Reading GeneJockey's account above, I wonder what is a typical warmup period of time? I never warm up less than 30 minutes before doing a max effort, usually 40 minutes is about right. I have not done any longer tests this year and plan to do a longish climb tomorrow. I've always saw that I performed better and assumed the legs open up but maybe it is the heart. Also, the longer warmup seems more important as I age. No idea why. Heart? Veins and capillaries take more time to dilate due to less NO2?