I might not be the right guy to respond, as my ride is alot shorter than yours and I see utilitarian bicycling as something different. Specifically, I'm not in it to win it, I'm just riding my bike to work.

This is my 3rd week of commuting 3 mi. each way to work. I've never felt so loose. Prior to this my back felt tight every morning. Now I simply stretch it in the heat of the shower and I'm good to go.

Staying away from coffee is not going to happen, so I bought a thermos which my local Starbucks barista is happy to fill and which I greedily suck down at my desk.

I guess if I was riding 24.50 miles each day I'd think about training too, but as it is I'm just having fun!