Super comfy men's practice pants?

I'm looking for suggestions for men's pants. My Legs can be painful so I'm looking for something ultra lightweight. Loose, not tight. I need something that is going to be as comfortable as possible to move in during yoga. These do not have to be "Yoga" pants. Anything that someone knows about is a great suggestion. I've looked around a lot but haven't been able to find too much. Thank you.

I wear long (just over the kneecaps) cotton cargo shorts that are very thin material with a tie waist (no belt). The store I buys clothes doesn't always carry the same gear so now I'm out of luck to buy more.