Owner & Head Coach

Sandy Martz.

Long before Flow Strength existed, Sandy was happiest outside—riding horses, exploring the woods, or finding any excuse to be moving. She grew up with a deep love for horses, and at twelve years old she got her first horse, a buckskin Quarter Horse gelding named Joey. Caring for him taught her responsibility, patience, consistency, and the satisfaction that comes from putting in the work every single day. As she got older, she continued competing in horse shows, where she developed an even greater appreciation for discipline, movement, and mindset—lessons that continue to shape the way she coaches today.

Sandy’s fitness journey didn’t really begin until after the birth of her second daughter, Maya.

Like so many moms, she wasn’t trying to become an athlete—she was simply looking to feel more like herself. It started with a single mile run while pushing a double stroller with her daughters, who were just two years old and six months old at the time. One mile became another, and before long, running had become a regular part of her life.

Around that same time, she discovered another outlet at the local YMCA. Group fitness classes—including cardio kickboxing, strength training, and yoga—became more than just workouts. They became a place to recharge, build confidence, and reconnect with herself. It was there that Sandy realized how transformative movement could be, not just physically, but mentally as well.

In 2018, while training at a local gym, Sandy decided to become a certified personal trainer. Taking that leap changed her life. Looking back, she often says there would be no Flow Strength without Fortitude Fitness and the encouragement of her trainer. It was there that she discovered not only a love for fitness, but a passion for coaching people.

What started as coaching cardio kickboxing classes twice a week quickly grew into something much bigger.

She realized that group fitness was where she truly felt at home. There is something special about bringing people together, creating an environment where everyone works toward their own personal goals while encouraging one another, and watching people accomplish things they once thought were impossible.

As Sandy grew as a coach, so did the opportunities. Before long, she was helping athletes prepare for local Brazilian Jiu Jitsu tournaments, superfights, and eventually major competitions like the IBJJF Pan-Am Championships and the IBJJF World Championships. Through those experiences, she realized something important: whether someone is training for competition, preparing for a marathon, recovering from an injury, or simply wanting to keep up with their kids or grandkids, the goal is really the same.

Fitness is freedom.

Sandy believes strength is about far more than building muscle—it’s about building the freedom and confidence to say yes to life’s adventures. She often says that building muscle is like putting money in the bank for your future, allowing you to keep doing the things you love for years to come.

That’s the foundation Flow Strength was built on.

Sandy believes most people don’t need another generic workout plan or the latest fitness trend. They need a coach who meets them where they are, a place that feels like home, and a community that feels like friends. They need someone who watches how they move, makes adjustments in real time, and helps them build confidence one session at a time.

The greatest part of coaching, for Sandy, is watching someone discover they’re capable of more than they ever believed. Whether it’s getting their first box jump, setting a personal record on a lift, running their first 5K, signing up for a race they never thought they could finish, stepping onto the mats for their first Brazilian Jiu Jitsu tournament, or tackling a mountain climb they’ve always dreamed about, those moments are why she coaches.

Outside the gym, Sandy enjoys running, training Brazilian Jiu Jitsu, hiking, camping, traveling with her family, and making the most of everything Maine has to offer. Those aren’t accomplishments to her—they’re simply the things she loves to do and the reason she believes being strong matters. Fitness should make life bigger, not become your whole life.

Sandy is proud to be a wife to her husband, Hayden, and a mom to their three children—Hayleigh, Maya, and Jacoby. Together they own Flow Brazilian Jiu Jitsu, where Sandy teaches women’s and children’s classes and occasionally steps onto the competition mats herself.

She’s also a lifelong dog lover. Their Boston Terrier, Gracie, is never far from her side, and Ellie, their rescued Frenchie mix, has been the perfect addition to the family. Her heart dog, Lexi, was her loyal running partner and best friend for fourteen years. Losing Lexi in 2025 left a hole that will never completely heal, but she remains a daily reminder to appreciate the simple things—fresh air, long walks, and the people and dogs we get to share life with.

Today, Flow Strength is the kind of place Sandy always hoped to create—a welcoming gym where beginners feel comfortable walking through the door, experienced athletes continue to be challenged, and everyone is encouraged to become stronger than they were yesterday.