I did my commute in 45 minutes. Still averaging under 10mph. I don't many times go over 12mph and I'm ragged climbing hills (still thinking about dropping the chain rings to 26-38-48 instead of 30-42-52).
This used to be a 1 hour commute. If I can sustain 18mph with climbs around 10mph I should be able to manage it in half an hour.... maybe less.
My heart's still not taking it well; I'm running myself out to the end and then further, pounding hard and fast in my chest, gasping for air, and still going. My legs seem to be able to take it way better than they used to.
I'm getting faster, but it's not getting easier ...