A growing body of evidence is telling us that exercise is one of the most important ways to prevent all sorts of chronic diseases. This list includes (but is not limited to) various cancers, diabetes, clinical depression, and osteoporosis.

Although we could just leave it at that, and say “exercise if you’re chronically ill,” we can take this evidence a little bit further: it tells us something very important about the relationship between exercise and the human body.

What chronic diseases mean for the body is that our systems aren’t resilient: the very same problem springs up again and again, and our body has los the capacity to change that. Because by exercising, we can reduce the risk for these diseases, this tells us something about the optimum state of the body: when we don’t exercise, our risk of chronic disease begins climbing. When we don’t exercise, our bodies stop being resilient. This means that the body’s resilient state is one in which it’s constantly exercising.

There is another growing body of evidence that suggests that cognitive flexibility and neurogenesis (the creation of neurons and neural pathways) increases during exercise. This means that, both physiologically and psychologically, exercise increases the body’s capacity to deal with new, novel, and unexpected stresses. Simply stated, exercise helps the brain and the body meet the demands of the world on the world’s own terms.

Thanks to this evidence, we can infer something about the body: if the human body and human mind’s resilient state corresponds to a state of constant activity and exercise, then the body isn’t meant to be passive, at rest, and unchallenged. The human body’s baseline state is one of exercise—one where it’s being constantly challenged physically, physiologically, and mentally.

In other words, the human body is an athletic machine.

This conclusion tells us something very interesting: the prototypical western, sedentary human doesn’t reflect the optimum state of the human body. And to snuff out a possible counterargument before it arises: we haven’t “evolved” out of the athletic roots that were so important in our early history and prehistory. Socially, we may be an entirely different animal (although many, myself included, would argue against that—we are as reactive, addictive, violent, aloof, and oppressive as ever). But physiologically and psychologically, we’re basically the same. If we had in fact evolved beyond those athletic roots, exercise would have no causal relationship whatsoever to chronic disease.

Which in turn opens up a very interesting line of inquiry: the pool of subjects used when we move new cures and treatment methods into human testing is highly skewed: we test these methods and cures on a population that, while ostensibly representative of the western, sedentary human, is not representative of the ideal—i.e. resilient—state of the human biological and psychological system.

What this basically does—and has done—is to get us into a mindset where prevention doesn’t exist, and cure is the only option. In systemic terms, prevention means increasing the resiliency of the system. Once that system is resilient beyond a certain threshold, there still may be some ailments that need curing. But when the prospect of increasing resilience is completely off the table—or worse, marketed as an “alternative,” and not as the necessary first step towards a solution—everything needs curing.