I always had trouble knowing what kind of shape I was in at any given time and be able to predict performance. Three weeks ago we went down to Weston to run the Prom 5 miler. Its a flat course out and back twice. It was raining so the numbers were down a little. I set out too fast and by halfway was struggling and slowing with oxygen debt. However I hung in and finished with what turned out to be a (recent) pb with 37:43.