They value different things, but this is not uniformly less effort on any physical activity. More than one person from my very rationalist workplace climbs v8 boulders.
Interesting observation. I'm don't have strong feelings about how fit rationalists are compared to the population. I have met various fit rationalists though.
* A few come to mind in the local rationalist community in Portland.
* I remember one guy on the LW Slack being really into weightlifting.
* Over the years, somehow I've managed to meet up with four rationalists who are really into basketball. Perhaps because I've expressed interest in basketball in my writing. It still feels like a somewhat large coincidence though, given the small amount of LessWrongers who I presume to be into basketball. Anyway, each of these people have been extremely fit. 2-3 of them have played at the college level.
* jefftk strikes me as being relatively fit. I vaguely recall posts indicating he spends a lot of time running, biking, dancing, and doing a decent amount of other outdoor activities. Similar with so8res.
* Once upon a time I was pretty fit. Hopefully I can become fit again.
Meta: I disapprove of this being downvoted.
2Dean Valentine
It says what it says. Obviously if there's an actual trend it raises some questions, like whether or not rationalists just tend to care less about their health, or if intellectuals find it harder to come up with internal motivation for eating less. It does seem odd to me that rationalists would be more unhealthy than their general demographic given that being physically fit is a good instrumental goal for virtually everything.