It matters not whether it is NASCAR, golf, the NFL, NBA, motocross or whatever.
When you are speaking of the highest levels of professional competion they are all studs with skills beyond most people's comprehension.

Try to tell people how exhausting a full day of salmon/ steelhead fishing is.
All day, sun up to sundown, bucking fast water, cast after cast after cast.
Cramping up on the long drive home.
I've hit my bed in total exhaustion many times after one of those days but if you tried to tell an outsider, well, they'd laugh you out of the joint.