Individualization of time-motion analysis : a case-cohort example

Purpose: To report the intensity distribution of Premier League soccer players' external loads during match play, according to recognized physiological thresholds. The authors also present a case in which individualized speed thresholds changed the interpretation of time-motion data. Method: Eight outfield players performed an incremental treadmill test to exhaustion to determine the running speeds associated with their ventilator thresholds. The running speeds were then used to individualize time-motion data collected in 5 competitive fixtures and compared with commonly applied arbitrary speed zones. Results: Of the total distance covered, 26%, 57%, and 17% were performed at low, moderate, and high intensity, respectively. Individualized time-motion data identified a 41% difference in the high-intensity distance covered between 2 players of the same positional role, whereas the player-independent approach yielded negligible (5-7%) differences in total and high-speed distances covered. Conclusions: The authors recommend that individualized speed thresholds be applied to time-motion-analysis data in synergy with the traditional arbitrary approach.