I am covering a physical education class in an elementary school tomorrow and I am torn with what would be appropriate to wear.

Really, well track pants and a sweat shirt I think would be appropriate. I don't see this an issue.

Tick

I would personally wear a nice track suit with a golf shirt and gym shoes in good condition. Another option might be khaki pants with a golf shirt or sweater and gym shoes. I would avoid jeans, and would definitely wear light-soled gym shoes as some schools are very particular about their gym flooring and ban dark soled shoes or dress shoes from being worn on the floors.

Best if you can be active with the kids, but a collared shirt or a sweater, and long pants are more presentable in my opinion than jeans or shorts or a t-shirt.

So yoga pants and a v neck cotton shirt should be fine too then?