How to Tackle Mental Fatigue
by Doug Stewart
What are the most promising measures to combat mental fatigue?
Mental fatigue (MF) is a psychobiological state caused by prolonged episodes of cognitive exertion that harms intellectual and physical performance. MF decreases accuracy and increases reaction time during cognitive tasks (Rozand et al, 2015). It also deteriorates endurance performance (Van Cutsem et al, 2017). Additionally, technical and tactical aspects in team sports have been shown to be negatively impacted (Habay et al, 2021). As this can lead to a higher risk of injuries and incidents, it is in the interest of every athlete to counteract or circumvent MF.
There is a fair amount of research around how to fight MF, but a systematic literature review has been lacking until now. Proost et al. have recently published a systematic review of potential countermeasures for MF and their underlying mechanisms. They looked at acute countermeasures, classified them by the timing of application (before, during or after the moment of MF) and by type of intervention (behavioural, physiological and psychological) and evaluated their effectiveness.
The researchers looked for suitable studies in scientific databases and found 33 eligible studies.
What they found in general was that a wide range of countermeasures can be applied to successfully counteract MF. Most of them cause a positive effect on behavioural and/or subjective MF markers. No conclusion could be drawn, however, regarding the effect of the employed countermeasures on (neuro)physiological markers of MF.
Four particularly effective countermeasures were identified:
Physiological countermeasures: using pleasant odours during an MF task or taking in caffeine before an MF task are the most promising interventions in combating MF.
Behavioural and psychological countermeasures: listening to music or using extrinsic motivation seem to be good interventions to offset MF.
The researchers suggested that, due to the heterogeneity in the protocols, it was difficult to draw firm conclusions. There was a wide variety in the discussed countermeasures, and it may be difficult to choose which countermeasure is the most useful, effective, and easy to use within a specific setting.
For example, during a long run or bicycle ride with no possibility to take a break, an easy-to-consume nutritional countermeasure could be the preferred option to counteract MF. On the other hand, when competing in a tournament with multiple rounds (e.g., tennis), behavioural interventions such as listening to music could be most useful.
If MF is likely to occur within hours, the most appropriate countermeasure would be a 5mg per kg of body weight dose of caffeine, a caffeine-maltodextrin mix, or cocoa flavanols. But you should also be aware of the potential unintended side effects of such nutritional countermeasures as they might lead to gastrointestinal distress. Using odours to overcome negative effects of MF is proven to be effective, however, it might be impractical in sports such as running or cycling as the odours will evaporate. Although, you could use this countermeasure in an aid station or apply it on your clothes or body.
One of the most practical interventions in overcoming MF is the use of motivational stimuli. The difficulty there is finding the adequate motivational determinants as this is individual dependent.
The study authors also suggested that the use of 20 minutes of binaural beats and long-term mindfulness are good to recover from MF. In addition, these do not require extra material and are easy to implement in a training regimen.
So, in essence, there are plenty of options to counteract mental fatigue and to recover from it, but the real challenge is to find the adequate countermeasure for each individual and for each setting.
References:
Proost M, Habay J, De Wachter J, De Pauw K, Rattray B, Meeusen R, Roelands B, Van Cutsem J. How to Tackle Mental Fatigue: A Systematic Review of Potential Countermeasures and Their Underlying Mechanisms. Sports Med. 2022 May 11. doi: 10.1007/s40279-022-01678-z. Epub ahead of print. PMID: 35543922.
Rozand V, Lebon F, Papaxanthis C, Lepers R. Effect of mental fatigue on speed-accuracy trade-off. Neuroscience. 2015;297:219–30. https://doi.org/10.1016/j.neuroscience.2015. 03.066
Van Cutsem J, Marcora S, De Pauw K, et al. The efects of mental fatigue on physical performance: a systematic review. Sports Med. 2017;47(8):1569–88.
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Habay J, Van Cutsem J, Verschueren J, et al. Mental fatigue and sport-specifc psychomotor performance: a systematic review. Sports Med. 2021;51(7):1527–48. https://doi.org/10.1007/
s40279-021-01429-6