To stay focused during long live sessions, I mentally prepare myself before even sitting down at the table. A good night's sleep, a light meal, and remind myself that I'm playing for the long haul.
During the session, I avoid getting distracted: I stay attentive even outside of
hands, I analyze other players' patterns, and I take mental notes. It's like a little game within the game to keep my mind active.
If I feel my concentration slipping, I get up, walk around a bit, and drink some water. A two-minute break can save hours of bad decisions.
And above all, I manage my emotions. I don't panic after a bad beat, nor get euphoric after a big pot. I stick to my plan and remind myself: "My only goal is to play every spot well."
It's a real mental workout. But the more seriously you play, the more natural it becomes.