My kid has got themself picked for cross-country and is going to do some racing. They currently run in their trail trainers, which aren't up to much in sloppy mud, but they have plenty tech tees / tops / thermal sports jacket / waterproof sports shell / gloves / hats / waterproof socks etc. from their other sports and so far they feel equipped on the clothing front.
I and they know next to nothing about cross-country running.
What kit would a kid running at county level or thereabouts benefit from having? Would it be worth getting a pair of spikes? If so, what length of spike? Multiple lengths? How do they work out which length to use on a given day / course?
All help and advice appreciated.