This subject is exciting for me, but I'm trying to figure out if I have anything to add of additional value. I run super steep trails every day. They are about two feet wide and completely littered with small and large rocks that I basically consider to be ball bearings most of the year unless it's rained (very infrequent). Usually do about 1500 ft vertical. I almost always run with poles. I use the poles mostly on the way up. I get kinda bored after all these years just running with my legs. On the ascent, almost always plant the poles simultaneously to push, except for downward jump turns. Having the poles held parallel to the ground on the descent is interesting. My jumping is much smoother, perhaps like having outriggers. I even use 3 pound weights on my wrists with the poles. This creates a quiet upper body. I'm not going for speed, but rather how to kick my own ass. My brother labels this aerobic junky. One thing this hazard running does is to constantly make me aware of how important tactics are. For example, when going down really steep slippery ball bearing segments, I lean waaay forward from the hips. It's remarkable to me what I can run down with that. I find that when inevitable slips occur, my body just takes it in stride with the proper balance. This teaches me a lot about skiing, which I think about all the time while running. Also, the dangers are right there, keeping me very focused. Even then, stuff happens. Dislocated fingers. Then once I fell downhill onto a one inch diameter stump, right on my heart. This was the same year a beloved local at Taos died in the Whats chutes the same way. Thought about him as I got up, wondering if I was okay. Did a ski week with his sister-in-law last February. I digress. The trail is so curvy and lined with the chaparral that I can't look far ahead, and the rock situation is such that I have to make very quick decisions for each step. It gets very interesting when I'm fatigued. Then I find that I must be deliberate and push myself to be aware at all times. It's all excellent mental/spiritual/physical conditioning for skiing. I'm very grateful to have mountains here. I'm not my best on flats, I just really like constantly changing challenges of running steeps. This all parallels the kind of terrain I love to ski. I would bore you all by writing more cuz I love thinking about this subject, but my wife says we must cut our dog Tilly's nails right now.