Jonathan is a Certified Strength and Conditioning Specialist (CSCS) through the National Strength and Conditioning Association, a Certified Health & Fitness Specialist (HFS) through the American College of Sports Medicine, and a USA Weightlifting Level-1 Club Coach. In addition, Dr. Fass is also a certified ART practitioner, an advanced soft tissue and movement rehabilitation system that treats problems with muscles, tendons, ligaments, fascia and nerves. He is a professional member of the American Physical Therapy Association and Orthopedic and Sports Physical Therapy sections, the National Strength and Conditioning Association, and the American Academy of Orthopedic Manual Physical Therapists.

Jonathan has worked with a broad range of individuals, including athletes, weight loss clients, rehabilitation and post-rehabilitation patients, and elderly populations, as well as general fitness enthusiasts throughout the world. At Rutgers University, Jonathan previously served as the strength and conditioning coach for a wide variety of team sports, including the Women's Club Lacrosse team, the Men's and Women's Rugby Club teams, the Women's Club Soccer team, and Rutger's Water Polo.

Dr. Fass attended his Orthopedic Physical Therapy Residency at the University of Delaware, one of the top-ranked physical therapy programs in the nation. This prestigious appointment consisted of an intense course of specialty orthopedic and sports training including the rehabilitation of varied patient populations, involvement in academic and clinical teaching responsibilities, orthopedic surgical experiences, as well as research.

Dr. Fass has also taught as a lab instructor and part-time lecturer in the Exercise Science department of the Rutgers University School of Arts and Sciences. His writings can be seen in numerous print and online magazines, including Men's Health and Men's Fitness. You can also listen to him every week as a regular co-host of The FitCast, one of the top health and fitness podcasts on the internet.