Most times, classes do not interfere with training. As a student-athlete, you have priority class selection and your academic advisors make sure you do not have clashes. That is their job so it rarely happens. The only case of a ‘clash’ is in events where training may finish a little later and you might be rushed to get to class or the other way around. But it is never a big problem. This isn’t a big problem to worry about as the school makes sure that this is sorted before you arrive on campus.