Chess Grandmasters Burn 6,000 Calories on Tournament Days

Two other ways to see how Chess players aren't using 1000's of kcal per day above their BMR. If it were true:

1. Chess would be an outdoor Winter sport played in shorts and breathable vest.

2. A Tiktok influencer would already have achieved worldwide notoriety by promoting Chess as a weight loss trend.

lol

My second highest day was a little over 5,100 calories with a 10 mile run (some walking) and around 20 additional miles of walking. For 60 miles I would burn a lot more.

While the tracking isn't as accurate as a closed metabolic ward or direct tracking of gas exchange, it's probably not off by a lot (based on continuing usage and tracking weight gain/losses). My BMR is closer to 2000 calories, maybe a little more

As to playing chess, my heart rate at times can get into low zone 2 and I do sweat. Breathing isn't elevated too much.

I almost always lose weight after a tournament. That's even with sufficient calories, earlier and after the games of the day, to exceed my BMR (2,500 calories+ in some instances)

This doesn't sound plausible either. Do you have a source for it?

If it were correct we'd have real difficulty keeping our head cool and/or the rest of our body warm.

This estimate seems good. 2000 for your BMR and 3000 for 30 miles on foot is about right.

At 50 kcal/h, I would expect your breathing rate while playing a Chess tournament to be about the same as if you were to walk at 0.5 mph. Slightly elevated from resting but not noticeably so.

I think your tracker is good at translating your heart rate to energy usage while exercising, but gets thrown off when your heart rate rises for other reasons. It is marketed as an exercise tracker after all.

Heart rate isn't always well correlated with energy usage and your tracker probably has some documentation explaining that. Many factors can influence how well it correlates. In the case of your Chess tournaments, your heart rate is probably elevated by mental stress much more so than your body's increased energy requirements.

This likely explains where the original mismeasurement of 6000 kcal originated too.

I've always read it's around 20%

It's not just the calculations but my weight changes usually correlate very well with those expenditure estimates. After a long day of chess being physically fatigued is also not uncommon. Increased heart rate over longer spans, in addition to stress, all likely increase metabolic activity. As long as the stress isn't chronic anyway

Even if you did use an excess of 3000 kcal in a day, you wouldn't be able to measure it in body weight easily against the background of normal fluctuations.

You'd have to take into account hydration levels, water retention, glycogen water binding, the contents of your digestive tract, etc. which could fluctuate by up to 10 times the weight lost from 3000 kcal of stored energy.

Doubt it's anywhere close to that, just like how e-sports/video game players aren't burning a lot of calories. You're sitting down exerting little energy, maybe if you were walking on a treadmill for the entirety of an 8 hour classical game by the end of the entire day you'd of burned somewhere close to that, definitely not playing regularly. It's like saying you're going to eat 3 large pizzas and then burn off the calories playing chess later

I weigh almost every day and am very aware of what my normal fluctuations look like and how various food choices generally impact it as well. Most of the time it's not going to be glycogen water retention either, which is something I'm also very aware of based on dietary choices.

I consistently see similar results after most tournaments I play. I can usually pinpoint fluctuations based on physical activity as well, though I do have occasional outliers.

Heat dissipation and oxygen intake aside, I'd be surprised if it's even possible to use 3000 kcal of stored energy in a day without exercise. Well rested, you have about 400 kcal stored in your liver and 1600 kcal in your muscles. Once that's gone you'll experience extreme fatigue and hunger. The energy stored in muscles isn't very mobile so wouldn't be much use to you while playing Chess. That leaves body fat and muscle mass and it's doubtful that you'd be able to break them down fast enough.

Also, a calorie deficit of greater than 1000 kcal per day is dangerous so Chess would require health warnings.

Yes, yes. I am absolutely sure that the Stanford University research is wrong and you are right. You showed them.

Finally, I found my solution to being overweight. I just need to play more chess!

Obviously this much calories don't go in chess. A lot of them are actually burned as heat. Probably that guy accidently counted the calories which were released as heat. Even a gym workout won't burn more than 600 calories.

Robert Sapolsky has clarified that he has been misquoted by the media regarding this and there is absolutely no evidence for "6000 calories."