Bad analogy there, my friend.
BTW, DeanKarnazes is one of my friends from windsurf racing. Just 10 years ago, he was number one in those century runs thru the deserts.
We cannot physically run 100 miles. I can't run 6 miles in a whole day.
But standing on the court, I can easily play 10 doubles sets, albeit at 2/3 of my speed (
Couple years ago, I'd play maybe 7 doubles sets, 4.0 level, then drive down to the beach and windsurf for 2 hours, a full session for even the established pro level windsurfers. Figure I can skip the windsurfing, and play 4 more sets anyday.
Have you ever tried windsurfing? It's not standing around taking one step back and forth.