Having a lot of friends in England, I always get into a debate with them about rugby vs football. Their claim is that rugby is of course the sport with tougher men, because they don't play with pads. To which I always reply "Do you know why they use pads in Football? Because if they didn't, people would start dying! Would you enjoy being blindsided by Nadamukong Suh without pads(Which Sports Science proved had the impact of a 35 mph car crash)?" That argument always goes on for a while, and then we get into an even more heated debate about which sport has the better athletes. I've always, and will always say that American Football players are the greatest athletes on Earth. To piss them off further, I'd semi jokingly say "Give me a team of even College Football all stars, and give them 3 months to learn Rugby, and they could probably give the best Rugby team a hell of a game". Nothing would really piss them off more than that.
This point is always harder to prove to them, and the debate is endless and pointless. No disrespect to rugby players, they are indeed great athletes, and the game of rugby is difficult to play. But American Football, when it comes to size, speed, and overall athleticism, is un matched by any sport on the planet.