I bought these to help keep me warm so I can continue to run over the winter. I previously purchased the single layer version and they were great for the fall. As soon as it got colder, I had to upgrade to these. they do a great job of keeping you warm once you get running. My only gripe about these is that they seem to pill up a bit from the inside layer. It hasn't been a problem with friction or rubbing, but when I take them off after a run, pilled up fabric comes off and onto the floor. That won't stop me from using these very chance I get to run. I would buy again.