my calories are naturally lower on rest days most of the time....I also give myself rest days as needed, usually on weekends when my routine is different...keeps me from getting bored, injured or burned out
however I DO have days where I just DO NOT want to run and I bargain with myself like "do half of it" or "just do the running warm up part" and then give myself permission if I truly feel too tired or like I need to stop, that I will stop running and just walk out the rest of the 45 minutes on the treadmill
that's only happened once or twice that I can remember....once I had full intentions of doing a running workout on the treadmill and started to run and my whole mind and body just said "NOOOOO" and I just stopped and walked....I don't even know why, but I believe in listening to your body and when my body said that loudly that day "NO" I listened...and that never happened again
the only other time I quit in the middle of a workout was when I was running and really struggling to breathe....turns out I had pneumonia but that's another story