Chess players burn up to 6000 kcal per day: here's what happens to the body

In recent years, a claim has been actively spreading on the internet that chess players burn up to six thousand kilocalories per day during tournaments. This figure causes bewilderment and admiration: how can a game where a person sits at a table and moves pieces compare in energy expenditure to a marathon?

Let's try to understand where this information came from and what's behind these numbers.

At first glance, chess is an absolutely calm sport that doesn't require physical activity. However, it's not that simple. Chess tournaments involve many hours of mental and emotional strain. Players are in a state of constant concentration, planning, analysis, and stress. This is especially true for major championships, where the price of each mistake is defeat and elimination from the tournament.

Some sources claim that chess players can burn up to 6000 kilocalories during a day of competition. This figure is most often cited in media and blogs but is rarely supported by scientific data. Initially, the idea came from observations of the behavior and physiological state of grandmasters during matches. Increased heartbeat, rapid breathing, sweating, noticeable weight loss by the end of the tournament - all this gave reason to assume high energy expenditure.

However, more accurate scientific measurements show that it's not so dramatic. Using indirect calorimetry, a method that determines energy expenditure by the level of oxygen consumption, it was found that the average activity of a chess player during a game is only slightly higher than that of a person at rest. Energy expenditure can reach approximately 1200-1500 kilocalories for an intense day, but not six thousand. This is because the brain, although requiring a lot of energy, cannot compare in expenditure to muscle activity during running or heavy training.

Why do chess players actually lose weight during tournaments? The reason is not only energy but also a complex of other factors. First, stress. It can suppress appetite, cause insomnia, increase the production of cortisol and adrenaline. Second, the sedentary lifestyle during matches is accompanied by increased nervous tension, which affects overall well-being. Third, many participants limit their food intake, drink less water, and sleep poorly during competitions. All this can cause weight loss, which is mistakenly perceived as a consequence of "colossal energy expenditure."

Interestingly, some modern chess players do indeed train physically to maintain endurance, attention, and resistance to stress. Physical fitness helps them better endure long games. In this sense, chess is becoming closer to classic sports, where not only intellect but also the body is important.

Thus, the idea of six thousand burned kilocalories is a myth, embellished for impression. In practice, chess is indeed an energy-consuming mental activity, but its contribution to calorie expenditure is limited. Nevertheless, professional chess players do experience serious strain - it just manifests differently than in a gym.