Whatever it was, I had a pretty good ride today. It wasn't cold or raining, and the wind wasn't bad. I worked on 40/20 intervals, i.e. go as hard as I can for 40 seconds + go easy for 20 seconds. Three repetitions is one set, and I did three sets. By the last one my legs sure were feeling it! They need a talking-to from Jens Voigt, I guess.