Free-running has recently spread over the digital media and has since become an official sport. Despite this increase in popularity there is no peer-reviewed literature on the physiology and anthropometry of the athletes or the physical demands of the sport. This study aimed to define free-running and explore some of the physiological characteristics of the athletes and the sport, by undertaking the assessment of anthropometric data and vertical jump performance in 7 free-runners; in addition, GPS information was gathered from 3 training sessions for one free-runner. The free-runners in the present study displayed high power output as result of high vertical jump performance. They also displayed low levels of body fat and low body mass. The GPS data illustrated that free-running is an intermittent sport relying heavily on the phosphagenic energy system; therefore, free-runners should focus their training utilising this energy system. Another outcome from the research is the suggestion that future studies should trial different equipment to monitor the physiological demands and intensity of the sport due to particularly high-intensity short bursts of energy utilised. ABSTRACT FROM AUTHOR