The Incredible Human Body was Not Built for the Sedentary Lifestyle of the 21st Century
Whether you think so or not, your human body is an incredibly well-designed yet fragile machine. A biological wonder millions of years in the making. But there is an important message regarding your body in the 21st century that you need to keep ‘in mind.’ Everything you do physically, eat, think, and feel, and every emotion and experience changes your body and brain in ways not necessarily anticipated in the evolution of your human form.
The human body is awash in information. You have billions of cells, and each one is constantly signaling its neighbors with highly subtle chemical messages. Every piece of tissue has a rich network of nerve connections and hormonal receptors — and millions of their signals fly around your body all the time. The information traffic in your body dwarfs all the traffic on the Internet and all the phone calls worldwide.
And you mustn’t forget that the human body is made of meat, sinew and fat, and many other ingredients that break down over time and must be constantly renewed. The muscle cells in your thigh are entirely replaced about every four months. Your blood cells are replaced every three months, your platelets every ten days, and your bones every ten years. Your taste buds are replaced daily.
The human body was not designed for modern life
The human body evolved to be perfect for its natural purposes. But it was not designed for modern life with its fast food, TV, and sedentary retirement. Our bodies were designed for life in nature, where only the fittest survived. Most of our body parts have as much business in a shopping mall as a woolly mammoth.
Left to our own devices, our bodies and brains will consistently, and without fail, misinterpret the signals of the 21st century. Research confirms that inactivity is a looming factor in at least twenty of the most chronic disorders of human beings.
Yes, the list includes obesity, but it extends far beyond to other afflictions of civilization, including congestive heart failure, coronary artery disease, angina and myocardial infarction, hypertension, stroke, type 2 diabetes, dyslipidemia, gallstones, breast cancer, colon cancer, prostate cancer, pancreatic cancer, asthma, chronic obstructive pulmonary disease, immune dysfunction, osteoarthritis, rheumatoid arthritis, osteoporosis, and a range of neurological dysfunctions.
In addition, a sedentary lifestyle is associated with lower cognitive skills. To be blunter, our inactivity is making us dumber. Cognitive impairment is not so much a consequence of aging as it is a consequence of our sedentary lifestyles.
In short, we have adopted a lifestyle which — for humans designed as we were intended — is nothing less than a disease. Think about that. Our lifestyle — especially in retirement, especially in our highly automated society — is a disease more deadly than cancer, war, or plague. We live longer because of modern medicine. But many of us live wretchedly — and many of us die much younger than we should because of our modern lifestyle.
How the human body becomes frail
You don’t have to be in your 70s or 80s to be heading down the path to frailty. Age doesn’t necessarily matter. According to a recent study, nearly half of people in their forties show as many symptoms that could lead to frailty as people in their seventies.
Frailty describes the condition of becoming weaker and more delicate. Frailty incorporates a decline in general health, energy levels, and cognition. This can eventually lead to increased susceptibility to further illness and hospital admissions.
Pre-frailty is defined as the risk of frailty in later life. Signs of pre-frailty include poor lower limb strength, poor balance, poor foot sensation, being underweight, pelvic problems, and poor nutrition. Research suggests that pre-frailty could be prevented by increasing physical aerobic activity, building muscle, improving exercise tolerance, better nutrition, and improved mental health.
Experts say it is not too late for people in their 40s or even younger to avoid poor health and frailty in older age. They encourage people to take matters into their own hands and shun their bad habits, such as physical inactivity, bad posture, and mental stagnation.
We may be a sedentary culture, but while we’ve been couch-bound in front of TV screens and computer monitors, science has been busy collecting a massive pile of evidence that says the quickest, surest path to the health and well-being of the brain and body is aerobic exercise and muscle development. More about these activities in my upcoming articles on exercise.
The process of growth and decay
Aging is a complicated form of entropy. Each of us is caught between two forces that contend for the future of our physical and mental well-being: growth and decay. Most of what we call aging, and most of what we dread about getting older, is decay. That is critically important because we are stuck with aging, but decay is an optional part of that process.
Every person can choose which side to favor — growth or decay. Decay isn’t destiny. There is no reason you can’t decide to select growth every day. Nature balances growth with decay by setting your body with an innate tendency toward decay. The signals are not powerful. But they are continuous. They never stop. And they get a little stronger each year.
In our forties and fifties, our bodies switch into a “default to decay” mode, and the free ride of youth is over. In the absence of signals to grow, your body and brain decay, and you “age.” We can override those default signals and change decay back into growth with surprising ease.
So how do we keep ourselves from decaying? By changing the signals that we send to our bodies. The keys to overriding the decay code are daily exercise, emotional commitment, reasonable nutrition, and a genuine engagement with living. But it starts with exercise.
Being sedentary is the most critical signal for decay. Your body watches what you do (your physical activity and behavior) every day. In nature, there is no reason to be sedentary except for lack of food. But in today’s world, decay comes from turning on the TV when the sun is out. From cracking that beer while you watch. From every trip to a fast-food place to get a supersize order of fries or a soft drink full of sugar and caffeine. From riding (instead of walking) around the golf course in a golf cart. From sitting home alone feeling obsolete and irrelevant.
Decay comes from giving up on life and failing to engage. But decay can be stopped — or radically slowed. Aging is up to nature, but decay is up to you. And this all starts in a heartbeat because the decay signals get sent continuously — no matter what you do. Your body tissues and neural circuits are always trying to decay. Muscle, bone, brain: always trying to melt like ice blocks in the hot sun.
The good news is that the decay signals may be constant, but they are weak. If you don’t send any signals to grow, decay will win. But even a modest signal to grow will work. A decent workout or even a good, healthy walk will drown out the ‘decay’ noise. This is the point: you need to do something every day. It isn’t complicated, but you have to be committed to some form of ‘growth’ every day.
