by Ebru Efe
“When can I play again?”
This is often one of the first questions asked by an injured athlete, yet one of the hardest to answer. A number of factors and decisions come into the injury pathway taken by the athlete, alongside their coach, physiotherapist and other health professionals.
Load and the injured player:
Load is a key factor in the question above. ‘Load’ describes the overall work or effort the player experiences, considering both sport and non-sport stressors affecting the player and their body. Load can be categorised into:
External load: physical work, such as total distance or minutes of running
Internal load: the physiological and psychological responses to work, measured by heart rate or by perceived exertion (how hard you feel you have worked, scaled from 0 to 10). This can be affected by life stressors, the presence of fatigue or environmental changes 6.
Managing an athlete’s load becomes critical in minimising their injury risk, as well as guiding rehabilitation and return to sport following injury. A response to the question above should be guided by the athlete’s previous, current and upcoming load.
How much load? The acute:chronic workload ratio:
The acute:chronic workload ratio outlines the training load of that current week (acute) over the average weekly load of the previous 4 weeks (chronic). A high chronic workload, built over time, reflects a high level of fitness. In contrast, a rapid spike in acute workload, compared against their chronic workload, produces a high risk of injury 5. This is a common scene in athletes rushing back from injury, making a safe return to soccer challenging on the player and their body.
How do I measure load?
Considering both external and internal load allows for appropriate management, to identify health or performance deficits and make suitable adjustments to training and competition. A common approach to measuring a session’s load involves calculating:
External load (i.e. minutes) x internal load (i.e. rate of perceived exertion from 0-10). This provides a scientific and practical approach to measuring individual player load within a team environment, without the need for technology or equipment 3.
For the recreational or younger athlete, number of hours per week can provide a convenient measure of training volume. For example, a young player may complete three 2-hour training sessions, one school match and one club match, accumulating 9 hours in a usual week (chronic load). If they have been injured and only completing 3 hours of jogging or rehabilitation per week, returning to 9 hours would represent a rapid spike (acute load) and leave them susceptible to injury. A gradual build in workload over time, both in duration and intensity, would avoid this risk.
Managing (and building) load – the “Goldilocks” approach:
The appropriate progression of load is a key to success for the injured athlete. The “Goldilocks” approach, viewing training progression as ‘not too little, not too much’, is a popular way of thinking about this return from injury 1,4. Training workloads should aim to improve fitness, without being so high as to risk injury. This balance between performance and harm can be challenging to find. A weekly increase of <10% is advised, to build training load while minimising the risk of injury 3.
Return to sport:
The athlete and physiotherapist share the decision and goal to safely return the injured player to training and match play. In line with our understanding of load management, this should follow a graded progression with three broad phases:
Return to participation: modified or unmodified training, in addition to rehabilitation, but at a lower level than the athlete’s goal.
Example: involved in team warm up and passing drills, no match play
Return to sport: the athlete has returned to their sport, but may not be at their desired performance level.
Example: full training with reduced or limited match time (e.g. 60 minutes)
Return to performance: a gradual return to competing at a level at or above their pre-injury level, where the athlete feels they are giving their ‘best’ performance
Example: full training and matches, unaffected by resolved injury
A successful transition through these phases relies on structured and defined goals, well understood by the athlete and supported by experienced decision-making by the physiotherapist 1.
Maintenance:
The maintenance of high training loads over a chronic period appears protective against injury 3. To avoid rapid spikes and future injuries, players should gradually increase their chronic workloads, building physical fitness and improving performance in the process. A gradual progression towards this high chronic load makes for a resilient, injury-free player.
References:
1. Ardern, C.L., Glasgow, P., Schneiders, A., Witvrouw, E., Clarsen, B., … & Bizzini, M. (2016). 2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern. British Journal of Sports Medicine, 50, 853-864.
2. Blanch, P., & Gabbett, T. (2015). Has the athlete trained enough to return to play safely? The acute:chronic workload ratio permits clinicians to quantify a player’s risk of subsequent injury. British Journal of Sports Medicine, 50, 471-475.
3. Gabbett, T.J. (2016). The training-injury prevention paradox: should athletes be training smarter and harder? British Journal of Sports Medicine, 50(5), 273-280.
4. Gabbett, T.J., Hulin, B.T., Blanch, P., & Whiteley, R. (2016). High training workloads alone do not cause sports injuries: how you get there is the real issue. British Journal of Sports Medicine, 50(8), 444-445.
5. Hulin, B.T., Gabbett, T.J., Lawson, D.W., Caputi, P., & Sampson, J.A. (2015). The acute:chronic workload ratio predicts injury: high chronic workload may decrease injury risk in elite rugby league players. British Journal of Sports Medicine, 50(4), 231-236.
6. Soligard, T., Schwellnus, M., Alonso, J., Bahr, R., Clarsen, B., … & Engebretsen, L. (2016). How much is too much? (Part 1) International Olympic Committee consensus statement on load in sport and risk of injury. British Journal of Sports Medicine, 50(17), 1030-1041.
