Mutants?

Has the human body changed? What has happened to us? How can Randy Couture, at 43 years of age, be the UFC Heavyweight Champion? Isn't 43 old? I know I thought it was when I was growing up but now it looks like 43 is PRIME! I remember when I was in 4th grade, my school was starting a new sports team...it was called Cross Country Running. I went to the first practice and my mom even joined me. We ran a mile!!! I remember the great feeling of accomplishment that I had from running a WHOLE mile. It was not something I had ever conceived of myself doing. Oh, and my mom did it too!!! That was amazing to me...my mom running a mile?!?!?!?! How could she do that? After all, she was old!!! She was my MOM and I had NEVER seen her run or do anything athletic! Well, I think that was the end of athletic endeavors for her unless you count chasing after my 4-year old nephew. Two years later, a friend and I entered and ran a 10K. What a feat that was! The school newspaper even wrote an article about it. That was 6.2 miles!!!!! Amazing!!!! Back then, a marathon seemed like it was a rare and impossible feat! Today, ANYONE can do a marathon. Triathalons are a dime-a-dozen. Eco-Challenge and Adventure Racing is even common. How far can we push the human body? Is it diet and nutrition? Is it science and technology? Of course technology has helped the progression of almost every sport. Everything from equipment to shoes to accessories to clothing and even food and recovery drinks. How have sports changed as a result of technology? Think of running, rock climbing, golf and tennis just to start. But I don't think it's just technology...I think it goes beyond that. Is it human self-perception?
As a kid, I remember seeing the Peking Acrobats (before it was changed to Beijing) on tv. They were amazing to watch. And martial arts films, those were amazing. Even watching Jackie Chan a few years ago...what he could do was such an amazing feat and a rarity. But now, do a video search on "free running" or "parkour" and you'll see amazing feats that many people are doing. Suddenly it seems like anyone can do it...and why not? Has the human body changed? Or what has changed that has allowed people to be able to push their bodies and their minds to these greater and greater extremes?