Sorry
@nemeth#5, but I cannot let that conclusion go unchallenged, at least as it pertains to golf. If you don't sweat when you play golf, you are riding in a cart.
If you walk 18 holes, you will perspire, even in mild temperatures. I think you said you grew up in Texas; if you can walk a course there in the summer and not sweat, you have ice water in your veins.
The average golf course, played from the men's tees, is a little over 4 miles long. Pros are playing tracks that probably average around 4.2 miles. But that is a measurement from the tee box to the flagstick, and doesn't include all the additional walking they do during the course of a round. A few years back I was curious about just how much actual walking I did in a round of golf, including walking from the green to the next tee box, walking from the tee to where my shot came to rest (frequently not in the fairway), surveying shots around the green, etc. I took GPS measurements over the course of about 6 or 7 rounds. The average distance walked, if I recall, totaled about 6.3 miles.
PGA professionals play courses that sometimes have a 5 minute walk from a green to the next tee box. When you include all the additional walking around they do over and above a recreational golfer, I have to think they are probably walking close to 7 miles in a round of golf, and possibly more.
A few years ago I read an interview that Boris Becker gave about playing golf. He had retired from tennis and was taking up golf seriously, including playing as an amateur in some tournaments. I remember he expressed surprise with how physically demanding playing 4 days of tournament golf and walking the course could be. He said he did not expect that. And I should think you will agree that Becker was a very fit dude when he was at the top of his tennis game.
Is playing 18 holes like running a marathon? No. But trust me, PGA professionals work up a sweat during the course of a round. Maybe they aren't dripping sweat, except in really hot and humid playing conditions, but they are perspiring. The average weekend Joe thinks golf isn't a physically demanding sport because when he plays he rides in a cart and tosses back a 6-pack or more during the round. But when you are talking about professional golfers, it is a different story entirely.