I already have short muscles and i need to keep them long for ballet.What excersises should i do on a daily basis to keep them long and make them longer?

I am a 15 year old male and i plan on joing my highschool ski team. I have been skiing for quite some time but never too seriously. I was wondering what exercises or routines i can do to get myself in shape and work skiing muscles before i have to try out for the ski team?

Lets say your in relatively good shape but you want to boost your exercises up a notch to prepare it for an intense ski trip. What type of cardiovascular/ weight exercises should you do to prepare your body and especially the muscles you use to turn you body and to make ski jumps, paying particular attention to the muscles you use to ski so that you don’t feel pain after skiing from not using those muscles.

I’m going on a two day skiing trip in a week. I haven’t been skiing in years and do remember it was pretty physically demanding. I am in pretty good shape, work out probably 4-5 days a week, but is there anything I can specifically do to prepare for the trip? Certain muscles or exercises?