Training to achieve high performance and minimise the risk of injury.
A training and rehabilitation program must ensure that it develops resilience through exposing the athlete to physically intense training to prepare them for the demands of their chosen sport. It also must be ensured that the athlete is not exposed to ‘load-related’ injuries.
As physio’s we are interested in the relationship between training load, injury, and performance, as a ‘training load injury’ could be argued, is preventable. Managing load considers appropriate prescription and monitoring and adjustment of external and internal loads.
What is a load related injury?
A musculoskeletal injury that may be caused by applying too much stress to the body, usually as a result of lack of recovery time and an increased intensity of training. It is common in the lead up to big events, and after injuries. Beginners are also more susceptible as they may think they can produce quick results if they train hard.
If a tissue is exposed to excessive load beyond its load bearing capacity, or insufficient recovery, it may leave to microdamage and injury. e.g. Overuse injuries such as stress fractures and tendinopathy.
Inappropriate loading can also have a negative impact on the whole athlete. Fatigue from training may cause poor decision-making skills and coordination, and poor neuromuscular control. This can lead to reduced muscular force on tissues and alter technique and contribute to the risk of injury.
So how to train optimally?
Measure training loads and use the data to find the sweet spot!
Measuring training loads:
EXTERNAL LOAD – The physical work. Examples include hours of training, distance run, watts produced, number of games played or balls bowled. GPS is a typical tool used to measure external load in athletes.
INTERNAL LOAD – The internal response to the external load. Examples include heart rate or rating of perceived effort (RPE). Athletes may state the RPE (1-10) on the intensity of the session. The is multiplied by the duration. For Example: 3(RPE) x 120(minutes) = 350.
Find the sweet spot!
The acute:chronic workload ratio (ACWR) is used to describe the acute training load (e.g. the past week) to the chronic load (e.g. the average of the past 4 weeks). i.e. What the athlete is doing now compared to the preparation the athlete has already done.
Research has found that if the ACWR is kept in the range of 0.8-1.3, injury risk is reduced, and training benefits are maintained.
Using running as an example: 20km (this week) / 18km (average of the past 4 weeks) = 1.1
Using balls bowled: 45 (this week) / 25 (average of the past 4 weeks) = 1.8. This means that the load this week is 1.8 times greater than the average of the previous 4 weeks and this in the ‘danger zone’.
Using RPE while training for Rugby: 350 (this week) / 2000 (average of past 4 weeks) = 0.2. This may suggest that there is insufficient training to achieve adaptive changes.
Provided the athlete reaches loads in a gradual and controlled fashion, optimal training adaptations should be made and the risk of a load-related injury minimised. Monitoring should be done frequently to enable adjustments to be made to the training program.
Bear in mind that this is not a guaranteed method to stop all injuries, however it is a researched and user-friendly method to use – especially for beginners or those returning from injury.