With the development of wearable GPS and inertial movement devices, quantifying training load in sports teams has become much more convenient and are becoming more affordable to smaller-budget programs. These devices quantify movement in all directions and speeds, providing the coach with useful metrics to determine how much distance is being covered and at what speeds during training and competition. Several studies have been published aiming to evaluate injury risk based on training load. In short, it appears that injury risk may be heightened when loads are too high or too low. Building work capacity up high with heavy loads appears to be protective against injury up to a point, at which higher loads increase risk. Low training loads may not prepare athletes enough for the rigors of competition and thus may also increase injury risk.
A recent study published in the Journal of Strength and Conditioning Research aimed to evaluate injury risk in D-1 collegiate football players throughout a competitive season. This is the first study of its kind to evaluate American football players as the majority of research in the area has been with soccer and rugby teams. A total of 45 players from an elite program wore inertial movement devices during practices and games throughout a full season. Inertial movement was quantified using “PlayerLoadTM” for each session and musculoskeletal sprains and strains were recorded. The authors aimed to determine if training load was at all associated with the occurrence of injuries.
The results showed two important trends that significantly related to injury risk. First, and not surprisingly, greater exposure to competition loads significantly increased the players risk of injury. Essentially, if you’re not getting much playing time during games, you’re less likely to get hurt. The second trend was that players with less fluctuation in training load on a day-to-day basis (assessed via the coefficient of variation in PlayerLoadTM) also appeared to be at an increased risk of injury (Odds Ration = 8.04). In other words, players were more likely to get hurt when they were exposed to similar loads day in and day out. Therefore, ensuring that loads vary sufficiently throughout the week may be useful to reduce injury risk in football players.
Wilkerson, G. B., Gupta, A., Allen, J. R., Keith, C. M., & Colston, M. A. (2016). Utilization of Practice Session Average Inertial Load to Quantify College Football Injury Risk. Journal of strength and conditioning research/National Strength & Conditioning Association.