Golf actually is; it's approx 7k's or more of walking, swinging a club violently at least 60 times which uses a large number of muscles (the rest is putting and chipping - not much energy used in those shots) and pulling a buggy with a set of golf clubs on it, or carrying the golf bag....Golf is not.
Golf is not.
When I was a Trainee Golf Pro, my best friend and I played 72 holes - 4 different courses - in one day!!You obviously haven't played 36 holes in one day. Very demanding on the body. Know of a few golfers who are unable to play due to injury. One can't play because he puts his back and neck under that much pressure when he swings that he's doing damage, he's now a professional angler (yup catching big fish all day is alright for him, but not swinging a club)... Mind you he hits 300m+ He has driven every par 4 at the course I play at.