I had some very demanding days.
Traveled with packed bags(10kg) across Germany with trains, which took me 15 hours, then slept 6h.

There I went to this super cool congress/convention/event(39c3) with all these queer people, hackers and a lot of leftists. At this event I walked between 15-20k steps everyday with my backpack.
I put multiple RGB LEDs with powerbanks on it and took it with me to show it off to anyone. In the evening I danced most of the days. And while I could not sleep very good at the hotel my muscle aches were minimal and I always had energy to do stuff.

I am baffled. So this is what I get from gradually, over the last 12 months, to pushing myself to lifting weights 4 times a week.

This is awesome!