Sherpas, an indigenous population native to the Himalayas, are widely known for their climbing prowess. They've been instrumental to the success and survival of many expeditions on Everest, K2, and others. They're seen as superhuman in the climbing community, performing incredible feats like making a 2000 meter (over 6,500 feet) descent in under two hours, something that took the rest of the witnessing team most of the day.
For a normal human being, altitude sickness is pretty extreme, even deadly. In fact, at above 3,000 meters in altitude, it's recommended that climbers ascend at most 500 meters per day. But Sherpas don't have that problem.
So how do they do it? Is it their diet or exercise? Maybe a special plant that gives them heightened abilities? Hell, did they just get Cap's serum?
The answer is actually much more simple-evolution. Denny Levett, a consultant at University Hospital Southampton in England, compared the physiology of Sherpas to those of other climbers. She found some extraordinary differences. Firstly, the mitochondria in their cells were far more efficient at processing oxygen, allowing them to live at high altitudes while functioning perfectly normally. Their blood flow also remains constant, despite high gains or drops in altitude.
All of this is because they've just been there. According to a 1994 study, their ancestors have lived there for over 600 years. They've adapted to the extreme climate admirably.
So, if you're looking for the secret to becoming a superhero, this may not be the way. But if you're patient, maybe your far distant descendants will be able to.