Risk stratification and athlete monitoring: optimising training load and minimising the risk of injury and illness
How much is too much has been the burning question for many years. What is the proposed or safest workload that will optimise performance and decrease the risk of injury and illness? It is becoming more over the years the importance of athlete monitoring.[1] Often practitioners and sport coaches are not sure what to monitor or how to interpret the data they have obtained and therefore how to adjust the training programmes or rehabilitation programmes accordingly to minimise the risk of injury or illness.[1] Research thus far suggests that not only should the external workload (i.e. what the athlete does – physical work) and internal workload (i.e. the athletes bodily response to load) of the athlete be monitored but also the perceptual well-being and readiness of the athlete to train and play.[1]
In a study conducted by Jones et al (2017) conflicting evidence was found with regard to how much one should increase the training load by each week to prevent an increased risk of injury.[2]While increased load has been associated with an increased risk of injury, it is suggested that a less than 10% increase in external load per week minimises this risk of injury.[3] Jones found that preseason training may increase the risk of injury either due to a sudden increase in load or as a result of the effects of de-training from off season. Therefore, on the one hand too much loading may lead to fatigue which results in the tissues being able to tolerate stress less as well as having a negative effect on performance and on the other hand, too little loading can also be counterproductive to the tissues and lead to injury due to inadequate stimulus to allow for training adaptations to occur.[2]
Gabbett (2016) has proposed a ‘sweet spot’ in terms of training load– this would be the optimal training load or stimulus that maximises performance while decreasing the risk of injury and illness.[3]He has suggested an acute on chronic workload ratio in which to manage the athletes training. The acute workload recognises the load placed on the athlete over the period of a week while the chronic workload looks at the average loading in the previous three to six weeks of training. If the acute workload is too high and the athlete’s average training load is too low (i.e. their baseline fitness level) then their risk of injury increases. However, if the acute load is high but the athlete’s baseline fitness level is good then the athlete will be more physically ‘fit’ to train and play and less likely to sustain an injury.[3]
While accumulative loading results in greater exposure to training time and match play which may increase the risk of injury (especially when moving from one season to the other), if athletes training programmes are periodized then this will decrease the risk of injury and effect on performance.[2] Training can therefore also serve as a protective factor against injury. Training should be sport specific to allow athletes to adapt to the required workload of competition as more injuries tend to occur in competition than training. If players are able to train safely and effectively through ‘high risk’ periods by adjusting their work load then they may develop better tolerance to loads and therefore better fitness improving their overall performance.[3]
As athletes increase their load, their body will respond accordingly – as discussed this is the internal workload. Monitoring a players heart rate and stress curves can tell us if the athlete is overtraining or undertraining and therefore if their external workload needs to be adjusted. The athletes overall health and well-being (i.e their perception of fatigue and stress) will also affect their training and performance. This too can be used as a measure to adapt the players training load during the high risk period to decrease the risk of injury. A sudden increase in load has shown to lower one’s immune system. This is known as the latency effect of illness and training load.[2]If the markers of illness/immune function do not return to normal within three weeks, this increases the risk of an athlete sustaining an upper respiratory tract infection. Therefore constant monitoring of the athlete is highly important.
It is recommended that baseline stress curves and heart rates of athletes should be established during pre-season and in season training to determine if athletes are heading into the ‘danger zone’ of sustaining a potential injury or illness and therefore if adaptations need to be made to the training load. A gradual increase in the training load of less than 10% per week should be adhered to. It is recommended that athletes training programmes should be periodized (i.e. a gradual increase in load for three weeks followed by a decrease in load for a week). This allows the body to recover and adapt to the training stimulus. Lastly, the athlete’s rate of perceived exertion should be monitored on a weekly basis as a tool to determine the athlete’s overall well-being with regard to fatigue and stress. This should then also be used to guide appropriate adaptations to the respective training or rehabilitation programmes.
References
1.Gabbet TJ. The athlete monitoring cycle: a practical guide to interpreting and applying training monitoring data. Br J Sports Med. 2017;51:1451-1452. doi: 10.1136/bjsports-2-16-097298.
2. Jones CM, Griffiths PC, Mellalieu SD. Training load and fatigue marker associations with injury and illness: A systematic review of longitudinal studies. Sports Med. 2017;43:943-974. doi: 10.1007/540279-016-0619-5.
3. Gabbett TJ. The training-injury prevention paradox: should athletes be training smarter and harder? Br J Sports Med. 2016;50:273-280. Doi:10.1136/bjsports-2015-095788.
*Nicole is an enthusiastic, vibrant physiotherapist working in private practice in Cape Town. She is currently completing here second year of MSc. at the University of Cape Town in Sports and Exercise Physiotherapy. Her dissertation explores training loads, injury and illness profiles of Ultra marathon runners. She enjoys running, cycling and the exploring the outdoors.
