Yes it depends! If you have a hot horse... or a horse that gets very stiff then I'd do that but don't work them too heavily but yes I believe it'd be a good idea. I would flat two hours before then get on about 30 ish mins before I need to be in the ring quickly flat them for maybe a few minutes... clear a few jumps and then go into the ring. You don't need to over work them, or school then like you would at home, just make sure they're supple, loose and listening to your aids. Hope this helps... good luck!! (You must be quite good if you're At international level)😂
Depends on if ur horse gets tired really fast. Probably just warm her/him up lightly before u go in to do ur course.