865-657-6190 | Flexx Fitness PT | 266 Mialaquo Center | Loudon, TN 37774

About the Staff

Brent Parkhill, MBA, ACE
Owner & Founder of Flexx Fitness Personal Training Solutions

Brent Parkhill imageFirst, you should know that I am as competitive as they come. When I was younger, all I wanted to do was to earn a scholarship to play football at a Division 1 college. On occasion, I was told that I was not big enough to play (truth be told…I was pretty skinny growing up). Most kids would have quickly given up on their dream, but not me – I’m as stubborn as they come. I started lifting weights at 12-years old to get stronger. I took some notes from the elite bodybuilders of the time and noticed that I was getting stronger and faster. By the end of my senior year in High School, I was 6’4” and had built my frame into a 225-pound monster and, oh by the way, I was an outstanding linebacker. I received over a dozen scholarship offers from Division 1 football programs around the country! Not bad for a skinny kid from upstate NY.

I decided to accept a full athletic scholarship at the University of Toledo where I started for three years. During my final season, our football team earned a top twenty-five ranking and started a storied winning tradition for the Rockets. In 1995, I graduated with a bachelor’s in business administration and went on to complete my MBA in 1997 (graduating with high honors).

I started my corporate life in 1997 and in 2003 I walked away from a very successful sales career to enter the fitness industry. My first love had always been in the gym growing, learning, and suffering (with growth and continued knowledge there is always suffering). The same year I was certified as a strength and conditioning coach/personal trainer by The American Council on Exercise (ACE) and started my training career at a nationally recognized health club where I won multiple awards and received many accolades. In 2006, I opened my first training business in the suburbs of Chicago where I trained youth athletes and corporate executives. In addition, I initiated a corporate wellness program at the headquarters of a national office supply company as well as several other mid-size businesses in the area. In 2015, my family and I moved to Knoxville, Tennessee to escape the cold weather and enjoy all living in East Tennessee provides. I’ve been a personal trainer in the Tellico Village community since the first day we arrived here and I love it. My challenge to you is to commit to be the best version of yourself. In your pursuit of health, wealth, or any other marker, remember this quote:

“Success is a journey, not a destination. The doing is often more important than the outcome.”

–Arthur Ashe


Mark Croy, MBA, MHCA, L/ATC, CSCS, TGFP 2, SFMA, FMS 2, CFSC,FMT, Medical Fitness/Sports Performance
Flexx Fitness Personal Trainer

Mark received his undergraduate degree in Athletic Training from St Ambrose University in Davenport, Iowa.  He also received both of his post graduate degrees from St Ambrose as well. He has Master degrees in Health Care and Business Administration.

Mark is a Tennessee Licensed, Nationally Certified Athletic Trainer, Nationally Certified Strength and Conditioning Specialist through the National Strength & Conditioning Association (NSCA), Certified Titleist Golf Fitness Professional (Level 2), Certified Specific Functional Movement Assessment Specialist, Certified Functional Movement Systems (Level 2) and Certified Functional Strength Coach and Functional Movement Tape Certified (Kenesio/Rock Taping).  

Mark and his family just relocated to Tennessee from Ft. Lauderdale, FL and joined the Flexx Fitness family in 2019.  He has lived, worked and trained all over the world.  Mark played football for the Air Force and Semi-Pro football in California.  He has been helping people change their lives as a Health/Sports Performance Professional for over 23 years.  He specializes in sports medicine, pain management, sports performance coaching and is a movement practitioner.

Many of Mark’s clients/athletes have physical limitations caused by pain, or injury.  One of Mark’s specialties is working with chronic and/or acute pain.   His knowledge and expertise in physical movement screening has allowed him to have great success with clients in reducing or completely eliminating their pain and restoring their function.

Mark believes that exercise and physical therapy should be approached as a process not a task.   Mark thinks out of the box, meshing different proven therapies, using cutting edge exercise/therapeutic techniques and designing specific programs for individuals to achieve success.  Mark uses many tools to help his clients on their journey to better health.

Mark also has extensive experience working with individuals and teams to improve sports performance.   He has trained athletes from many sports…equestrians/trick riders, bowlers, cyclists, tri-athletes, marathoners, sprinters, baseball pitchers and many others.  Mark’s greatest accomplishments have been training a National Champion Volleyball Team and working with Tour level golfers.

Mark has been married to his wife for over 20 years, who happens to be the Chiropractor inside Flexx Fitness.   They have 3 children, two sons and daughter.  In his spare time, Mark enjoys golfing with his friends/family, traveling and most of all watching and coaching football.

Mark’s favorite saying… “I just don’t change bodies, I change lives”


Dr. Sharon Sassen-Croy, DC, BS
Chiropractic Physician

“Dr. Sharon” earned her Bachelor of Science degree in Exercise Science along with double minors in Health Studies and Psychology from Iowa State University. She earned an additional Bachelor of Science degree in Human Biology, as well as her Doctor of Chiropractic from National University of Health Science outside of Chicago. She is also a Certified Weight Loss Coach and is Rock Tape Certified (kinesio-taping).

Dr. Sharon Sassen has over 20 years’ experience in the Health/Fitness and Chiropractic industries. She enjoys working with a variety of patients – young to old, athletes and non-athletes alike. Over her years in practice, Dr Sharon has treated and managed numerous conditions and injuries utilizing an assortment of “tools.” Using her “tools” she offers a variety of services in her practice: Chiropractic Care, Nutritional Guidance, Custom Orthotics, Physiotherapy, Corrective Exercises, Myofascial Work, Kinesio-taping. Having medical professionals in her family, and a broad background in health, Dr. Sharon can also assist with referrals to other health care professionals if needed. Dr. Sharon enjoys challenging cases, research and finding solutions for her patient’s health concerns.

In her free time, along with her husband Mark Croy (also of Flexx Fitness), Dr. Sharon keeps herself busy with their three kids, 4 pets, travel and the great outdoors.  Dr. Sharon works with people who train at Flexx Fitness as well as anyone from the general public, come on in and see if she can help you!