What Doesn't Kill Us: How Freezing Water, Extreme Altitude, and Environmental Conditioning Will Renew Our Lost Evolutionary Strength

by Scott Carney

With no challenge to overcome, frontier to press, or threat to flee from, the humans of this millennium are overstuffed, overheated, and understimulated.

The developed world—and, for that matter, much of the developing world—no longer suffers from diseases of deficiency. Instead we get the diseases of excess.

There is a growing consensus among many scientists and athletes that humans were not built for eternal and effortless homeostasis. Evolution made us seek comfort because comfort was never the norm. Human biology needs stress—not the sort of stress that damages muscle, gets us eaten by a bear, or degrades our physiques—but the sort of environmental and physical oscillations that invigorates our nervous systems. We’ve been honed over millennia to adapt to an ever-changing environment. Those fluctuations are ingrained in our physiology in countless ways that are, for the most part, unconnected to our conscious minds.

For a person not regularly conditioned to temperature shifts, vasoconstriction is painful. The only way that most of us can trigger the muscle response is to actually go outside and feel the cold.

Weak circulatory muscles are a side effect of living in a very narrow band of temperature variation. The vast majority of humanity today—the entire population that spends the bulk of its time indoors and/or whose only experience when it gets too cold or too hot is wearing state-of-the-art outdoor gear—never exercises this critical system of their body. Even people who appear physically fit, with lean muscles and chiseled abs, might be secretly hiding weak circulatory muscles. And the stakes are huge: In the long run, circulatory diseases contribute to almost 30 percent of the world’s mortality.

Despite all of our technology, our bodies are just not ready for a world so completely tamed by our desire for comfort. Without stimulation, the responses that were designed to fight environmental challenges don’t always lie dormant. Sometimes they turn inward and wreak havoc on our insides. An entire field of medical research on autoimmune diseases suggests they originate from fundamental disconnect between the outside world and an understimulated biology.

Richard Wrangham, a biological anthropologist at Harvard, argues that the human jaw started shrinking once we learned how to control fire. Since cooking softens meat and kills potentially harmful bacteria, we no longer needed the pronounced mouths and powerful forward-jutting jaws of our more apelike ancestors. Cooking also made vegetables and meat more nutritious. Instead of spending most of our time chewing plant fibers to break down resilient cellulose we could outsource that effort to fire, which radically increased our ability to extract calories. Wrangham writes in his book Catching Fire that the invention of cooking by our early ancestors was literally what made us human and sparked the evolution of Homo erectus 1.8 million years ago. Homo erectus was different than the great apes that preceded it. Homo erectus walked upright on two feet, and, because digestion takes less time when food is cooked, has a smaller gut than most apes. Over the next million years or so Homo erectus experienced a gentle progression into the more refined human form we now enjoy. Presumably because Homo erectus didn’t have to spend so much time chewing, it could do other things that led to evolutionary pressure that increased reliance on technical skill; therefore, brain size increased. At some point, Homo erectus also lost its body hair, seemingly because he could use fire to keep himself warm at night.

he believes that there will always be a moment when he will have a semblance of control again. The trick is waiting for it to happen.

The Zen during the tumble is humbling and can tick by for breathless minutes. Hamilton’s lungs might burn and his body might be brutalized by the swirl around him. “But at some point,” he says, “if you make it far enough, the grip will loosen. You have to keep your mind still while you are in the midst of it all, knowing that your chance will come.” And when it does let up, Hamilton taps into all of the stored up energy in his body to make his move. That’s when he lets the fight-or-flight response take over. He uncoils like a jack-in-the-box and sprints with every shard of energy in his body to reach back toward life.

The four rules to his formula—commitment, crash, submission, and escape—provide a blueprint for every failure in his life, he says. It has allowed him to survive the unsurvivable and has given him a guiding philosophy for every venture he gets into outside of the water. “It’s the attitude I go into before I start a new business, or a new training regimen,” he says.

“Yes, they know fight and flight. The wolf chases them and they die. But everything dies one day. It is just that in our case we aren’t eaten by wolves. Instead, without predators, we’re being eaten by cancer, by diabetes, and our own immune systems. There’s no wolf to run from, so our bodies eat themselves.” This is, of course, at the core of Wim’s philosophy. Without something to fight against, the body will fight itself.

the entire human race has been conditioned to think that the outdoors is dangerous. Or that working out in the cold is lunacy. But guess what? This is something that people have been doing for hundreds of thousands of years. We were made for it.”

humans are not just bodies bounded by the barrier of their skin; we are part of the environment that we inhabit.

biological relationship between life and its environment is the most ancient transfer of knowledge that any human can ever experience. It’s so ingrained in our very beings that the language of evolutionary programming isn’t a thought, it’s a feeling: a shiver, a rush of blood, or a quickening of the senses. Just a hundred years ago most of us knew the language of shivering. A thousand years before that our bodies tracked with the seasons. Ten thousand or more years before that our species migrated between continents on rafts of seaweed and surmounted mountains in little more than animal skins and leather soles. Those ancestors probably didn’t think of themselves as different from the environment at all. They knew what we are learning again today. That we are all just here. Surviving. Together.