There exist people that bicycle from San Francisco, to the lighthouse at Point Reyes. To those people i say, "How the hell?" I rode from the sunset (35th and Lincoln) to Sausilito, a scant 18 miles round trip, and was pretty well wiped out by the time i made it home (in spite of an hour for repast).
I haven't been on the bicycle in probably three or four weeks, so that may explain some of my lack of conditioning. Still, my commute doesn't have any ascents comparable to the one to the Legion of Honor (from either direction, but especially the one through the Presidio going south) or the climbs from the water up to the bridge on the north side.
I hope to make this a regular ride, and maybe add Antonio to the back of the bike for a little extra exercise.