810-750-0351 PH


Meet Our Trainers

Michael O'HaraMichael O’Hara, P.T., OCS, CSCS

Mike is the owner of Fenton Physical Therapy and Fenton Fitness & Athletic Center.  A graduate of Wayne State University, Mike has over 30 years experience in physical therapy and fitness.  In addition to being a physical therapist, he is also certified through the American Physical Therapy Association as an Orthopedic Specialist.  He is a Certified Strength and Conditioning Specialist through the National Strength and Conditioning Association.

Jeff TirrellJeff Tirrell, B.S., CSCS, CSFS1, Pn1.

Jeff is Program Director at Fenton Fitness and Athletic Center.  A graduate of Western Michigan University, Jeff received his Bachelor’s Degree in Exercise Science.  He is a Certified Strength and Conditioning Specialist through the National Strength and Conditioning Association, a Certified Functional Strength Coach through Mike Boyle Strength and Conditioning, as well as a Level 1 Nutrition Coach through Precision Nutrition.

Jeff brings a wide range of knowledge to all of his training programs through his experience in workplace conditioning at Toyota, collegiate strength and conditioning, powerlifting, and 19 years of personal experience.  Jeff is a competitive powerlifter and has accumulated 9 top 3 finishes, including a 2nd place finish at the 2013 USAPL TX state championship and 1st place at the 2013 and 2015 USAPL MI state championship. He has qualified and competed at USA Powerlifting Raw Nationals two times (2016, 2017).

Jeff strives to continually take courses, attend seminars, and read research to learn new training techniques and make sure that everything he uses is grounded in good research and real world experience.


Sharon Karagozian

Sharon Karagozian

Sharon is a National Academy of Sports Medicine (NASM) Certified Personal Trainer with 17 years of experience here at Fenton Fitness.  Her love of health and fitness prompted her to become a trainer, and she thrives on helping and encouraging individuals to reach their health and fitness goals.  Sharon is personally motivated by strength, wellness, and health and uses this to create her training and nutrition philosophy: Eat well and whole and train for function and health. Sharon stays active and fit through her hobbies of snow skiing, golf, boating, and hiking.



Kristen OwenKristen Owen

Kristen is a Certified Personal Trainer through the American Council on Exercise (A.C.E.).  She cares about people and loves helping them reach their goals. Kristen strongly believes in the vast benefits of exercise in relation to stress reduction, better health, and increased energy, as well as the mental fortitude gained from challenging the body physically. She is naturally active and enjoys hiking, canoeing, horseback riding, and ministry. Kristen’s training philosophy combines food and exercise as medicine: they must be taken in the right dose to get the most benefit.

Katie HoldenKatie Holden

Katie is a Certified Personal Trainer and a specialist in Fitness Nutrition through the ISSA.  Also a gymnastics instructor, Katie has a natural eye for observing and correcting form.  Her fitness journey started in 2011, shortly after high school, when she got her first gym membership.  Since then, she has lost 25 lbs and gained a love for health and fitness.  Always trying to expand her knowledge, Katie attends seminars regularly and is constantly learning.  She stays motivated by seeing her strength improve and participating in powerlifting competitions where she has earned Gold and Silver medals.  She hopes to inspire others to do things they wouldn’t do on their own and help them set and achieve their goals.



Chad Flanagan

Chad Flanagan is a NASM Certified Personal Trainer. For Chad Flanagan, fitness has been a lifelong passion, so becoming a personal trainer was a natural progression in his fitness goals. Married with two young boys, he leads an active lifestyle in and out of the gym. In addition to lifting weights, Chad likes outdoor activities like fishing, hunting, rock climbing, boating, and camping. Chad came to Fenton Fitness with over 20 years of personal experience and looks forward to helping our members attain their own fitness goals. Motivated by others in the gym working hard and friendly competition, his personal goals are to become more flexible and stronger. For optimal results, he pairs his workouts with a simple nutrition philosophy to eat what he wants in a moderate, conscientious way.


Utilizing a trainer on a regular basis will make the time you spend exercising more productive and enjoyable. Your program will produce greater carry over to better function in daily activities, and you will lessen the risk of injury. Most important will be the achievement of fitness goals and the motivation to continue with your program.