Meet the Coach Behind Flow Strength.

Head Coach & Owner

Sandy Martz.

Sandy didn’t set out to run a gym — she set out to keep training, and to get better at explaining what she’d learned along the way. Years spent coaching strength and HIIT in the gym, and years spent on the mat, taught her that most people don’t need more information about fitness; they need someone in the room who can see what their body is actually doing and adjust it in real time. That’s the coach she built Flow Strength around.

Her own training runs on more than one track. In the gym, she trains the same way she coaches — structured programming built on progressive overload, recovery, and consistency, mixed with the higher-effort conditioning of HIIT. On the mat, she trains Brazilian Jiu Jitsu, where she holds a brown belt: a rank earned only through years of live training against resisting opponents, not something you can study for. And outside the gym, the same consistency shows up on the road and the trail — she’s completed a marathon and multiple half marathons, and she’s climbed Mount Katahdin, including the Knife Edge. All of it shows up in how she coaches — technique first, patience with the process, and a habit of noticing the small adjustment that makes a hard movement click.

Sandy holds four credentials from the ISSA (International Sports Sciences Association), one of the most widely recognized certifying bodies in the fitness industry, plus a CF Level 1 coaching certification. In practice, here’s what that means in the room every morning: her ISSA Certified Personal Trainer credential covers exercise science and safe program design — building a plan around your body instead of handing you a generic template. Her ISSA Bodybuilding Coach certification adds structured strength and physique progression — how to load, sequence, and recover so progress keeps coming instead of stalling out. Her ISSA Group Fitness Coach credential is specifically about running a room — cueing a class full of different bodies and experience levels at once, so nobody gets lost and nobody gets hurt. And her CF Level 1 (CF-L1) rounds it out — the foundational CF Level 1 coaching certification, focused on functional movement standards and scaling a workout up or down without changing what it’s training.

Flow Strength exists because Rockland needed a gym built around people, not machines and mirrors. Sandy built it as a place where a first-timer and a five-year member train side by side, where the coaching stays personal because the class sizes stay small, and where the goal is always the same — get a little stronger than you were last week, together.

Personal training at Flow Strength is built for one person at a time — your schedule, your history, whatever you’re carrying into the gym that day. Some people come in chasing a number on the bar. Just as many come in because they want to keep carrying their own groceries, get up off the floor without thinking about it, and stay strong enough to keep doing the things they love, for the long haul. That’s not a different kind of training — it’s the same strength training, programmed around what your body needs right now and built to keep working for years, not just weeks. If that sounds like you, one-on-one coaching gives you a program built entirely around your body and your goals, with Sandy adjusting it as you go.