How long is a "short" ride?

[KnottedYet]

I've been riding regularly for 2 years now. However, I still haven't been able to get in the "training" mode. My typical ride currently is between 20-25 miles and I ride 3 to 5 times a week...which is about to change because of the shorter days. I try to push myself but haven't done intervals or hill repeats per se. I've read about people doing "short" training rides where they do intervals. So, typically, how long (mileage and/or time) is a "short training ride" vs. a "long recovery ride" for someone new to training who does my general distance?

Aren't you still dealing with lung issues? It might be best to stay out of "training mode" and not push yourself until the goober in your lung is removed, do fun rides instead for now?