<p>If by olympiads you’re talking about the qualifying exams for IChO/IPhO/IBO/IMO, it shouldn’t be too difficult to get your school on board as the time commitment is very very very low. I don’t know how it works in the US, but where I’m from, the teachers only needed to supervise one 2 hour exam (and only one teacher in the entire school was needed). Beyond that initial level, the exams were administered by a national authority.</p>