Timothy Clarke is an FDNY Firefighter in Ladder Company 12 in the Chelsea neighborhood of Manhattan and an International Association of Firefighters Peer Certified Fitness instructor (which is a personal trainer for firefighters). He spent three years racing professionally in the sport of triathlon and is a QT2 systems level 3 certified triathlon coach. As both an athlete and a coach, Tim has spent the last 10 years using biometric heart rate data as a tool for training and racing. His experience has given him a unique insight into what happens inside the human body at real world fires and emergencies as well as during workouts and recovery.