I picked up trail running after developing a general malaise for MTB a few summers ago. My sister and Bro in-laws had been doing marathons. So I figured trail run was a good thing to try. That was about 3 years ago. I have kept it up and I really like the sport alot. I can run 10 miles in a couple of hours if I want to wear myself out and I think its more of a concentrated workout that fits into my busy summer schedule.
I found that it had a great impact on my skiing. I think the extension movements from trail running more directly apply to skiing than cycling movements. My foot quickness is alot better, my ability to feel the bottoms of my feet is more sensitive, that leads to much better balance, and I feel like the supporting muscles in the lower leg are much stronger and I am able to stand on my skis independently of my boots now where as before I was often leaning on my boots to support me. Often when I want to ski down a challenging slope I will tell myself to run down that hill. It feels like a direct translation to me.
I found that it had a great impact on my skiing. I think the extension movements from trail running more directly apply to skiing than cycling movements. My foot quickness is alot better, my ability to feel the bottoms of my feet is more sensitive, that leads to much better balance, and I feel like the supporting muscles in the lower leg are much stronger and I am able to stand on my skis independently of my boots now where as before I was often leaning on my boots to support me. Often when I want to ski down a challenging slope I will tell myself to run down that hill. It feels like a direct translation to me.