I've been to a few gyms and most of them have spring, summer, fall, and holiday breaks. And 90% of the time everyone has off. Although i was at one gym that had a break and during the weekend of the break the worlds teams came in (but had that week off)
I think giving the kids 2 practices off won't make or break your worlds performance. Give them Monday and Wed off... but that following sunday, 4 hour practice.
Everyone is happy after a break, whether it be athletes or employees.