I've been experimenting running with my different layers while running to test breathability and managing my temperature. I've worn both fleeces and softshells while running in around 30 degree temps, and I felt they made me overheat and sweat somewhat during my runs.
So today I wore my Marmot Essence jacket, made of Marmot's proprietary fabric that is supposed to be almost breathable as eVent but is super light (< half pound). It was kinda windy and I definitely felt cold, yet I sweating a bit. Not as much as I would during summer, but definitely it was obvious I was working out. I guess I could have taken off my hat but I had headphones and sunglasses on so I didn't want to mess with those.
Is it unavoidable to sweat while doing high output activity even when it's cold?