You beat me to that response. I still have that same singlet from Skinny Ravens BTW. I haven't seen her at the races in years, but finally did at a half I won last spring in Anchorage. I have spent my life only knowing cold climates livingmostly in Russia and Alaska. I trained outside on both sides of the pond down to -56. I only trained indoors for 1-2 speed workouts a week at a top facility in Moscow December -early April. Even in my buildup for Worlds and Euros ( I run the 50 and 100k), I still did those long runs out in the snow. Mid 2015-mid 2017 I spent 8 months a yr training in the mountains in Alaska. I am a mountain, ultra, and trail runner primarily. My legs got even stronger, but even in the crappiest of winter weather, I ran outside. Snow and snowshoe training makes one strong too! This led to some nice wins at mountain and trail stuff on both sides of the pond. Well, life and work took me further out a year and a half ago to the tundra. It was a royal pain in the a$$, and not cheap, but I invested in a treadmill and had it shipped out. I did not want to lose my mountain legs. I have a treadmill that does ascent and descent . Both muscle groups need to be trained. keep in mind, I had never set foot on a treadmill, but figured this was the only solution since the tundra is damn flat. I can see the mountains from where I am, but they are 15 min by small plane from here. I combine indoor and outdoor workouts.Twice a week, I do a run outside then come in and do a sustained climb. The climbs gradually increase closer to my mountain races and I add more descent as well. Long runs for the sake of my sanity are done outside regardless of temperature. Speed is done generally outside, but if it's super icy ( I have trained in Icebugs nearly 20 years)or sh!tty, I'll do the speed indoors to get the right paces much like I did on the track in Moscow 1-2 times a week. Recovery days /easy distance is outside on the tundra sometimes I snowshoe on the trails. I train in these conditions 8 -9months a yr. Last spring, I returned to my favorite mountain race. After nearly a year since I'd transferred to the tundra and had to incorporate treadmill training, to my surprise not only did I win again , but I cut nearly 5 min from my 20k time. It's a 10k up 10k down course on dirt and rocks. I was glad to know my investment had paid off. I did just as well at mountain and trail stuff back in Europe shortly after. The treadmill had worked.