I did my first metric century about a month ago and have spent the last month with weak thumbs, leading to difficulty buttoning shirts, holding pens, etc. I'm fine now; thumb strength is almost fully restored.
Through my (admittedly risky) internet self diagnosis, I apparently had Cyclist's Palsy.
It resolves in a month or so, without further aggravation of the ulnar nerve.
I thought I developed it because of the stress on tissue between thumb and forefinger while riding on the hoods, but it is apparently due to pressure on the ulnar nerve via the heel of the hand, on the pinky side.
Others ever have this? Is it a bike fit issue? A Clydesdale/Athena issue?
Prevention seems the best remedy with good gloves and better handlebar padding (or a bike fitting). Thoughts on gloves?