Once, the YouTube "algorithm" led me to video featuring a bodybuilder that explained that being a professional bodybuilder = being a professional eater.

To bodybuilders (and I assume, also athletes), eating in a methodical and structured way is an important part of their job. The guy grew his own vegetables and spent a lot of time selecting food at markets, ate at very specific times, etc.

That, combined with supplements, experimenting with different training regimes, etc... it's a lot of experimentation and certainly there's a lot of cognitive work behind all of that.

I found this very interesting.