The paradox of training and injury prevention: should athletes train smarter and harder?
According to common beliefs, injuries are related to
- higher training loads on the one hand, while training has a protective effect against injury on the other. For example, team athletes who trained for more than 18 weeks before suffering their first injury were at lower risk of a subsequent injury, while a high chronic training load has been shown to reduce the risk of injury;
- less well-developed physical qualities associated with a higher risk of injury;
- underdevelopment of physical capabilities as prevention against injury, which require intensive training;
- too little training.
Conclusion: reducing workload is not always the best approach to protect against injury.
An updated injury causation model highlights a number of factors for the occurrence of athletic injuries:
- exposure to external risk factors (equipment, quality sports field, opponents) and potential triggering events;
- fatigue, or negative physiological effects;
- fitness, the possibility of positive physiological adaptations.
Exposure is determined solely by total load, while positive and negative adaptations are controlled by both total load and changes in load (e.g. ratio of incident: regular load).
Using data from 53 top rugby players, Hulin et al (2016) determine the "incidental: regular workload ratio" by dividing the incidental workload by the regular workload. A value greater than 1 represents an occasional workload greater than a regular workload. Players with high incidental workloads and moderately high regular workloads are found to be more injury resistant at ratios between 0.85-1.35 and less injury resistant at 'spikes' in incidental and lower regular workloads, i.e. at ratios ∼1.5.
Gabbett et al. introduce the training-injury prevention paradox: should athletes train smarter and harder to suffer fewer injuries?
Gabbett describes the "Training-Injury Prevention-paradox" model; high training loads lead to fewer injuries than training with lower loads. Because non-contact injuries are not caused by training per se, but rather by an inappropriate training program. Excessive and too rapid increases in training load are probably responsible for a large proportion of soft tissue non-contact injuries. However, physically demanding (and adequate) training develops physical qualities, which in turn protect against injury. This article highlights the importance of monitoring training load, including the load for which athletes are prepared by calculating the ratio of incidental: regular load, as best practice for reducing training-related injuries in the long term.
If training load is an important determinant of injury, it should be measured accurately, up to twice a day and over periods of weeks and months (a season). This article outlines ways to measure training load ('internal' and 'external' load) and suggests recording both recent ('acute') and more medium-term ('chronic') training loads to best assess the player's training load. The critical variable - the ratio of incidental to regular load - is the best practice predictor of training-related injuries. This forms the basis for interventions to reduce player risk, and hence time lost to injury.
Appropriate imposition of high training loads should improve player fitness, which in turn can protect against injury, ultimately leading to greater physical performance and resilience in the game, and a greater proportion of selection available on a weekly basis.