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Core Dynamics Staff

Jim O’Hagan

Owner/Head Fitness Coach


After struggling to find a facility that met his expectations Jim opened Core Dynamics in January 2006. “The fitness industry is constantly being devalued due to poor management and a lack of serious professionals, which lowers a members expectations of their fitness experience. People are led to believe that what makes a great fitness club is the size of the facility and how much equipment you can fit into it.  I believe there are many factors that go into a great club… but it all starts with a great staff”. With a degree in exercise science, countless certifications and almost 25 years of experience, Jims’ passion for knowledge, along with his desire to assist people in reaching their fitness goals continues.  “Strength for Life is more than a company slogan for me…it’s a philosophy that guides me every day."

Ann Meras

Manager/Program Director


Manager/Group Fitness Instructor
Ann owned and operated Manhattan Body, Inc., an exercise studio on New York City’s Upper East Side between 1983 and 1996. She is author of the book Thighs to Die For and inventor of the Focus Weight. She served as the Fitness Coordinator for the Norwich Inn & Spa and was the exercise Consultant for a series of Time-Life Books on Fitness, Health & Nutrition. Ann has worked as a fitness instructor for Core Dynamics Gym since 2008. She became manager in October of 2016.

Joao Monteiro

Fitness Coach

Joao is a passionate professional who exudes positive energy. He is a Certified Physical Preparation Specialist (CPPS). His curriculum covers many aspects of strength and performance training; including pre-training preparation, breathing, mastering fundamental movement patterns, strength and power training and speed development. Joao is a former triathlete/long distance runner. He’s competed in many long distances races, including 5 Ironman Triathlons.

Antonia Mennis

Licensed Massage Therapist


After receiving her B.A. in Humanities at Dowling College, Antonia wanted to further her education and pursue a career that would help impact people’s lives. Antonia graduated from the New York College of Health Professions in 2007 with a degree in Massage Therapy. After her first year working at a prestigious health spa in the Hamptons, she decided to join Core Dynamics. With her passion for health and fitness as well as massage therapy joining the Core Dynamics Family seemed to be the perfect combination for her. Antonia specializes in Sports and Deep tissue massage, a favorite amongst her clients. “Massage therapy has the ability to change a person’s life. It renews, restores and provides a form of preventive care that should not be overlooked. I truly feel that I make a difference in my clients’ lives. If I can simply help someone feel better, that’s all that matters.”

Didi Frizell

Fitness Coach


Didi has been in the business of “fitness” for over 25 years. She is a Certified Fitness Strength Coach (CFSC) and Functional Movement Specialist (FMS). Didi enjoys working with people of all ages to help them adopt a healthy lifestyle and achieve greater fitness levels. “I get great satisfaction in helping my clients reach their personal health and fitness goals through a tailored, progressive program that creates balance and harmony in their daily lives".

Robin Bush

Group Fitness Instructor/Fitness Coach


Intensity, challenge and pushing others towards their goals have been Robin’s focus over the course of her 30+year career in the fitness industry. Robin calls Core Dynamic’s her home.  There’s such great camaraderie between the members and the staff of Core.  It’s a boutique studio style gym and the members’ needs are always the primary focus. Robin enjoys working with individuals and creating personalized fitness programs. She puts an emphasis on strength training in her programming. “As we age, the need to build muscle and strength becomes more and more imperative. Women especially, should never be afraid to build muscle, as it is the fountain of youth”.  Robins’ favorite class to teach is “Core, Cycle and Strength”. The intensity of cardio intervals on the bike is a perfect complement to the strength training that is done off the bike.

John Erickson

Fitness Coach/Nutritionist


John is a nutritionist and fitness trainer. He is the creator of the Core Fat Loss plan, author of 15 diet books, and has 20 years of experience in the field of nutrition. After becoming certified as a 40/30/30 Nutritionist and Zone Diet instructor, John ran the kitchen operations for a Long Island hospital and for the popular Zone Diet delivery service where he learned the importance of balancing macronutrients (carbohydrates, proteins and fats) to ensure stable blood sugar levels, maximize performance, and to promote fat loss. John holds multiple personal training certifications through NASM, NFPT, TRX, and FMS. John joined Core Dynamics in 2008 and continues to promote self-sufficiency by providing his clients with the tools necessary to control their own health through nutrition and fitness.

Elizabeth Falkowski

Owner and Instructor of Water Mill Pilates


Elizabeth began her study of Pilates through her classical ballet training and discovered its amazing benefits for injury prevention and rehabilitation. Elizabeth holds a BA in Dance Movement and Health Promotion from Mercy Hurst University. Her studies in anatomy/physiology, nutrition, sports and health psychology, as well as body mechanics, have allowed her to meet the individual needs of her clients and bring a holistic approach to fitness. Elizabeth received her classical Pilates certification through Power Pilates NYC Elizabeth opened Water Mill Pilates, located in Core Dynamics Gym, in 2007. Elizabeth’s dedication to a healthy, balanced life, along with her understanding of movement in the body, drives her passion for teaching.

Karolina Vuik

Licensed Massage Therapist 


Karolina graduated from NY College of Health Professions in Syosset in 1999.  When she first began massage school it was more about having a job with a flexible schedule so she could travel and spend time with her family. Since then it has become so much more; “I love what I do! To be able to help people emotionally and physically is very rewarding”. Karolina specializes in swedish, deep tissue, amma therapy (pressure point massage) Infant massage and hot stone massage.

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Rene Lund

Fitness/Boot Camp Instructor


Rene’s lifelong commitment to fitness and teaching is focused on continually moving forward and striving to do one’s best in whatever path is chosen. Her fitness paths have taken her to pools and roads, trails and mountains, gymnasiums and studios, pushing herself and others to set goals and move toward them with intent and intensity. AFFA and ACE as well as the specificity of such programs as Keiser, Schwinn, Maddog, Cycleops, BOSU, YogaFit, BodyPump and TRX have provided the learning platform. From her first minutes at Core Dynamics, she knew she found a fit. Rene’s path at Core has brought her and her passions to teach Outdoor Bootcamp, Cycling, and TRX classes. The journey continues...

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