[allhailkatt]

I do, but I also have fibromyalgia, which makes me an atrocious point of comparison. But that does mean I've gotten a lot of experience working around physical and ergonomics engineering.

Intense mental work can drop your blood sugar and oxygen content in your blood, as mentioned by others. Start checking your health and engineer health back in for better coding.

Walking to another floor's bathroom, stepping away from your desk to walk around the building, getting a sit-stand desk, regularly stretching... there's a bunch. Get a tracker, and start experimenting. The same thing for nutrition.

If you haven't, work on deep breathing exercises and consider getting a pulse tracker so you can find a pattern. This is any other data pattern, the effects are just very close to home. If you feel like you should be coding, consider if your life was a resource management game and at what point you would expend resources to get better productivity from your base unit (aka. you).

Good luck!