First solo flight

Last year when I started cycling, I was always amazed hearing people and watching people sustain 20mph for a considerable distance. This year I was able to do that for a 22 mile ride, but it was with 2 other riders, so I didn't have to do all the work. Yesterday I thought I would go on the big chain ring again for my 17 mile ride and see what happened. The route has a nice set of rolling hills in it and some flat. For the first time I held 20.4 mph without the assistance of a draft or any other considerations. When I got home I thought I would try a run, but that pipe dream quickly went out the window as my quads had truly been pressed. I could have run, no doubt about it, but I just didn't want to overdue it yesterday. Today I went out in the heat and humidity of 1:30 in the afternoon and did my 4.72 route, and at mile 3 I felt my quads weakening. I really worked them yesterday and it felt good. I was still able to run a comfortable 33:49 today, but I there was no doubt I biked yesterday.