Continuing on "The Weight of a Life That Matters", let's explore further along the line of how best to take care of our physiology or, at the very least, have a way to track how we are doing so that the rest of our journey is still fun and relatively free of the usual concerns about fitness and general well being for those among us of a certain age. So let's get right to it.
Those are all acronyms in the title, the first one is likely the least known -
(HRV) Heart Rate Variability - but we'll get to it later. REM, you're likely familiar with because it stands for Rapid Eye Movement and it is the most essential of all our sleep cycles. It is during that time, our dream cycles, when our brain does all the sorting of our memories, regulates our emotions and more importantly, sharpens our cognitive functions.
What this means is that our physiology begins and ends with how well our brain is working. It is the central processing unit (CPU) that regulates and controls everything that is happening to our body - from growing fingernails to producing insulin, how we feel warmth or cold, discerning the differences between ideas or arguments, to producing red blood cells, etc. It can do that because this particular CPU has 90 billion neurons to rely on that can do 100 trillion connections at a time. To give you an idea of the enormity of that capability, try to imagine counting one connection per second. You will still be counting for the next 30 million years; your brain makes those entire connections at a moment's notice. It comes with a price, of course. For a body part that is a mere 2% of our body weight, it consumes 20-25 % of all the calories that our body processes from all the nutrients that it consumes.
Now, the super computer that beat Kasparov in chess was one roomful of interconnected computers, manned and maintained by several technicians and engineers, air conditioned to low room temperature settings and consumed several hundred watts per minute. Kasparov's brain weighed a mere three pounds, powered by what he had for lunch and dinner.
So, first things first. We need to take care of our brain. It does not demand much. Proper diet is good. But what it needs the most, fundamentally and by necessity, is a good night's sleep. But what is a good night sleep? A decade or so ago short of a laboratory setting, electrode attachments and other monitoring tools, there was little the average person can do to collect and retain data on basic breathing and heart functions when our bodies are physically stressed during exercise or when at rest. More on this in a bit.
Now, our body is a machine and runs like an engine. Our nose, mouth, and trachea make up the air intake manifold. Air exchange is done by the lungs where red blood cells carry oxygen that is pumped through the heart to mix with fuel (food and/or drinks) during digestion and waste in our blood is filtered by the kidney. If we allow our brain a good rest and recovery, exercise our heart and keep our kidneys at optimum filtration capacity we shall have achieved more than half of what is required for proper maintenance. It is a given that every body part is essential; however, the brain, heart and kidneys are the super parts. This takes us to the acronyms in the title of this blog.
Almost three years ago I parlayed some amount with a purchase of a smart watch. It was not the most expensive by any means but I was quite surprised at what it is able to keep track of. Actually, all I needed it for was to keep track of the number of laps and the time it took me to swim 1000 meters in the pool. Before that I merely counted the laps in my head and check time it took me to do it on my old watch. This new watch, however, will also track a lot of other data not related to swimming. It can be used for tracking walking steps and running and even for golf, once the golf app is downloaded to your phone.
First the swimming part. Once set with the proper length of the pool it counts the laps for me automatically and records not just the total time but time for every 100 yards, best and slow time per lap, number of strokes, average stroke per minute and per length, speed in mph, the average heart rate and recovery time in hours. Based on my age, which is part of the input it kept on record, it advises me a recovery time of 24-26 hours, which actually means I need to rest for at least one day before swimming again. I assume if I were younger I could probably swim everyday.
Then here is the other data it tracks and keeps. The watch is linked to my phone and all throughout the day it tracks a lot of stuff that includes the number of walking steps. For example, even though walking is not an exercise regimen for me, it still tells me that on average I managed 6-7,000 steps!
Here comes the HRV. It is a measure in milliseconds of time between heartbeats. Now, there's no universal "good" or "bad" HRV number'. However, that number tends to decline with age. The number can get lower between heartbeats which means a slightly faster normal heart rate.
Age Group Typical Range (ms)
20-29 40-80
30-39 35-70
40-49 30-60
50-59 25-50
60+ 20-45
Important: These are approximations. Someone with an HRV of 25 isn't necessarily unhealthy, and someone with an HRV of 90 isn't automatically in great shape. Your personal baseline is what matters.
- Age (HRV naturally declines with age, and ranges differ for children)
- Fitness level (trained athletes typically have higher HRV)
- Genetics (some people naturally run higher or lower)
- Sex (women often have different patterns than men)
- Health conditions (various conditions affect baseline HRV)
To paraphrase, a higher HRV - longer elapse time from one heartbeat to the next - means that a high HRV means a lower heart rate as to be working less than a faster one given the same set of conditions. But that is not all that matters. Resting heart rate (RHR) is a much better gauge. Given the same conditions, a lower resting heart rate indicates that the heart does not need to beat fast to push or pump the same amount of blood while at rest so that there is still a lot of head room when vigorous exertion is needed.
Tour de France cyclists are known to have RHR at between 35-40 beats per minute. A Guinness world record is 28 for one older gentleman who apparently by mere genetics was endowed with a rare, slow running heart when at rest.
The benefit of exercise, swimming in my case, results in my low RHR of a daily average of 50 beats per minute and an average high of 113 while swimming. The watch also records during sleep my breaths per minute (BRPM). "Vigorous" times, expressed in minutes, indicate level of exertion on a daily basis.
