Can you avoid exercise if you play chess?

Posted on October 26, 2020

(Last Updated On: October 28, 2020)

ESPN ran an article on grandmaster chess players that got a lot of internet buzz, due to this paragraph,

“Robert Sapolsky, who studies stress in primates at Stanford University, says a chess player can burn up to 6,000 calories a day while playing in a tournament, three times what an average person consumes in a day. Based on breathing rates (which triple during competition), blood pressure (which elevates) and muscle contractions before, during and after major tournaments, Sapolsky suggests that grandmasters’ stress responses to chess are on par with what elite athletes experience.”

Because I’m familiar with Sapolsky, I immediately knew where he was getting this from (it wasn’t like he was pulling it out of thin air), but I have to say, like many, the 6,000 figure surprised me.

I went to his book, searched “chess”, finding,

“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. 1971. Physiological changes during tournament chess. Chess Life and Review, 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. 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. 1987. Hygienic evaluation of the changes in work capacity of young chess players during training. Gigiena i Sanitariia 24, in the original Russian.”

I couldn’t find those original references, but someone got ahold of Sapolsky, where he says the number was an extrapolation from the measurements they took.

The ESPN author also went on NPR and cited an informal heart rate study on chess players, extrapolating heart rate to calories burned, finding 560 calories burned over two hours.

If you know anything about calorie measurements, besides the doubly labeled water method (radioactive isotope measuring), you know to be real careful with how the numbers are interpreted.

I wrote about not bothering with using apps to count calories burned many years ago

We can then find a much more recent, formal, not as good as doubly labeled water but pretty good, study,

The stress of chess players as a model to study the effects of psychological stimuli on physiological responses

Which found in higher level chess players (though not the best of the best), calorie expenditure of up to 2 calories per minute.

So, even if one is playing chess for eight hours a day,

  • 8 hours per day * 60 minutes per hour * 2 calories per minute =
    • 960 calories per day

That’s a long ways from 6,000 calories a day, or 560 calories over two hours.

These were competitive chess players, but again, not the absolute best in the world. But I don’t think there’s a plausible argument players who are, in an absolute sense, a bit better, are going to burn 6x more calories.

I realize some may take umbrage with “a bit better.” Let’s digress for one second-

What often looks like drastic differences in ability in high performers is usually no more than a few percent. I always use this example: Usain Bolt, visually obviously the best, yet only being 1% faster than his competition:

One percent!

Another way to view it:

Chess player A has a 99.95% chance of making the right decision.

Chess player B has a 99.5% chance of making the right decision.

(we’re in the world of a half percent relative difference)

Over 1,000 decisions,

There’s a 40% chance player A makes a mistake.

There’s a 99% chance player B makes a mistake.

This is how it goes at the highest levels of performance. We start worrying about numbers this small, as, over time, they do still add up to large differences.

-> Math:

1 – 0.9995^1000 (player A)


1 – 0.995^1000 (player B)

So, just like we’re not going to assume Usain Bolt is putting out drastically more calories than the person behind him, or just like we’re not going say a person who squats 500 lbs burns way less calories than someone who squats 550 lbs (a 10% difference), I really don’t think we can make that leap with chess players either.

However, I do think anecdotes at the highest level are very important, because that’s really what studying elite performance always is. If nothing else, you can’t get a huge sample size of them to ever call it true science. After all, the definition of elite performers is there aren’t many of them.

So, when these elite players, per that ESPN article, are reporting e.g. 10 pounds of weight loss, I do think that’s relevant. But I’d also be very interested in factors beyond calories burned, like calories ingested. A routine story of someone deep in focus is forgetting to eat. I’d imagine these people are, for instance, not eating or drinking as much as usual during these tournaments, causing some big swings in water weight too.

But let’s not be so dismissive. If you intensely play chess for, I don’t know, 10 hours a week, that can still be over a 1,000 calories a week! That ain’t bad!

Out of what I’ve written, one of the more important topics I feel is in,

New insights as to why you can’t avoid exercising

One takeaway of the article is as the body burns more calories from physical activity, it will, at some point, compensate by burning less calories elsewhere. You’re really not going to be able to, on a regular basis, burn e.g. 1,000 calories a day from an activity to where you can then eat 1,000 calories and expect that to balance out, so you don’t gain or lose weight.

It’s something we can all relate to. Have a hard workout and what do you often want to do the rest of the day? Not move much.

The article also details how this can be going on well outside of one’s control. Burn a bunch of calories with your muscles and later on the body might not burn as many calories for menstruation. Hence, we have very active women who lose their period (no matter how much they eat).

Finally, burn a lot of calories from running, and maybe your body is less likely to use calories to fuel tumor growth, giving some potential rationale for why exercise is linked with less cancer risk.

I’m going to reiterate this, as I’ve seen this topic confuse a lot of people: While you may burn a lot of calories from a physical activity, you eventually burn less calories NOT doing the activity, making it, in effect, to where you never actually burned that many calories. This is one reason weight-loss can only go so fast. The body doesn’t allow itself to be emaciated so easily.

That doesn’t mean it’s not worth burning calories from a physical activity. First, per the article, it takes a while until the body really starts to compensate. Second,  it is worth doing, as, again, you can get health benefits through lesser calorie expenditure elsewhere. It does mean you can’t just think “I burned 1,000 calories! Let me shove my face with junk food!” and expect to lose weight.

The flaw in that article, which I’ve always wondered if someone would figure out but nobody’s mentioned it, so let’s do it now, is the notion the calorie expenditure has to come from physical activity. Maybe it doesn’t!

