I aim a little on the cold side, because running a little bit cold is only uncomfortable and not generally hazardous and getting sweaty on cold days can be problematic as you can end up cold cold.

I try to have a zip up top so I can moderate the amount of wind cooling I get, and I will also take off my hat (and perhaps my gloves) if I start to get too hot.

I come from the cycling world, where the problem is a lot worse; I’ll be climbing hard up a 700’ hill at a slow speed and then riding descents at 35 mph. And the solution is to unzip on the way up the hill and just deal with the fact that you are going to be cold at times.

Zone 2 is easy. Extended is whatever your long run is.

“Careful about calories and health food choices” isn’t the way to lose weight for an athlete, despite what the majority of experts say.

Extended zone 2 training without much glucose around - fasted is ideal - is the ticket.

Running downhill is a technique thing - if you don’t have good technique it’s hard to run fast downhill without it really pounding on your legs/knees. If you have good technique, it can be a lot of fun to run fast down a hill.

It is relative, however; running down a 5% hill is fairly easy, a 10% hill is hard, and I can’t do anything steeper than that with any speed at all.