Staff & Expert Contributors

“Creating champion athletes through the application of sport science, expert collaboration, and the ruthless pursuit of excellence.”

Colin Fedoriska

Colin is a Strength & Conditioning coach with a strong background in performance and development of combat sport athletes. The Philadelphia resident is a graduate of temple university and has been working with amateur and professional mixed martial arts fighters in Pennsylvania over the past 5 years. Colin Specializes in weight management and manipulations as well as strength and conditioning programming.


Jesse Rodriguez

Jesse’s focus and emphasis is on Sports Nutrition. He holds a bachelor’s degree in Nutritional Science with the addition of a CSCS certification from the NSCA. Jesse swam for the El Salvador National Team and competed at the international level. Jesse has worked at USC with the Strength and Conditioning program and UCLA as the lead intern for Sports Nutrition. He is currently a dietetic intern to complete requirements for the Registered Dietitian exam and obtain his professional license. During his free time, Jesse continues to strength train, Olympic lift, and stay up-to-date on the latest nutrition trends. Lastly, Jesse is a member of the Academy of Nutrition & Dietetics, National Strength and Conditioning Association, and Collegiate & Professional Sports Dietitians Association.


John Matulevich

John is the owner of Ruthless Performance. Previously, John was a collegiate Strength & Conditioning Coach (NCAA D2) and record-holding powerlifter (4 WR’s/ 9 SR’s – RPS). John specializes in sports performance, exercise physiology, and injury prevention. He is regularly featured in various print and online publications including EliteFTS, Stack Media, and Muscle & Strength. John is the Strength & Conditioning expert contributor to Swimming Science where he works to bridge the gap between the fields of coaching and kinesiology. Through Ruthless Performance, John consults for various businesses, teams, and individuals ranging from adolescent through the professional level. John is also active in health policy, business administration, and throughout his local community.