I want more chess energy

A few days ago I played my first otb chess tournament since 2006. I had not played more than 1 90 30 game in a day since 2006. I found this very, very hard to get used to. My first game was an 86 move draw. That went for 3 and a half hours. When I came back in the afernoon for my second game my quality of calculation went off the boil. I still wanted to play. But my mind was like a petrol pump that had nothing left to give.

So in the end I won and drew my two morning games and lost my 2 afternoon games quite badly. THe strength of my opponents was about the same.

Where do I get more chess energy? Will I get more by just having had this experience? In the first game I used up about 10 games' worth of energy in adrenalin - after all it was my first serious otb chess game for 6 years.

I have even thought about modifying my chess style in afternoon games. I am a positional player who gets long games. Maybe I could bash out some boom or bust gambits to try to finish a game quickly?

I like 90 30. It is my strongest time limit. That makes my tired games frustrating.

I want energy.

Sigh. I could get a massive oil rig and look for energy...

I think playing more and more OTB matcheswill probably be the best way to increase your chess "stamina".  I experienced the same thing.

The most frustrating thing about the first game was that it was a drawn ending and I offered a draw. He refused and played on for another 40 or so moves until he offered a draw. It was always a draw. Shredder told me that afterwards as well. It was about 6 blocked pawns each and I had a knight and he had a bishop. But the bishop was slightly better in an openish position so I had to take some care - I couldn't take my foot off the gas.

What can I do if these people want to play out such drawn endgames? I mean, I can't make an offer that's too good to refuse.

Estragon, I used to play my Novag for 7 hour stretches when I was 14. Getting a bit low in stamina these days though - Ronald Reagan isn't the US President anymore and there's no A Team or Dallas...