I heard once that when two Chess Grandmasters play a five hour game of chess, the intense concentration and focus they have causes their bodies to burn as many calories as someone playing a sport during that time, such as running.

For example, Dr. Robert Sapolsky claimed that:

… [with] chess masters in the middle of a tournament, they are going through six to seven thousand calories a day thinking. [They are] turning on a massive physiological stress response simply with thought and doing the same thing with their bodies as if they were some baboon that’s just ripped open the stomach of their worst rival — it’s all with thought.

Is there any truth behind this?

Running for that long would be the same as running a marathon, and I just don't believe that sitting playing chess can use as much energy. However I do believe that it must burn more calories then usual.

  • 3
    If i am not wrong, grand masters burn calories from stress not pure thinking
    – Andrey
    Jan 11, 2012 at 14:27
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    it may be that the chess masters were "going through" (per Sapolsky) 3000+ calories per day through intake. Nov 10, 2012 at 10:56

3 Answers 3


People have used chess as a model for studying stress responses and therefore have done a detailed metabolic analysis. The key data is in table 1 (p. 347); here it is, reformatted and converted to Calories/hr:

Energy expended (Cal/hr) Before      Beginning   Middle      End
------------------------ ----------- ----------- ----------- -----------
Mean                      91.8       100.2        91.8        93.0
Minimum                   68.4        70.8        70.2        68.4
Maximum                  120.0       132.0       120.6       122.4

These are comparable to light physical activity (desk work, etc.), and not even close to jogging (400-500 Calories/hr for someone weighing ~70 kg).

So, no, chess grandmasters do not come anywhere close to runners when it comes to caloric expenditure. Extremely stressful games could perhaps exceed even the maximum bounds here (the participants were competitive chess players, but not at the master/grandmaster level).

(Also, note that if chess grandmasters did burn that many calories, they would get at least as hot as runners do, and although you may seen top chess players mop their brow, you generally don't see them in light clothes sweating profusely even in cold weather.)

  • While I agree with the rest of your comment, I have to dispute the last bit about sweating. Heat is generated as a side effect to burning calories; and usage that involved movement probably generates more heat than usage by the brain, where resistance as signals travel through the tissue can be the only source of heat buildup. Additionally, the brain is mostly constantly operating - it may spike at times of extra stress, but while people have a lot of muscles idling most of the time, we don't turn our brains off in the same way; hence, they can deal with heat over a long period of time better.
    – user10765
    Dec 22, 2012 at 8:02
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    @Fadeway - I don't think you understand my comment. Burn lots of calories => you get hot => you sweat. Chess grandmasters don't sweat profusely, therefore they must not be that hot, therefore they must not be burning as many calories as runners. That's it. (I am well-acquainted with glucose metabolism in neurons, but you needn't bring in anything so specialized to answer the question of whether chess burns as many calories as running.)
    – Rex Kerr
    Dec 22, 2012 at 14:48
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    Energy can't be destroyed, and since the brain doesn't do physical work on outside objects, all the energy it uses must be released as heat. Muscles convert part of the energy to physical work and part of it to heat.
    – bdsl
    Aug 22, 2014 at 14:14
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    @bdsl - Hence my "at least as hot" phrase at the end of my answer.
    – Rex Kerr
    Aug 22, 2014 at 19:02

Mental effort does not significantly increase the amount of energy used by the brain.


the brain accounts for about 20% of the oxygen and, hence, calories consumed by the body. This high rate of metabolism is remarkably constant despite widely varying mental and motoric activity.

Average base metabolic rate for men is 1632 kcal per day, so the brain uses around 320 kcal per day.

Running uses around 100 kcal per mile, so running a few miles will use more energy than your brain does during an entire day.

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    This does not really answer the question. Playing chess is more than just thought. There is a physiological factor to it as well. If you get your heart rate up your metabolic rate increases. The brain may not consume more calories but your body does.
    – Chad
    Jan 11, 2012 at 18:19
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    @Chad: especially when playing chess for 5 hours...
    – nico
    Jan 11, 2012 at 20:45
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    @nico: Just to note, a 5-hour grandmaster game is pretty normal. Excessive would be 8-hours per-side, as one world-championship match was... Jan 11, 2012 at 22:54
  • interesting, but wouldn't this compare to any activity that requires excessive concentration (i.e programming for 5 hours)
    – isJustMe
    Jan 11, 2012 at 23:03
  • @Chat: Some anecdotal evidence: I've played in chess tournaments where I've had to play two up-to-six-hour matches each day. It was exhausting, certainly, but not the way I've felt after an hour of full-court basketball. Moving the large muscles (not just the heart) does take more energy and burns more calories.
    – Robusto
    Jan 13, 2012 at 3:14

Sapolsky gives a quick version for the commencement speech. In his book, Why Zebras Don't Get Ulcers (PDF), this is explained in further depth. It's not that the brain burns 6-7000 calories a day, it's the various stress responses in the body that are on the whole greatly on par with top athletes. You need to be in really good shape to play high level chess.

His sources are a thesis by American scientists in the 70s and a book on chess science and Soviet scientists in the 80s, IIRC. It checks out.

The thesis and book were a pain in the ass to find electronically, and I'm not about to do that again now -- I can bring it about later. Although his notes in the book are a start that at least makes his claim plausible:

The definitive study on chess players was carried out by the physiologist Leroy DuBeck and his graduate student Charlotte Leedy. They wired up chess players in order to measure their breathing rates, blood pressure, muscle contractions, and so on, and monitored the players before, during, and after major tournaments. They found tripling of breathing rates, muscle contractions, systolic blood pressures that soared to over 200—exactly the sort of thing seen in athletes during physical competition.

See the original report, Leedy’s thesis, “The effects of tournament chess playing on selected physiological responses in players of varying aspirations and abilities” (Temple University, 1975) or their brief report (Leedy, C, and DuBeck, L., “Physiological changes during tournament chess,” Chess Life and Review [1971]: 708).

In a telephone conversation, DuBeck also tells the story of the international match in the early 1970s between grand masters Bent Larson and Bobby Fischer, in which the former had to be given antihypertensive medication in the middle of his losing match; his blood pressure remained elevated for days afterward.

The Kasparov-Karpov report is from the New York Times, 20 December 1990. And for that special chess fan out there who just can’t get enough of this subject, may I suggest as the perfect gift a copy of Glezerov, V., and Sobol, E., “Hygienic evaluation of the changes in work capacity of young chess players during training,” Gigiena i Sanitariia 24 (1987), in the original Russian.

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    Welcome to Skeptics! Please explain where in the book he makes the claim. Please explain where you got this text. I can't find anything in the book or in the quoted text regarding calorie burning by chess players.
    – Oddthinking
    Dec 21, 2012 at 23:12

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