Actually, I'm not. We definitely had outcome-based (not effort-based) grading for both physical and mental disciplines in my school.
Oh and in primary school, teachers would go in the teachers lounge to smoke while they were given a break by us being in PE.
For PE we had normatives we were supposed to meet -- so many pullups, etc (based on old soviet army normatives I think :)), and if you don't you got corresponding grade.
I would make sense to break PE course into two -- one about theory and one about skill and have two separate grades for them.