went for a group ride this morning that started at 5:30 which was billed as a 25 mile round trip ride. It kicked my butt the last 5 or so miles, I haven't hardly ridden in over 6 months and boy did it show. This was the first time in a long time that I wished for red lights in the last part of a ride and I didn't get any. When I got to the truck and loaded my bike the rear tire felt very soft but didn't think anything about it, when I got home and unloaded the bike the rear tire was flat. I'm blaming the exhausting last 5 or so miles on my rear tire being low on air and not me being out of condition.