I work out twice a day. It's the best way I've found to keep myself sane and productive. I've never taken any drugs but I'll sleep 10+ hours a day or get ridiculously jittery if I don't.

And I've also found that I am most productive if I have a coffee exactly at 6AM and 3PM.

I have spreadsheets to track my sleep and caffeine consumption with respect to productivity. Classic signs of ADHD.