Our Coaches

Jonas Grabarnick

Owner and Head Coach
A Miami Beach native, and in the gym since 1991 when he was 15. His fitness journey started early in NMB senior high weight room (class of 92′) and led him to endurance events later in life. In 2008 he eventually found CrossFit through his lifelong friend Steve. Jonas runs the Miami Endurance program at CFNMB and the Olympic weightlifting classes. He is CrossFit Level 1, Level 1 USAW Sports Performance Coach and CrossFit Endurance Certified. Jonas tries to inspire and empower his clients every chance he gets. You can describe him as all passion and no nonsense. Jonas loves pineapple, appreciates good music, squats more than you and knows all the lines from every Arnold Schwarzenegger movie ever made.

Marston Garceau

Head Coach
Started CrossFit five years ago, continued through college, and has been competing and coaching for the past four years throughout the United States and Australia! Grew up playing Hockey, Lacrosse, and X-Country. After finding CrossFit Marston began training and coaching the members of the teams he used to be on, as well as helping his College Rugby team win their conference. He loves to talk and has absurd amounts of energy, and can usually be found screaming encouragement to his fellow members and athletes.

Eric Bohn

Currently active duty Army for 13 years and he has held positions from rifleman, machine gunner, Team Leader, Squad Leader, and Platoon Sergeant. Proud paratrooper and former Drill Sergeant. Started CrossFit three years ago in Afghanistan and has never looked back. He pursued his CrossFit Level 1 in 2015 and has a passion to coach, teach, and motivate. Grew up playing soccer, track, and rugby.


Monday6:00AM - 7:30PM
Tuesday6:00AM - 7:30PM
Wednesday6:00AM - 7:30PM
Thursday6:00AM - 7:30PM
Friday6:00AM - 7:00PM
Saturday9:00AM - 11:00AM
Sunday9:00AM - 10:00AM


keep in touch


2275 NE 164th St,

North Miami Beach, FL 33160

Phone. 305-974-5812

Email. info@crossfitnmb.com