The Story

Cardio Sport was created by Founder, John Duffy in 2006.  As a long time high level athlete, John found himself bored and unmotivated by the fitness options available to keep himself moving after his playing days were over. 

In an effort, at the time, to improve his own fitness he began to work out in the group exercise room in the 30,000 square foot fitness facility he owned at the time during off hours. Before long, people were wondering what he was doing. It looked fun, and they noticed him getting in great shape. One by one people began to join him and before long he had such a large group that he formalized his program into a class, which he called Cardio Sport, and put it onto his group exercise schedule. At the time is was offered on a very limited basis and the he used his diverse knowledge of sports, music and athletic training to create a fun, and highly motivational environment for athletes that got them great results.

In 2008, after 2 years of running his classes and growing the group to 100+ people, he decided to formalize his program and dedicate his life to developing the Cardio Sport Exercise System. Now, over a decade later, Cardio Sport is one of the most effective and comprehensive exercise systems in the market.

The program is designed for athletic minded people. Who is an athletic minded person? It can be anyone – a former athlete, a current athlete or a fan that loves sports but never had a chance to play. Athletic minded people think differently and are motivated to move by different things than people who love traditional fitness offerings.  They like to train in environments that provide a purpose greater than just exercise, require constant decision making, mental engagement and have a feel of team. 

The System

The Cardio Sport Music & Movement Studios concept is simple.  It is a brand, studio and program that is built around catering to, and engaging the minds of athletes of all ages.  Cardio Sport has figured out what motivates the mind of an athlete and created an exercise experience and system that gets the elite fitness results that athletes are seeking, while motivating them to come regularly through a unique ‘in the game simulations strategy’ and branded environment that makes them feel like they did when they played the game.

The Cardio Sport Exercise System (“The System”), which is offered in Cardio Sport Music & Movement Studios is a proprietary exercise system that Cardio Sport, LLC has developed.  Their strategy circles around a unique ‘in the game’ simulation training environment designed to train athletic minded participants of all ages – both their bodies and their minds.  Through the continued participation in this training method Cardio Sport Participants are able to achieve their individual optimal performance potential.

The Cardio Sport Exercise System is comprised of two components, the GROUP DYNAMIC Large Group Training Sessions and the CST personal / small group training sessions.  Combines, this comprehensive training program provides a motivation, that drives extraordinary consistency amongst followers, allowing both athletic performance and general wellness clients to achieve optimal results.

The Cardio Sport Exercise System Experience is delivered in a one of a kind, athlete-meets-rockstar branded training studio that is designed to provide the optimal brand experience, training experience, motivation and results for each client.

The Team


John A. Duffy Jr.


“The Short” of It…

John is the mastermind behind the Cardio Sport™ Exercise System.  John’s deep knowledge of how the human body functions, coupled with his supreme mastery of how to apply his knowledge to get elite results, has been the foundation from which the Cardio Sport Exercise System was developed.

Over the past decade, through Cardio Sport, John has personally trained  thousands of people (athletes and regular people) with extraordinary results.  Over the past 2 years, he has also taught hundreds of instructors, trainers, athletes, PE teachers and coaches to use his methodologies through Cardio Sport’s national certification initiative.  Using his system and philosophies, Certified Cardio Sport Instructors around the nation have achieved outstanding results within their own participations.

John’s exceptional skill and mastery of his expertise is demonstrated year after year through the thousands of people who have changed their bodies and lives as a result of Cardio Sport.

And “The Long” of It…

Growing up John was a skilled athlete, playing numerous sports, including soccer,  hockey, basketball, lacrosse, baseball and tennis at the high school, collegiate and post collegiate level.  Always the team captain, he was a passionate athlete that dedicated thousands of hours to training and practicing for his sports. As he became older, it became very apparent that although John has natural skill, he had a unique ability to understand how to train his body to maximize his results and performance in the game.

In addition to a love of sports and physical movement, John is also intensely passionate about music and the psychology of people. Both of these life long fascinations play a key role in his development of Cardio Sport, and ultimately the program’s phenomenal success. For a  fitness program to be truly successful over a long period of time, it must produce far more than just physical results. John’s clear understanding of this concept early on, coupled with his keen ability to create an environment that inspires and motivates people to achieve more than they could ever imagine possible, has been life changing for many and created Cardio Sport’s success.  Cardio Sport participants around the country will tell you that they are impressed by the fitness results they receive, but even more impressed by how their participation in the classes has impacted them mentally and emotionally. 

John graduated from Adelphi University with a BS in Finance and began his entrepreneurial endeavors by the age of 25. He has owned and operated three companies and today chooses to focus his energy,  passion, extensive experience and knowledge into the Cardio Sport national initiative.

Hilary heads up sales, marketing and brand development. She became involved with Cardio Sport over 3 years ago as a participant. She is a long time entrepreneur, with over a decade of experience in business and product launch strategy.

Having been raised in an entrepreneurial environment as a child, Hilary knew from a very young age that she would some day work for herself – she just wasn’t sure when or what it would be. After college, she launched her career in the corporate world and spent several years working to gain the knowledge to break out on her own. By 29, she began as strategic consulting firm that focused on medical device clients.  Six years later she had built a very busy and successful firm, which regularly employed 7-10 other consultants and served over 30 different companies, including all of the major players in the medical device industry and a number of up and coming start ups.

In the Fall of 2013, she was a point in her life where she wanted more than just financial success. She wanted to apply her knowledge and skills to something she was truly passionate about. After a class one day, she had a casual discussion with John regarding Cardio Sport’s national business strategy. She was intrigued and offered to help co-write the business plan for this new arm of John’s business. She always knew that Cardio Sport was something special – not just another fitness program, but after diving into the project, she began to recognize  the significant business opportunity that Cardio Sport presented.

After working on a few projects here and there, and maintaining her firm, she hit the proverbial fork in the road that every entrepreneur eventually meets. Go forth in full or step back…So she made her decision and in 2014,  she  jumped in head first to follow her passion. She exited her consulting firm and began her journey to focus full time on building Cardio Sport’s National Certification Program. Things have been fast and furious ever since, but she has never looked back.  Every day she is thankful to have the opportunity to devout her passion, enthusiasm, experience and knowledge to something she truly loves.

In January 2015, Hilary became a Partner in Cardio Sport.  Hilary holds a BA in Communications from the University of Massachusetts  at Amherst and an Executive Management Certificate from Northeastern University.


Hilary Hartman

VP Marketing & Business Development


Katie O’Connell

National Corporate Instructor / Weymouth Studio Lead

Katie is a long time athlete, who played soccer competitively throughout her high school and college years.   When she stopped playing on a team, she found herself uninspired by other fitness options out there. Like many athletes, Katie’s first Cardio Sport class changed her life. She connected to the challenge-based, play filled, team sport feel because it gave her a purpose and passion for physical movement again. It was this connection that lead her to pursue a deeper understanding of Cardio Sport’s method, and ultimately to where she is today. Katie runs the Cardio Sport Weymouth Studio and is an integral part of our National Corporate Instructor team. Katie graduated from Clark University.

Mara played both soccer and hockey in her high school years. It was her passion for movement that lead her to become a Cardio Sport Instructor almost three years ago. Mara is an Inside Support Trainer who instructs in the Corporate studios, and works directly with our national client-base  to provide post-certification support for successful implementation of  the Cardio Sport Training methodology. Mara loves working with our clients to share her passion for Cardio Sport, both in teaching classes and helping other instructors learn to lead classes around the country. Mara is a long time Duxbury resident and holds a business degree from Lasell College.


Mara Murphy-Kusins

National Corporate Instructor / Inside Support Trainer

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