The bottom line is that a smart watch like this is and should be an investment in your health to keep track of some activities that may matter for proper assessment. I think it's a good investment.
For general guidelines in day-to-day maintenance of our health I came up with the last acronym in the title above - 'She'. It stands for Sleep, Hydration and Exercise.
Sleep, as mentioned earlier, has a profound effect on brain health and cognitive ability. (Refer to my earlier blog - To Sleep Perchance to Dream). Hydration or our intake of the proper amount of water everyday, typically 8 cups per day, deserves our special attention.
Just a few years ago my primary care doctor referred me to a renal (kidney) specialist because based on my blood work results my eGFR was 1-2 points below the minimum. The acronym stands for estimated Glomerular Filtration Rate. Factoid: Today, there are 10,840 stand-alone dialysis centers (excluding those in hospitals) in the U.S., making it almost the largest health-related "cottage industry", second only to the number of urgent care clinics nation-wide at 11,900. Kidney disease has become a a serious chronic disease. Today it is estimated that there are 100,000 patients waiting for donor kidneys on a wait list of three years or more.
"When looking at your eGFR results, a higher number is better. In general, an eGFR value lower than 60 is a sign that your kidneys may not be working properly. An eGFR lower than 15 is a marker of kidney failure".
Today, there are 37 million Americans with chronic kidney disease (CKD) that come in 5 stages, although the last one is the one that is critical (likely to need a transplant).
This takes us to proper hydration. Not too long ago I was at my renal doctor's office for my check up. She sees me once a year as she monitors and assesses the results of my bloodwork. I mentioned to her that recently I started closely monitoring my water intake and I realized how far off I was with my hydration when I started monitoring via the same app as on my cellphone that picks up data from my watch. She told me to have another blood work in a month to see what my eGFR is going to be, now that I am strictly keeping to an 8 cup regimen of water intake. I start my morning even before breakfast or coffee with two glasses of lukewarm plain water. Much of my hydration, as recommended, is consumed in the first half of the day - 5/6 cups before lunch. I do not count the 2 cups of coffee.
Sure enough my eGFR greatly improved (the higher the better, 60 being the bottom floor). I mentioned this to my primary care doctor two months later during my annual physical. Along with my routine blood work, she ordered an eGFR test as well. The result was another above 60 reading. For my age that looks fine to the doctors. However, 90 and above is what is expected of young kidneys and the range of 60 and above but below 90 can be an early onset of chronic kidney inefficiency. As we get older maintaining an above 90 reading is an uphill effort for kidneys. Doctors therefore look at anything over 60 for the older folks as acceptable.
Anecdotally, not a scientific finding or statement by any means, I would like to believe that perhaps all I needed all along was proper hydration. And, believe it or not, hydration is likely the one less likely given the same attention as we do with diet and exercise in most people's hectic modern life. So, drink water conscientiously at 8 cups per day.
Exercise by almost universal acclimation is needed so we will not spend any more time on it. Instead, let's pay attention to the brain - especially towards how best we can keep it healthy as we travel through the latter years.
For a very long time it was believed that we're stuck with the number of neurons at birth, then we tend to lose some to a diminishing number of about 10 per cent in old age. But there is good news of late.
"In 1962, scientist Joseph Altman challenged this belief when he saw evidence of neurogenesis (the birth of neurons) in a region of the adult rat brain called the hippocampus. He later reported that newborn neurons traveled from their birthplace in the hippocampus to other parts of the brain. In 1979, another scientist, Michael Kaplan, confirmed Altman’s findings in the rat brain; and in 1983, he found special kinds of cells—called neural precursor cells—with the ability to become brain cells like neurons, in adult monkeys".
Considered at first to be true only in animals it is now believed that we can grow new neurons. It is still new in the field of neuro-science but according to Science News Today:
"The adult brain is not a static organ but a living, changing system, capable of reorganizing itself, forming new connections, and, in specific regions, generating new neurons. This remarkable capacity is known as neuroplasticity".
"Neuroplasticity refers to the brain’s ability to change its structure and function in response to experience, learning, environment, and injury. It operates at multiple levels, from molecular changes within individual neurons to large-scale reorganization of entire neural networks. Through neuroplastic processes, the brain adapts continuously, sculpted by how we think, move, feel, and interact with the world. This adaptability is not a rare or exceptional phenomenon; it is a fundamental property of nervous systems".
My wife had commented once that even though English is my second language I write better with it now than from way back when long before I retired in 2007. I said that is because I never stopped learning it; together with a host of other stuff deemed to be in a class of so called useless information. Actually, I have news for everyone. There is no such thing as useless information as far as the brain is concerned. To the brain, information or processing information is what it wants to do. Denied of new information, nothing to work on to stimulate it, or be entertained by it, the brain loses interest to the point of stagnation.
I said in one of my earlier blogs that the universe is made up mainly of three components: matter, energy and information. The brain needs all of them: gray matter that it is made of, energy to keep it going, and information to keep it entertained, uses it, stores it and disburses it.
As the saying goes, use it or lose it.
Keep it entertained and it will serve us all well.
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