I would be in the "depends on time of day" crowd. Morning, which is when I usually ride since I work second shift (3pm-11:30pm), I feel worn out until I hit the 5 mile mark, then I feel I could go 20 miles, but remember I need to go to work. And, since I make precision optics, I gotta be alert and not too phsyically drained. Weekends, I do most of my riding later on, after lunch or a good breakfast. I can do 20+ miles then and am ready to go right from throwing my leg over the bike.

Speaking of work...anyone notice they feel more lively and accomplish more at work after riding? If i keep my pre-work ride to 5-10 miles I feel energized.