Everything you read that seeks to give advice to our demographic bulge known as the Baby Boomers, tells you to avoid the sedentary life at all costs. A sedentary lifestyle is thought to be remarkably harmful to human health and is considered one of the most significant preventable health risks in modern society. There is an evolutionary mismatch between being sedentary and good health. We’re built for movement. Humans evolved as hunter-gatherers, walking 5-10+ miles daily. Our bodies expect regular physical activity. Sitting all day is historically unprecedented and yet, over the last 100-150 years the sedentary life has become both possible for the masses, and, some would say, more necessary based on where productivity tends to reside in the information/communications era. It’s hard to say whether that will change with the onrush of AI into our human equation. There is an argument that says that manual labor will be least impacted by AI. Let’s face it, replicating the complexities of the human body is far tougher with physical robotics that it is to replicate huge amounts of the human mind and its cognitive ability through digital architecture.
Modern sedentary life conflicts with millions of years of evolution, causing cascading physiological problems. It all begins with the cardiovascular system. Blood flow slows when sedentary, increasing clot risk. HDL (good cholesterol) decreases. Blood pressure rises. Arterial function deteriorates, and eventually, the heart muscle weakens. Contrary to the logic of mechanics as we tend to know it, the heart doesn’t wear out from use. In fact, the opposite is true. Unlike mechanical devices that wear out with use, the heart gets stronger with appropriate exercise and weaker without it. This seems backwards, but it’s fundamental to how biological systems work. Heart cells constantly repair and maintain themselves. One of the strengths of the human system is that unlike a machine part, cells regenerate components. The average human pulse rate is 70, which means that the average human heart beats 100,000 times per day. Imagine that. If we say that the average human lifespan is 80 years, that translates into about 3 billion heartbeats in a lifetime. They say that the human heart is designed by evolution for this workload and that the cardiac muscle is both remarkably durable and that efficient energy use by the heart minimizes any cellular damage from use. An exercised heart does less work overall because it’s more efficient. Fewer beats are needed to pump the same amount of blood.
The only medications that I take are for my blood pressure. The constantly evolving cocktail of 5 meds are intended to get my blood pressure to the optimal 115/75 range with a resting pulse rate of 60 beats per minute. My systolic pressure is the challenge, but I have asked the question of what it means when systolic pressure is a bit high (135), diastolic pressure is low (65-70) and pulse rate is quite a bit lower than normal (50 resting). The most common cause of that configuration is said to be medication. AHA! The cure may be the culprit. But the other possibilities are also worth examining. As background, 23 & Me told me years ago that my DNA telltales show that I have a genetic predisposition to being a performance athlete. Once you stop laughing, as my family always does, understand that my resting pulse rate was always low, even before meds, so there may be something to this. Despite what I might try to tell you about how well I skied or played squash back in the day, I am unlikely to be mistaken on the street as a performance athlete. I also spent a month when I was 45 at Duke University in their weight loss program. They spent that month testing me every which way and could find absolutely no problems with any of my systems…much to their great frustration. I also regularly get Lifeline Screenings that measure things like arterial conditions and keep coming up clean with both relatively plaque-free arteries (cardiac, carotid and peripheral) and quite flexible ones as well. My recent spate with edema (now solved) caused me to get venous and arterial sufficency exams on my legs and I passed with flying colors.
I review all of that because the next explanation of my BP/Pulse numbers is that I am a fit individual with stiff arteries…yet that doesn’t seem to be the case. Perhaps it is the next item on the list….aortic valve regurgitation…but my recent echocardiogram tells me otherwise. By the way, the echo also did not show any enlargement of the heart, which is surprising in someone of my size and age and is another indicator of a healthy heart. Then perhaps it is that I have an athletic heart with genetic early arterial disease…but neither of those characteristics is really true for me. I have no thyroid issues, so what’s left. Well, according to various AI-generated possibilities, I am down to only one. And that is that my numbers are the result of a normal aging process, helped by some meds and generally good fitness. This fits for people who are older and stay reasonably active. As I have suspected all along, my naturally low pulse is protective rather than threatening. It can’t fully prevent vascular aging, but perhaps it is allowing my heart to regulate itself for the long haul to the benefit of my longevity.
Trying to figure out the complex equation of holistic health is very challenging and while I completely understand the value in giving simple prescriptives to the general population, it may be wrong to say that being sedentary is all bad. Rest is deemed critically important for good health in aging, and it becomes arguably more important, not less, as we get older. It’s one of the most under-appreciated factors in healthy aging. Recovery becomes the limiting factor with age. Young bodies recover quickly from stress while aging bodies take longer to repair and restore. The balance between stress and recovery determines health outcomes. Tthe old adage, “Train hard, recover harder” becomes essential. Sleep is the foundation of rest. It is important to cellular repair. I feel that every day I spend heavy lifting in the garden. The aging sleep challenge is that sleep architecture deteriorates over time as we get older. We get less deep sleep (Stage 3/4), more nighttime awakenings, earlier wake times, lighter sleep overall and decreasing REM sleep. I see all of that in my sleep patterns. I solved the biggest of those problems by starting with my CPAP 32 years ago. I am never without it. But there is still what I would call mild muscular pain from lying prone too long. By 6:30am I mostly HAVE to get up, just to change positions. So maybe the sitting to read, write and watch TV make up for that missing nighttime rest. I like to think so.
They say that “Sitting is the New Smoking”, but that seems somewhat hyperbolic to me. I understand all the insidious aspects of the sedentary life. It’s effects accumulate gradually. There is no immediate pain or consequence to it. The damage it may bring is invisible until its significant, and reversing its impact takes lots of time and effort. This self-reinforcing process of Inactivity → weight gain → harder to move → more inactivity → muscle loss → weakness → less activity → more muscle loss → poor mood → less motivation → less activity → worse mood, is all pretty pernicious. But our modern life pushes sedentary behavior and still we are all living longer…go figure!? They say we need at a minimum, 150 minutes of moderate activity weekly (30 min, 5 days) or 75 minutes vigorous activity, plus some strength training 2x/week. The good news for me is that I can pretty much declare that I get that and more, in one form or another, most weeks. There are lists and lists of strategies to make this happen from standing desks to having lunch while walking. Everyone has to do what works best for them. I reject the notion that the sedentary life is all bad. We’ve engineered movement out of life (labor-saving devices, cars, desk jobs) and so now everyone tries to engineer it back in (gyms, fitness trackers, etc.). That works for some and not for others. The single most impactful change most people could make for their health is simply moving more throughout the day. Not necessarily intense exercise (though that helps), just regular movement – walking, standing, taking stairs, anything that breaks up prolonged sitting…or sleeping.
I, for one, feel that the cognitive exercise I get while being sedentary is just as helpful as the movement is when I go about my daily chores. I would rather spend my retirement in a combination of sedentary and non-sedentary activities and balance my cognitive and physical health in a way that pleases me and keeps me in sound spirits. All that said and done…I have to get up now because my Apple Watch tells me I’m due.