Long Session Leakage

[airogent4]

I play 5 tables of .5/1 100max Pokerstars. I've recently started using an excel spreadsheet to track my earnings session by session, with time of the session as one of the variable that I input. It seems that my hourly rates are far better on shorter sessions. Although I do not have the number of sessions necessary to make this statistically significant, it's a pervasive trend nevertheless.

Anecdotally, today I went up big in the first hour, then proceded to leak most of my profit back on to the tables over the course of the next 2 hours.

Does anyone else notice this, or have a possible solution to my woes? I don't think I'm tilting. Any thoughts would be great.

[astroglide]

my short sessions are more profitable too, but i suspect this has something to do with continuing to play when down and leaving when up. if i smoke a ton of money in the first 15 minutes of play, i can end up playing for hours.