Wondering what folks who run ultras or run many miles often think about the need to replenish glycogen.  Most of my miles are aerobic in nature.

i would assume my body is much more efficient at using fat for fuel and hypothesize I use less glycogen.  I know I've read articles that indicate your body relies primarily on glycogen for fuel the first 60-90 minutes of running.  But wonder if that applies to those who run medium to long distances for most training runs?  

Asking as I would prefer to replenish with less post-run sugar if not really needed.  That and I am day-dreaming in a meeting.