Practice 2 things at the same time?!!
I have been a skateboarder and a guitarist for 45 years (I am 58 and started both at 13. still do both every day). It works for me, although I will admit skating has caused quite a bit of bodily destruction. every limb is now dislocatable!)
Incredible. I practice guitar and piano most days. I like outdoor adventures too, but skateboarding would have me worried. One serious fall and it could put playing music on hold. Skiing is good. At least when I fall I land on snow. As I get older I like falling less and less.