As we develop new ways to explore and engage in extreme sports, it’s necessary to look back and see how far we’ve come from time to time.

What would our ancestors think of modern athletes, with their outrageous speed, strength and general fitness? Watching athletes compete at the top of their game is entertaining because what they do is not just unique, but incredibly difficult to boot. Between then and now, we have evolved tremendously in sport. It becomes even more impressive when we consider the gains that have been made in just the last hundred years.

Here are a few examples of just how far we’ve come and how much we’ve improved.

The Marathon

The modern marathon race stems from the myth that, after the Greek victory over the Persians at the Battle of Marathon, a soldier who fought in the battle ran all the way back to Athens to inform the people of the victory. Legend says that he arrived, shouted, “we won,” and died of exhaustion.

The first modern marathon was held in 1896 and was won by a Greek amateur, Spyridon Louis. It took him about three hours and he ran from the actual site of the battle of Marathon to Athens. Half way through the race Louis stopped in a village pub for a glass of refreshing wine. He then continued on to the stadium where the local crowd was so ecstatic that two princes ran the final lap with him and the king offered him any gift he desired.

Things have changed a lot. The current record for the men’s marathon stands 2:06:32. That’s right, an improvement of about a third. Now, the victor of the first Marathon ever wouldn’t even make the qualifiers for modern races. Fauja Singh, the oldest marathon runner ever, raced his last marathon ever this year at age 101, and Ultra Marathon Man Dean Karnazes is said to be able to run at a seven to ten-minute per mile pace forever.

Where did this big improvement come from? Modern sports science has taught us more about the human body and how to maximize its potential. Modern nutrition means that we grow up with the potential to be healthier, stronger and taller than any previous generation. Additionally, the fact that you can make a living being a professional athlete now (Spyridon Louis was a water carrier) means more time to train.

The 4-minute mile

The four-minute mile use to be considered impossible. Now, it is routine for top runners and has even been accomplished by several high school students in the US. It is has become so common that even some runners over 40 have made the mark. Runner, Daniel Komen, even made two miles in under 8 minutes. The current mile record is held by Hicham El Guerrouj of Morocco, at 3:43.13.

All of this was once thought impossible. In 1945, Gunder Hagg of Sweden set the world record at just one second over 4 minutes. It took another 9 years for someone to beat that, and that man was Roger Bannister, an Oxford medical student. Check out Bannister in the amazing footage above. It’s no accident that this magic barrier was broken by a medical student. Not only did he train hard, he used his scientific knowledge to do experiments and learn more about the mechanics of running. He optimized his nutrition and methods with science and managed to break the 4 minute mark for the first time. Once this knowledge was out in the open, it didn’t take long for that record to be broken. In the half century since, the record has gone down by 17 seconds. This isn’t quite as dramatic as the marathon, but it’s in a much shorter event.

Again, how did we arrive at such super human speeds? The answer, as the medical student who broke the record realized, is science. From those innovations emerged the fields of sport science and sport medicine. This research has driven gains through the athletic world. What use to be impossible is now routine.

Rock climbing

There are many examples here, but perhaps the most iconic is El Capitan in Yosemite. In yet another example of naysayers consistently being proved wrong, people use to say it was impossible to climb El Capitan. The very first summit of the mountain took 47 days. It involved lots of assisted climbing, drilling into the rock, placing expansion bolts and slowly making progress. Today, competent climbers can do it in 5 days.

The really astounding accomplishments have been made by professional climbers who free solo various routes in under a day, often in a few hours. From 47 days to a few hours, that’s a tremendous improvement. Every few weeks it seems an Adrenalist has broken a new record or finished an impossible climbing feat. Recently, Adam Ondra became the first climber to conquer La Dura Dura, and the treacherous Laila Peak was scaled for the first time in winter.

Everest without Oxygen

In 1953, Edmund Hillary and Tenzing Norgay became the first people to successfully climb the tallest mountain on earth. This was an amazing accomplishment, and it shows you just how far we’ve come. It wasn’t until 1953 that humans had succeeded in making it to such places. One of the big aids to this climbing team were routes and trails established by the previous climbers, not to mention the caches of oxygen left behind. Relying on these leftover caches seemed like the only way to make it to the top of Everest and through the so called “death zone,” an area where there is only 1/3 as much oxygen as at sea level. With such little oxygen in the blood, it’s possible to become exhausted just from breathing. Low oxygen results in a decline in mental ability, making it difficult to think clearly and make the split-second decisions necessary at the top of the world. It takes weeks to acclimatize, and it used to be thought that making the summit was only possible with the help of bottled oxygen.

25 years after the first summit, however, Reinhold Messner made the ascent with no oxygen assistance. When critics claimed he’d snuck oxygen he proved them wrong by summiting solo and with no oxygen on the harder route. From there it became routine for elite climbers to do the climb without oxygen. It only took 25 years from the first successful assent for an Adrenalist to climb Everest alone with no oxygen. That’s the essence of human beings pushing the limits of what’s possible.

Flight

For most of history we have been firmly stuck to the ground, only dreaming of flight. In 1903, the Wright brothers invented mechanical flight, but it still wasn’t enough for those most intrepid adventurers. Adrenalists wanted to fly on their own. Very soon after, men began to jump out of those flying machines. Thus began the evolution of the parachute, from the old canopy style to the modern paragliding designs. Today, you can sore like a bird in a hang glider or a paraglider. That, by itself, is impressive, but that still wasn’t enough for modern adventurers, however, as they didn’t want a machine, a canopy or a glider to aid them. They wanted to fly with their own bodies. Finally, the wingsuit was born.

These suits add lift with webbing between the legs and under the arms allow people to achieve a gliding efficiency of up to 2.5. That means, that for every foot you fall, you move forward 2.5 feet.

One of the most popular manifestations of this technology is proximity flying, which involves BASE jumping with a wingsuit, then flying close to the cliff edge and flying through waterfalls, rock arches and hitting targets. This sport continues to grow and be explored. It’s as close as a human being can get to flying without a machine.

It is, however, still extremely dangerous. In 2011 alone, 10 people were mortally wounded in wingsuit accidents. That hasn’t stopped Adrenalists from continuing to do it, because it’s the ultimate thrill. Just check out Jokke Sommer soaring through skyscrapers in Rio or Alexander Polli’s wingsuit target strike.

Wingsuiting is one of the ultimate examples of how far human abilities have been pushed. 60 years ago, the dream of running a marathon in 2 hours or a mile in under 4 minutes, climbing Everest with or without oxygen, or of flying through the air like a bird, were just that: dreams. During that time science, technology, training and sheer will have brought human abilities to the edges of the world. Imagine what we’ll do in the next 60 years.