Monitoring fatigue involves various methods of examining the psychological and physiological fatigue accumulated from athletic competition. This is a very important tool for performance practitioners since high levels of fatigue can inhibit proper adaptation to training and hinder performance in competition. Monitoring fatigue levels in athletes can provide important feedback needed to adjust training in order to improve overall performance.
There are various ways to monitor fatigue through different subjective and objective measures. While many practitioners have developed comprehensive fatigue monitoring programs, there is still high demand for more research to verify the best methods for understanding fatigue.
What is Fatigue?
Muscle physiologists have previously described fatigue as a decline in muscular force due to exercise. However, exercise science research has broadened a likely definition as, an exercise-induced diminishment or impairment of performance.
While both sides agree that fatigue is related to objective measures (i.e. performance and physiology), they fail to include subjective measures (i.e. perceived stress, mood, etc.). It has been suggested that appropriate fatigue monitoring should include both objective and subjective measures. Because of this, perhaps the best current working definition of fatigue is ‘any exercise- or non-exercise-induced loss in total performance due to various physiological factors, athlete reported psychological factors, or a combination of the two’.
Whilst there are many mechanisms of fatigue described in the literature, and numerous theories, here we will focus on two distinct forms:
- Central fatigue
- Peripheral fatigue.
Central fatigue is described as fatigue coming not from the muscle itself, but rather from the central nervous system (CNS) and the transmission of signals from the brain to the muscle. Therefore, central fatigue is related to the brain and the spinal cord. The human body is a complex system that wants to continually remain in homeostasis. Upon performing physical work, such as training, the CNS will provide neurotransmissions which, in turn, regulate the amount of work being completed. This is done in a regulatory attempt to prevent bodily harm from occurring. The signals coming from the CNS will experience fatigue which can differ on an individual basis. It has been suggested that a difference between good and great athletes could be their individual ability to ignore these neurotransmissions in an effort to complete the task at hand.
On the other hand, peripheral fatigue may be defined as the failure to maintain an expected power output and can be caused by two different actions. The first being the depletion of resources within the muscular unit. Secondly, peripheral fatigue can be caused by the accumulation of metabolites that are released during activity. Therefore, peripheral fatigue occurs within the muscle unit.
Why is Monitoring Fatigue Important?
As training under high levels of fatigue can result in little to no training adaptation, monitoring the amount of fatigue is therefore important for any practitioner that is attempting to optimise an athlete’s performance. As such, monitoring the athlete’s freshness will provide the coach with some level of knowledge regarding the athlete’s sensitivity to adaptation and/or their ability to perform.
An athlete’s training program (i.e. dose) and the corresponding levels of fatigue associated with that program (i.e. response) is often referred to as the dose-response relationship. Therefore, a coach must fully understand the dose-response relationship of their athletes’ training programs if they are to maximise performance, especially on the day of competition. Given this, the process of monitoring fatigue is an attempt to improve the so-called art of periodisation for competition with an ‘evidence-based decision making system’.
In other words, the importance and advantage of implementing a fatigue monitoring system is having the ability to see how each athlete is responding to training. If the goal is to maximise or maintain performance, then having the knowledge as to how the athlete’s body is responding is critical. Knowing when an athlete is responding well to training, versus when the athlete is not, is essential from a training prescription standpoint. Having this information will allow the coach to adjust an athlete’s training programme as necessary to ensure continual adaptation, prevent overtraining, and ultimately maximise performance.
At its core, fatigue monitoring is simply a method of assessing an athlete’s readiness to train or compete. It is easy to see how this could be extremely important for the coach looking to take their athlete to the next level, however, fatigue monitoring is not a simple subject. There are numerous subjective and objective practices that can be used to monitor each athlete, some of which are much simpler than others, and some methods are better supported by research.
Before implementing a fatigue monitoring system, the practitioner should determine which methods are supported by research, which ones they have the capabilities of using, and also which one is best suited to the athletes they are working with. Having a consistent and accurate set of data to work with will give the best results and, in turn, have the best positive effect on the training of each athlete.
Bringing Subjective Information into Athlete Monitoring Processes
The majority of effective training programmes combine objective performance measurement with subjective wellness monitoring to build a multi-dimensional picture of athlete condition.
When we talk about subjective wellness monitoring in the context of elite performance, we are generally referring to the monitoring of factors like diet, sleep, muscle soreness, stress, mood, perceived exertion during training sessions, and potentially even broader psychosocial indicators. If combined with data-driven load management processes, this type of work can provide valuable additional insights into how individual athletes are coping with the stimulus imposed on them through both training and matches.
