Photography might not be a sport. But don't underestimate the physical effort of running around with +5kg (if you have small lenses) in the blank sun on un-levelled terrain for an entire day. Ducking, crouching, running because you don't want to miss something, up on a hill to realize it's not even a good spot so you go down again after like 5 min.
Every year again the first few motocross races I start photographing I am having a stiff neck or back ache the day after.
But other then that I am surprised I didn't got an hearth attack yet or got weigh over 100kg's. Because since I quit athletics on the age of 13 I haven't done any (physical demanding) sports. I did some olympic shooting and snooker and stuff. Very difficult and underestimated sports, but not rly physical demanding enough to keep you in shape

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