prices attracted less committed clients, hampered service quality, and stretched the team too thin. Raising prices did not just stabilize the business—it brought in more motivated clients who bought in to the value and did the work.

Another major evolution was in tech. From clunky spreadsheets and YouTube uploads to modern coaching platforms, John learned to embrace innovation. Switching to TurnKey Coach, a platform that supports rich client interaction, proved to be a game-changer. Like any worthwhile technology investment, it enables John to more effortlessly deliver the experience and service his clients know and love him for.

Failing Forward

John sees failure not as a stop sign but as a stepping stone. “By the time you have tried once, I have failed ten times—and learned ten times more.” That mindset helped him grow from a solo operation into a team-based business built on excellence, feedback, and evolution.

John Flagg’s story is proof that blending science with experience, rehab with performance, and business with heart is not just possible—it is powerful. Build relationships, trust your gut, and do not fear failure.

PS - Want to scale your coaching business without burning out? Schedule a 1:1 call: https://app.reclaim.ai/m/mac-barbell-logic/turnkey-coach-team-call

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