Daniel Belli | Owner

Strength and Conditioning Coach


Daniel Belli has owned and operated Mason Street Strength and Fitness since January 2016. He earned a Bachelor of Science in Exercise Science/Physical Education at Southern Connecticut State University, he is certified in Physical Education K-12 by the State of Connecticut. Daniel has taken his experience as a collegiate football player as well as a decade in the industry to help develop and implement programs for adults and youth athletes alike. His training approach encompasses the mind and the body to provide clients with a positive experience for achieving their fitness and lifestyle goals. Daniel has helped many high school student athletes elevate their performance to allow them the opportunity to be recruited for college sports.

In addition to working with clients directly, Daniel has also held management positions, both as a Fitness Training Manager and Personal Training Director, in fitness clubs throughout Connecticut and New York. He has also coached high school football as well as directed and implemented their strength and conditioning programs.

Additional Certifications: Certified Physical Preparation Specialist (CPPS), FMS Level 1 & 2, CPR, First Aid & AED.

Kyle Marandino | Coach

Strength and Conditioning


Kyle is a Certified Strength and Conditioning Specialist (CSCS) through the NSCA. In addition, he is a Registered Strength and Conditioning Coach (RSCC), an elite certification that distinguishes individuals who have substantial experience as a strength and conditioning coach in the professional or collegiate setting.

Prior to joining Mason Street Strength, Kyle was a Strength and Conditioning Coach within the Boston Red Sox organization where he assisted in the design and implementation of the strength and conditioning program for both major league and minor league players. Earlier Kyle worked as a Football Strength and Conditioning Intern at the University of South Carolina where he assisted in all aspects of the Gamecock football strength and conditioning program as well as with track and field.Kyle has also worked with male and female athletes from a wide variety of Division 1 sports at the University of Connecticut, Quinnipiac University, and in the high school setting.

Kyle graduated from Springfield College with a BS in Applied Exercise Science.

Keith Kirwan | Coach

Strength and Conditioning


Keith Kirwan’s training begins with a plan tailored for each client. Keith brings together movement, posture, proper mechanics, injury prevention, and strength for a comprehensive, total body approach. There is no one way to be strong, so whether your goal is ligament/tendon strength, cardiovascular strength, muscular strength, postural strength, or explosive speed, Keith has a plan. It’s all about training harder and smarter to achieve success.Keith’s journey into the field of physical preparation began early. He discovered that natural athleticism wasn’t enough to stand out; to shine requires physical preparation and training. And the results quickly showed: he made tremendous improvements on the football field and in track and field. Today, Keith uses his trainer education and first-hand experience to excel as a coach, to inspire and guide others.Keith is a certified NASM Certified Personal Trainer and a CPPS Certified Physical Preparation Specialist.

Brett Parsell | Coach

Strength and Conditioning


Brett received his BS in Exercise Science from Central Connecticut State University. Prior to that he was a two sport athlete at Becker college, where he played football and lacrosse. Brett's most recent experience was that of a sports performance coach at Velocity Sports and Parisi Speed school in Westchester, NY. With over 5 years of experience in the field Brett has worked with countless athletes and many high schools and AAU programs in Fairfield and Westchester Counties. Brett is a Certified Exercise Physiologist through the American College of Sports Medicine and is CPR/ AED certified through the American Red Cross.

"After receiving several offers from facilities in Greenwich and Rye, I ultimately chose Mason Street Strength & Fitness because of the atmosphere and the coaches," Brett explains. "As soon as you walk down the stairs you know it’s time for business! As their coach, clients can expect a FUN but tough workout. I’m most looking forward to adding even more value to a facility that has helped so many reach their maximum potential, adults and young athletes alike."

Russell Howard | Coach

Strength and Conditioning


Russ played 4 years of football at SUNY Cortland. He was a two time captain and received All-American Honors his senior year.After graduation he jumped into strength and conditioning intern roles at the University of Virginia and University of Texas.He was a graduate assistant at Northern Arizona University where he assisted with Football, was the head strength coach for Men’s and Women’s Throws, Women’s Golf, and Women’s Dive.After graduating with his masters degree he began a part time Assistant role at Yale University where he assisted with Men’s Lacrosse, Football, and Field Hockey.“I look forward to taking all my experiences from the universities and applying that knowledge to the youth athletes and adults at Mason Street Strength and Fitness”

Ricky Mejia | Coach

Strength and Conditioning


Ricky received his Bachelor’s in Exercise Science with a concentration in human performance from Southern Connecticut State University in 2019. Prior to college he was a 3 sport athlete and captain for Norwalk High School. His athletic upbringing made a seamless transition to learn more about athletic performance and the human body. Before joining the team here at Mason St. Strength & Fitness he was a trainer at a physical therapist clinic specializing in therapeutic exercises and injury prevention starting his senior year in high school back in 2015. Soon after graduating from SCSU he received his exercise Physiologist certitication (EP-C) through the top exercise science organization, American College of Sports Medicine (ACSM), specializing in exercise prescription for all populations. Ricky also received his basic life support CPR/AED Certification through the American Red Cross“I am ecstatic to be a part of the team of coaches here at Mason St. Strength & Fitness. The facility is extraordinary. it has evervthing vou need to be vour best and more. Anvone from athletes to the weekend warrior can strive here in a positive environment with coaches that truly want you to succeed."

Jamie Mazzotta | Coach

Strength and Conditioning


Jamie has over 30 years of personal training experience with the Greenwich community. He is certified through NFPT and ACE as well as a licensed massage therapist. His clientele typically includes an older population focusing on stretching, mobility and basic strength work.When he is not working on a client at Mason St you can find him on a paddle board in Montauk.

Zachary Onufrik | Coach

Strength and Conditioning


Zach is a passionate and knowledgeable strength and conditioning coach with both his bachelors and masters degrees in Exercise Science from Sacred Heart University. He is a Certified Strength and Conditioning Specialist.(CSCS) Zach worked in the rehabilitation setting as a Physical Therapy Technician for 3 years with a variety of different patients ranging from athletes to the elderly. During his graduate program he completed two internships with the Sacred Heart University and the Marist College Strength and Conditioning Departments. During this time he honed his skills of programming and coaching various types of division 1 student athletes.

“I decided to work at Mason Street Strength and Fitness because of the professionalism and positive culture that the facility exudes. I am excited to be part of this team of great coaches and look forward to providing high quality training to the community.”