I ran a marathon, I'm in great shape.....NOT!

I really need to get over this "I just ran a marathon...I'm in great shape!" mentality.

Two factors led me to the YMCA for a little workout this morning:

1.  It was weight watchers weigh-in day and I was very close to being up for the week.  So I needed a little last minute sweat to help me out.
2. I'm registered for the Door County Triathlon in July, so I'd better get back into some sort of a training mode.

I did 13 minutes on a stationary bike, after which I felt like my legs might fall off.

Then I ran for a total of 11 minutes on the YMCA track.  I may not be able to walk in the morning.

What happened?

Apparently three months of doing absolutely nothing wipes out all gains made training for and running a marathon.