Currently very sick and tired, and yesterday after work I rode to the grocery store. Once you really start it is just as easy to get on the bike, sick, tired, sore...and usually for me the 1/2 hour after my ride I feel my best and most energetic. Then I get around the bummer people and they all bring me back down to earth, so I start looking forward to the ride home. Start listening to books on your commute, it makes it a funner go sometimes.