Because not only can you find similarities in physiological responses in mentally and physically demanding activities, you can find similar outcomes. Namely, traits like increased life expectancy.

Longevity of outstanding sporting achievers: Mind versus muscle

Which found increased life expectancy for grand masters.

Decreased chronic disease prevalence in more regular chess players,


Or the idea United States presidents are so stressed, but paradoxically how long they live.

American Presidents and Life Expectancy

I realize we’re glossing over e.g. socioeconomic factors, which are huge when looking at life expectancy. Still, a well established idea in healthy aging is staying mentally active. All I’m trying to get at here is perhaps one of the reasons for that is an active brain burns more calories. Maybe it keeps the body pumping much like exercise does.

-> Could one reason socioeconomic status be so important in modernity be those with active minds tend to also be those who do well economically?

-> We can get pedantic here. It’s not necessarily the brain burns more calories, it’s the brain causes the body to rev up other functions, like the heart, which burns more calories.

Again, a pretty obvious experience: we can all relate to getting mentally stressed, and that making our heart beat faster, or our muscles tense up, or we start pacing around.

Some other similar outcomes:

  • Division I football players are more likely to get hurt during training camp (when their body is working on overdrive) and during exam periods (when their mind is on overdrive)
  • Med school students are more likely to get sick during exam periods, (similar to runners who overtrain), and, very intriguingly, their wounds heal more slowly. Illustrating that connection between more calories burned in one activity means less calories burned in another activity, but sometimes that can be a negative.

Understanding the divergence between athletic and academic performance

Where there’s also the similarity that some is great, but too much is harmful. Physically exercise too much and you can start to lessen a lot of its benefits. Work the brain too much and obviously we know all the negatives that can come of an overactive brain.

-> This is one reason anybody who trains people -personal trainers, strength coaches- should be well aware of how mentally stressed their clients are. For example, I ask every new client if they have kids, and how old they are. Any client who has small children around, and I know I likely should not be pushing them as much physically. Odds are, they’re already chronically tired.

I think of someone like Warren Buffett. A guy who enthusiastically tells of his 6 year old like nutrition- 6 cokes a day, has friends who tell of him eating Oreos for breakfast, and he has a hamburger for dinner practically every night. Little physical exercise. Yet he’s 90 years old and going strong.

He’s also known for sitting down and reading / thinking most of the day, every day. (Not just 2-3 times a week like how many of us do physical exercise.) After his work day, he plays bridge for two hours a night.

Maybe that mental exercise has been enough to simulate the benefits of physical exercise? (Or, of course, maybe he’s just an outlier.)

There are quite a few people who live quite a long life, never doing much physical activity. Certainly nothing in the realm of “working out.” But I’m not sure you’ll find many people who live a long time who are physically AND mentally sedentary.

Two caveats:

First, odds are, you’re not working your brain like Warren Buffett. We need to remember the context we’re dealing with. I referenced the most respected investor ever, high level chess players, U.S. Presidents, med school students. These aren’t average people; this isn’t average brain engagement. I think everybody has come across somebody whose brain is “always on.” The kind of person who gets excited by having to do something mentally demanding, whereas most, just like physical exertion, shy away from it.

These aren’t people who are watching (the American average of) 4.5 hours of television a day, vegging out on the regular. In fact, I’d argue your average person would rather do 30 minutes of physical activity a day than potentially needing hours of intense mental activity, possibly daily, to get the same effect. (That would be some interesting research- knowing how much mental exercise equated to physical.)

-> This is where someone is definitely going to insert the joke of President Trump apparently watching television half of every day. Even then, I’d argue he’s not watching TV with the intention of sitting back and zoning out. He’s watching it with a purpose, agree or disagree with that purpose (this is not the forum to discuss that), but there is clearly an intention behind it.

In other words, Trump, who is clearly not in good physical condition -he’s actually bragged how little he exercises- well, maybe he’s overcoming that by, clearly, having a very active brain?

-> Television, relative to practically anything else your brain could be doing, has been shown to decrease brain activity. Humans are quite good at finding ways to decrease calorie expenditure. Could this be one reason TV is, one could argue, addictive to humans?

-> Maybe one way to get gauge mental strain: does the mental activity cause one to stop physical activity? For instance, you’re walking, if you really need to think about something, you probably stop walking. If someone asks you 2+2, you can keep walking (it’s not enough mental strain to qualify as working out). If someone asks you 234 + 432, you probably stop walking (where it is enough mental strain to qualify as working out). You might even have to sit down.

Almost like the body is saying “we can either walk at X speed or think X amount hard, but not both.” So then X is the threshold we need to meet?

Second, no matter how much chess you play, it’s never going to significantly strengthen your quadriceps.

That is, exercise still provides all kinds of other benefits that a mentally demanding activity can’t. Sitting down thinking is never directly working on your balance, ability to go up and down stairs, and so on. It’s never going to make your biceps bigger.

What’s amazing about physical exercise is how many indirect benefits you can find from it. Look up practically any ailment, and you find exercise helps it (as does socioeconomic status). That’s where the calorie compensation argument really comes in. That’s more of what we’re getting at here. Bluntly, can mental exercise get you to live as long as physical?

-> Another anecdote: How long Stephen Hawking was able to survive while essentially fully paralyzed but with a mind that still worked, and, obviously, worked in a way most don’t.

But if you’re looking at a direct benefit of exercise, like the ability to run around with your kids, chess isn’t working on that, unless it’s getting you to get your kids to sit down and play with you!

Finally, what that ESPN article was really about is the benefits chess players are finding from…physically exercising!

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