Fatigue in football: it’s not a brainless task!

At the top level, football is highly demanding, with players enduring substantial pressure to perform at their best every game. Indeed, the congested match fixture schedule combined with heavy performance expectations, exposes players to significant physical and psychological stress. Combined, these stressors can result in fatigue which can affect performance.

Fatigue is a complex state with a multifactorial genesis. Traditionally, fatigue in a football context has been investigated from a neuromuscular/metabolic perspective (Bangsbo, Iaia, & Krustrup, 2007) with relatively little scientific attention examining the impact of mental fatigue on performance. Most commonly, fatigue has been studied within the constraints of physical performance during competition and it has been reported to manifest in reduced distances covered towards the end of the match, and/or following high-intensity periods during the match (Carling & Dupont, 2011; Mohr, Krustrup, & Bangsbo, 2003). Moreover, reductions in quantity and quality of technical performance during match-play have also been suggested to result from “match-related fatigue” (Rampinini et al., 2008).

However, with the exception of military combat, it has been suggested that team sports such as football place more stress on the brain than any other activity (Walsh, 2014). Indeed, football players are required to remain vigilant for long periods before and during matches, adhering to tactical strategies, constantly adjusting to changes in the opposition and their team mates. Players are also required to make quick and accurate decisions accounting for these factors, constantly retrieving and processing information in a dynamic environment. In addition, players have to cope with the mental stressors resulting from the expectations of coaches, supporters, sponsors and media. Therefore, it is likely that players experience mental fatigue in their daily environment and this can negatively affect performance.

Until recently, relatively little was known about the effects of mental fatigue on football performance. However, recent studies have shown that mental fatigue can affect many aspects of football performance, including football-specific running (Smith et al., 2016a; Smith, Marcora, & Coutts, 2015), technical/skill (Badin, Smith, Conte, & Coutts, 2016; Smith et al., 2016b) and decision-making (Smith et al., 2016b) performance. Whilst these studies have induced mental fatigue using methods of low ecological validity (e.g. Stroop tests), they have clearly demonstrated that mental fatigue should be considered when preparing footballers for competition. Indeed, since both mental and physical fatigue have been reported to negatively affect physical and technical performance and increase the risks of injury, managing fatigue is now a major part of scientists’ work in football. In the field, monitoring both perceptions of fatigue and physical fatigue is a common practice. However, more work is required to help us understand the best ways to approach mental fatigue. For example, should athletes be trained under high levels of mental fatigue to prepare for the increased demands of match-play, especially during periods of congested match fixtures or leading in to important matches and championships?

Certainly, examinations into fatigue and its consequences will continue to be a fertile area for scientists working in football. Accordingly, the Journal of Sports Sciences: Science and Medicine in Football welcomes further work in this area. This additional work is required before we can unpack the complex interactions between fatigue – both physical and cognitive – and total football performance.

Disclosure statement

No potential conflict of interest was reported by the author.