1.  Rate your performance on a 1-10 scale with 10 being the best.
2 . Explain the rating.
3.  List any injuries and/or physical factors - good or bad.
4.  List any mental and emotional factors - good or bad.
5.  List any environmental factors that influenced your race - good or bad.
6.  Briefly describe the start, the middle, and the finish of the race.
7.  List any mile splits.
8.  Discuss ways to improve your performance.
Update your log soon after each race.  
You are documenting your endeavor for posterity.
It should not take more than 15 minutes.
Race recaps are required for PE credit.