This reminds me of how some people argue they actually drive better when drunk.

Many studies have proven that:

1. Driving ability is impaired by alcohol consumption (or lack of sleep, incidentally)

2. People are very bad at estimating how severely impaired they are (wrt being drunk or kust tired)

Are there any similar studies around ability to mentally focus / perform physical activities while fasting?

I'm confused. You say "same", so you agree with arunix and jraby3? For them their level of hunger increased the longer they fasted. But then you wrote "wasn't particularly hungry", so you agree with franciscop?

Impressive if you did training while fasting btw!

I should have been more clear. For me at least, the peak hunger point was approximately 48hrs. It subsided substantially from there. I am fit and train often. But I've had a life long unhealthy relationship with sugar, which I managed to solve some months after I started fasting.