No matter how good shape any rider is in I really don't think it could physically be done. Figure each moto goes 35 minutes with about 15 minutes between to rehydrate, cool down, and rest. Even a super hero like Patman would drop over.;)
Super rat is correct. You cannot run two classes at a national event, you are eligible to run both classes at a SX. Don't ask me why, rules is rules.:think