What Is The Most Physically Demanding Sport In The World?

100% Motocross.   That sport is crazy on the physical scale.   Studies show a constant heart-rate of 190 bps from start to finish (about 40 min).   No other sport comes even close.   It is also regarded as the most dangerous.   That must be why the heart rates are so high.

Motocross, hands down. I've played sports such as hockey, cross country, soccer and lacrosse, and motocross is by far the most tiring sport I've ever participated in.

Motocross for sure

Motocross

Motocross. I have played like about every sport and motocross is by far the hardest. If you don't think so then get a dirtbike and go ride a 30 minute moto as fast as you can

Motocross, it is not only incredibly physically demanding but mentally as well. I have played many sports and by far motocross surpasses all of them. After a small 10 - 15 minute moto every muscle is worked to its max

Motocross on a ATV, is even more demanding than on a bike. A lot more g-forces in the corners than a bike and a extra 2 wheels to beat you with. And for the guy that said gymnastics, if a motocross racer practice that much he would be dead at 8 years old.

Gymnastics. The pro's  have to practice 7 or 8 hours per day. You need to do over-splits and have muscle pretty much every where on your body. And you need to start at about 5o6 years old at the oldest, which is when you start doing handstands and cartwheels on the balance beam. You have to work out, stretch, and finally do the sport. It is very demanding both mentally and phisically. I dare you to look up gymnastics training on YouTube. Gymnastics is the most phisically demanding sport in the world!!!

Boxing

A marathon or triathlon, are both very demanding.

Rugby, you run about 8 miles per match+hit as hard as football+no breaks+scrums are the most physically demanding thing I've ever experienced.

Ballet!
Takes lots of muscles, responsibility, self control, and it is a lot harder than you think!!!! You need muscle everywhere and a lot of practice and skill