“Cold” is kind of relative, but I trained the last week in 40-50 degrees in the garage as the in-laws were in town and I had to give up the pain cave. I did my ramp test in mid-40s, and I don’t know if it affected me. I didn’t feel warm until several steps in, where normally I can warm up pretty quickly indoors. Still, by the time it mattered, I was plenty warm.
That said, it might’ve had a cognitive effect, as I felt slow and had a tough time focusing. I attribute that more to my sleep being off with the newborn than anything. I don’t think it increased my RPE; I usually get that effect when I’m too warm, rather than too cold.
It definitely had an effect on my breathing as the colder (for here), dry air left me with a little cough the rest of the day. I don’t think it affected the test, but maybe.
When I was riding in the cold garage, I’d start with the fan off and some kind of t-shirt on, usually a long-sleeve tech T. Once warm, I’d start the fan (I have one of the remote controlled outlets) connecting the fan to the house power, and if that wasn’t enough I’d strip the shirt off as I do inside.
The rest of my garage rides were Endurance/Zone 2 rides as it was a recovery week, and I’ve been able to move back to the normal cave starting yesterday.