A man can overwork his dog by having it work 5 or 6 days in a row without any significant rest period. Overworking a dog is corrected by rest. It's not corrected by allowing a dog to recover while working. Your dog isn't going to be allowed a chance to recover while in a show as his opponent isn't going to allow that to happen. The animal has plenty of time to recover once the work is over for the day.