[alanmcorcoran]

With the exception of the "days when you feel great" part, I recognize these symptoms. I haven't had them too much on the bike yet, but I have had them doing other activities that require focus, concentration and some coordination (skiing, playing the piano, racquetball, lifting weights.)

For example, one day I just could not get 185 pounds back up into the rack. I'd been lifting that much (6 reps) and more for a year, but, for whatever reason, I just didn't have anything. Had to dump the weights off. Ended up lowering my whole routine since then cause you don't know when it will strike. There are days I just get up and walk away from the piano cause I just don't have it and I'm not only wasting time, but practicing (learning) bad habits. There are days on the mountains where I can ski anything at full tilt and others where I am afraid to get off the lift.

I chalk it up a little to age and a little to a natural waxing and waning of one's abilities. It's sort of the opposite of being in the zone. When I was training for marathons, there were days I could run nine minute miles (fast for me, slow by most standards) for 15 miles. On other days, I struggled just to get through 8 miles at any speed. Over time, I've learned to do less and spend more time resting and recovering.

I ride the bike almost every day, and, yes, there are days I probably shouldn't be on it. On those days, I just lower my envelope of operation and raise my level of consciousness. In truth, for my commute, you don't need to be very adept to get through it. It's very short and very easy.

I have had whole days (and weeks) where I couldn't do anything right: stub my toe, hit my head, miss a meeting, can't remember my phone number, etc. I expect these will come more frequently in the future.

McCain fans, take note! (I am "only" 50.)