[serf]

>Contrary to the common myth, thinking hard does not burn significantly more calories. (Demonstration: Start thinking hard, and watch as your heart rate does not increase.)

this is wrong [0] , it's just hard to measure.

[0]: https://pubmed.ncbi.nlm.nih.gov/32314956/

[npilk]

Interesting. I had heard that chess players burn a crazy amount of calories during tournament matches, but when I looked it up just now it seems like that isn't true: https://statmodeling.stat.columbia.edu/2025/06/30/its-sapols...

[Aurornis]

The original claim is not wrong. Thinking hard does not burn significantly more calories.

If it’s really hard to measure because the amount is so small that it requires precise equipment, it’s not significant relative to the rest of the body’s energy expenditure.

[kbelder]

The increase due to thinking hard is small, but still, the amount of energy burned by your brain is very significant. It consumes around 20% of the total calories your body burns. It just doesn't spike due to intense concentration or mental activity.