One of the most widely used subjective measures in the context of sports is the Rating of Perceived Exertion (RPE) scale. This scale is a quantitative measure of intensity of a session. RPE gives athletes the ability to choose a number on a scale ranging from ‘no exertion at all’ to ‘maximal exertion’.
Despite not being an objective measure of load or fatigue, RPE is a simple way to improve communication between coaches and athletes. RPE is also important for understanding exactly how your athletes feel within themselves and assess whether the external stresses players are exposed to are having the expected impact in terms of internal load.
When it comes to wellness factors closely associated with performance, high quality sleep is widely acknowledged to be an essential part of an athlete’s ability to adequately recover and play at their optimal level. According to a 2011 study conducted by researchers at Stanford University, college basketball players who slept for a minimum of ten hours per night for a 5-7 week period demonstrated improved sprint times, shooting accuracy, free throw and field goal percentage.
In recent years, many elite football clubs have started to take the science of sleep more seriously. For example, Swansea City installed sleep pods at their training ground in 2015 to help players recover between strenuous pre-season sessions. Similarly, AFC Bournemouth started giving their players ‘sleep packs’ during the 2017/18 season. Including eye masks and tinted glasses, the sleep packs are designed to give the athletes a better chance of getting quality sleep when they are away from their home environment.
Of course, the collection and application of this sort of information can only be done effectively if it is easily captured, carefully managed, and made available to the relevant staff. Athlete management systems can help with this by giving organisations the ability to store all performance, medical and wellness information in a central location.
By improving the management of data in that way, it becomes easier to derive and communicate key insights based on both objective and subjective information that can have a material impact on performance and coaching practices.
The Four Pillars of Performance
A practitioner’s ability to optimise an athlete’s capacity for performance is typically divided into four key pillars that are all pieces of the puzzle that governs success in competition:
- Technical - the foundation of a player’s ability
- Tactical - decision making and game strategies
- Physical - attributes and capabilities to compete against others
- Psychological - development, confidence, resilience and interactions.
Technical Performance Analysis
Technical training deals with developing a required skilled movement for a given sport, and usually consists of performing closed (predetermined) drills while observed by a coach. All technical movement should be executed according to key performance points with an emphasis on repeating key movement patterns accurately for a sufficient number of times to convert a cognitive motor pattern (requiring coordinated concentration) into an autonomous one requiring little conscious effort.
Technical attributes vary greatly depending on the sport, but in football an example would be:
- Ball control
- Turning skills
- Travelling with the ball
- Passing over varying distances
- Attacking and defending skills
- Finishing skills
- Aerial ability.
Tactical Performance Analysis
Tactical training is concerned with sport-specific decision making and reaction to situations, as well as the strategy and game plan for a chosen sport. This is usually trained using open drills requiring a reaction to an external stimulus, forcing the athlete to respond. Tactical training puts the technical tools to work. It pieces together connecting techniques in response to an opponent's reaction and the rest of the team’s position.
An elite athlete should have a comprehensive knowledge, understanding, and experience of the following tactical attributes:
- Recognise and adapt to the state of the game
- Achieve winning performances by maximising strengths and exploiting weaknesses
- Understand and apply individual, unit and team roles and responsibilities
- Adopt varied playing styles and formations
- Perform effectively against varied playing styles and formations
- Deal with varied environmental conditions.
Physical Performance Analysis
Physical training prepares the athlete to perform maximally in their sport and not only builds appropriate strength, power, endurance, agility, stability and mobility, but also develops the coordinated movement required for technical mastery. Physical training underpins both technical and tactical performance by ensuring that an athlete can physically execute the technical movements and strategies at the required intensity and duration.
To perform at an elite level, an athlete must have the performance capacity to optimise the following physical attributes:
- Agility, balance, coordination
- Speed/Speed endurance
- Nutrition and lifestyle
- Physical resilience
Psychological Performance Analysis
The psychological training focuses on how an athlete performs in mentally-challenging situations and relates to an athlete’s will and motivation to reach their objectives. Being able to collect and communicate subjective information on an athlete’s psychological state is a huge part of performance management, and assists in finding patterns that predict physical output, as well as helping bridge any communication gap with your athletes.
The mental, and social, component of elite sport can be categorised with the six Cs: