Chess players burn calories primarily due to the intense mental stress and physiological responses during tournaments, rather than physical movement.

• According to Robert Sapolsky, a Stanford neuroscientist, chess players can burn up to 6,000 calories in a day during tournaments. This claim is based on observations of elevated breathing rates (which can triple), high blood pressure, and muscle contractions sustained over hours, similar to the stress elite athletes experience

. For example, grandmasters like Rustam Kasimdzhanov have lost significant weight (17 pounds) during championship matches, supporting the idea of high calorie expenditure under stress

• However, this 6,000-calorie figure is controversial and not directly measured by standard exercise physiology methods. Studies using indirect calorimetry, the gold standard for measuring energy expenditure, have found only a modest increase in calories burned during chess compared to resting. Troubat et al. (2008) reported chess players burn about 1.67 kcal per minute playing chess, versus 1.53 kcal per minute at rest-a roughly 10% increase. Over an 8-hour game, this would amount to about 960 calories, only slightly more than sitting quietly

• Other research shows a typical chess player burns about 132 calories per hour, or around 1,188 calories during a 9-hour tournament day, similar to other sedentary activities

. Grandmaster Mikhail Antipov was tracked burning 560 calories in two hours of play, comparable to running 5 miles

In summary, while chess players do burn more calories than resting due to mental stress and physiological responses, the widely cited figure of 6,000 calories per day is likely an overestimate without direct measurement evidence. More reliable studies suggest a calorie burn closer to 1,000–1,200 calories during a full day of tournament play, still significant given the sedentary nature of the activity