Understanding mental fatigue

If you’re going through hell, keep going.


As chess players, we get tired as we play long games, and are more likely to make mistakes when tired. What is fatigue? How to slow down the onset of fatigue? Let’s have a look at the bio-psycho-social model of endurance performance.


How we act when going through strenuous effort is affected by physiological and psychological factors. Let’s describe things as simple as possible.

The perception of effort is how hard it is for us to be focused and play. This goes up with time. Calculating long lines with clarity is initially easy, but how easy is it after 2 hours? After 4 hours? After 6 hours? It gets progressively difficult. For a runner, the runner would simply stop running, the ‘stopping’ point for chess is more difficult to define, let’s simply say that we can’t perform the calculation satisfactorily anymore. 

Motivation is the next critical component of the model. If a player is in a must-win position on the last round of an important tournament, they will be more motivated. You will call it quits more quickly in an informal analysis session than playing a world champion in a simul.

The following graph shows the time to exhaustion, which is basically the amount of ‘good play’ available. This will be from one to many hours.


Raising motivation is one way to increase the amount of good play available. This is in a way also a difficult variable to modify as it depends so so strongly on external factors. Self-talk and imaging techniques are available to bring a player into ‘the zone’ but it won’t alone bring world-champion championship-level motivation. There are limits to imagining that your long Sunday jog is the marathon des sables. 

Perception of fatigue

Physical fitness

Physical fitness, physical fatigue, and mental fatigue are intimately linked. This is a subject of fascinating neuroscientific research and I link below a chess dojo where Kostya allowed me to bring in and interview researcher and expert Jeroen Van Cutsem (this is also available in podcast form). 

What we need to know: physical fitness does help with mental fatigue. Do a sport, move around, the best kind of exercise is the one that you like to do regularly

The elephant in the room: training

How to reduce the perception of effort for running? Start running regularly. How to reduce the perception of effort for chess? Play chess regularly. But let’s be clear about the principle of specificity here: you need to train for the effort you have to make. Watching 2 hours of youtube videos is not the same as calculating for two hours straight. It would be unrealistic only to run short distances and expect to run a great marathon. It is equally unrealistic to expect to play well for 5 hours straight OTB if the hardest playing or analysis session beforehand was 1 hour. Players need to train mentally in a challenging way so as to withstand the high demands of competition. What is the closest activity to playing classical time control? Analysing games and solving studies: the timeless advice of the soviet school of chess. No surprises here.

I need to mention the use of psychological techniques like positive self-talk to be quite efficient in reducing fatigue in endurance sports. Especially third person “you can do it” is more effective than first person “I can do it”. This topic crosses over to the general psychological preparation of the chess player. 

The exogenous aids

There is evidence of creatine helps push mental fatigue as it is a direct source of energy for neurons (there is now new evidence of it improving memory). 

Jeroen discusses various things such as swirling caffeinated drinks in one’s mouth (and spitting!) or the role of smells. These are I think not as impactful as the other main topics discussed here

Summary of key takeaways

To improve mental fatigue, decrease the perception of effort. 

  • Do long training sessions (analysis/calculation work)
  • Do regular physical activity and build physical staminaDoing this will bring you 95% of the way. If you chase marginal gains, then consider extra techniques like creatine supplementation.

To learn further

Dojo Talks: Mental Fatigue


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