Adaptation: Exercise

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I can’t think of a better example of positive adaptation than exercise. Whether it’s a sport skill, increasing strength, or improving cardiovascular fitness, exercise uses the adaptation principles; the difference is that it’s an intentional act instead of a response to a physical challenge. As an example, let’s use walking or running to improve the fitness of your heart and cardiovascular system as well as every other system involved—which is just about every other system we have.

Let’s begin with how your cardiovascular system would respond to beginning a walking or jogging program. The first walk with a purpose—faster than window shopping and not so fast that you’re stopping to catch your breath every minute—every system in your body is going, “What the heck is going on here?” Your heart may not be used to speeding up like that. The blood isn’t used to traveling that fast. The 5,000 genes that are typically activated when you start to exercise are awake and alert. Your muscles, ligaments, tendons, and stress hormones are challenged, along with the nervous system that controls how the muscles respond to new movement. It’s a mess, but you manage to get through it.

Depending on how hard you pushed yourself, you may feel it. Maybe fatigue a few hours later or sore muscles. That’s why you begin slowly. Save the fastest you’ve ever walked or ran for another time, and get through this first walk.

But by the third walk, your body will start to adapt; your heart rate might not get as high. By the 10th walk, you most likely will be able to maintain a faster pace, but your heart rate may not be as high as the first walk you took at a slower pace. You’re adapting—in fact every system in your body is adapting to the new stress. It will take less effort to do the same work.

You’re not ready for a marathon or maybe even a 5K yet, but exercise is a positive utilization of the adapting ability of your body. You just have to approach it in a systematic way to improve your cardiovascular health.

If you’re the kind of person who needs to see progress to keep going, track your distance, time, heart rate, and so on, but don’t let a few down days discourage you. Sometimes your body needs a bit of time to catch up; stay the course and you’ll soon see improvement again. On the other hand, if you’re the kind of person who hates record-keeping, you’ll still notice improvement—maybe you’ll walk your usual 30 minutes and feel like going another five, or you’ll realize you’re not breathing as hard as you were a month ago. Do what works for you.

I intentionally sent this Memo one day sooner because this is Memorial Day weekend in the U.S. While we celebrate and cherish those who’ve fallen in defense of our country with quiet moments, parades, and fireworks, use the three days to start your fitness program by going for a walk every morning, as long as your physician has no objections to your exercising. By the time you read Tuesday’s memo, you could be on that path to adaptation and a better healthspan than you are right now.

What are you prepared to do today?

        Dr. Chet

Adaptation: Recovery

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In this Memo arc, I’m going to lay the foundation to support my opinion that obesity is a man-made disease. I’m adding this idea to that opinion: reducing body weight and maintaining the weight loss can occur with man-made solutions. Actually, it’s utilizing one mechanism we often overlook that the body uses all the time: adaptation.

Let’s begin with something serious that involves a broken bone or recovery from a joint replacement, which is essentially the same thing. After the bones are aligned, the first phase of the recovery is reducing the inflammation and pain to restore joint mobility. That involves multiple systems of the body working together; hormones are certainly involved as well as the muscular, skeletal, cardiovascular, and other systems as well.

The repair process swings into action to heal the bones, muscles, ligaments, tendons, and other tissues involved. Bones take time to heal because all bones start as cartilage, which is then calcified; that takes six weeks or longer. At the same time, the muscular system has to repair muscles that might have been damaged in the process or are being asked to do other tasks than before.

I could continue, but my point is that the repair process is an adaptation process and takes time, often months and maybe even longer to restore full function. Can we use this process of adaptation in a positive way? I’ll cover that on Saturday.

One thing you can do as we approach the first holiday of the summer is to plan your menu and your exercise sessions. Improving your healthspan is easier if you make a plan for the many exceptions to your everyday routine in advance.

What are you prepared to do today?

        Dr. Chet

Obesity: A Man-Made Disease

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In order to determine whether obesity is an untreatable disease without pharmaceuticals, I took a look at BMI data since 1960. In comparing the BMI of people in the lowest income brackets with the highest income from 1960 through 2024, the lowest income group is always about one BMI unit above the highest income group. The adjusted mean is roughly a BMI of 27 for the poor people versus 26 for the richest people. That continues until the mid-1980s. After that point, the mean BMI continues to rise for the next 40 years—a mirror image with the same one BMI-unit difference.

Mid-1980s

What happened in the mid 1980s that caused the surge in obesity? After checking various sources, there appear to be three factors, not ranked in any particular order.

  • The mid-1980s saw increases in two-income families. There are plenty of economic reasons for that, but the net effect was less time spent preparing food in the home and a reliance on convenience food purchases.
  • There was an increase in fast-food drive-thrus and take-out foods. Since COVID, there is more reliance on food delivery.
  • The mid-1980s saw an increase in ultra-processed foods. Using inexpensive ingredients, particularly carbohydrates and fats, and filled with flavor enhancers that accented the salty and umami, the amount of ultra-processed food has risen to over 50% of the typical American’s diet.

She was asked, “If people stop using GLP-1, will they gain back the weight?” She said yes because there’s no other way to maintain weight loss because of the fat setpoint. I just can’t accept that premise.

The Bottom Line

Overweight and obesity appear to be man-made diseases because of the environment we live in today with so much easily available food. However, I cannot accept that the fat setpoint is permanent. Yes, there are many factors in the brain, the pancreas, and the digestive system that control the feelings of hunger and the anticipation of food, but that doesn’t mean you really need nutrition. You and I just have to learn to ignore those signals that say, “what will my snack be?” when we’re still stuffed from dinner. We must take command. I’m not suggesting it will be easy, but it’s not impossible. In my mind, it’s a lot easier than taking a medication every day for the rest of my life.

What are you prepared to do today?

        Dr. Chet

References:
1. Int. J. Environ. Res. Public Health 2024, 21, 73.
2. Stat Pearls. 2025. Obesity and Type 2 Diabetes

Is Obesity a Disease?

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In a podcast about GLP-1 receptor agonists and several new medications that are under development, the expert was a researcher on the cutting edge of what these peptides can do for weight loss. A couple of things she said didn’t sit right.

One was that obesity is a disease of genetic tendencies to store fat more effectively and create a body-fat setpoint. The implication is that in a land of food abundance, specifically ultra-processed food, the setpoint could be raised but never lowered without medical intervention. The second was that these medications are the best solution for obesity, and thus people will have to take the medications for life or they’ll gain back weight.

According to the World Health Organization and just about every other medical society in the world, overweight and obesity are defined as abnormal or excessive fat accumulation that presents a risk to health. But is it as simple as that? Based on a recent paper, the risk of getting type 2 diabetes is 7% to 12% in men and women at a BMI of 30; as BMI increases to over 40, the risk goes up to 74% for both men and women. It’s not an excuse to stay obese, but does it mean someone who is obese will get the diseases associated with obesity?  I have more questions, and I’ll cover them on Saturday.

Insider Conference Call is tomorrow night. The topics of the evening are reviewing the top five foods that prevent cancer as well as answering Insider questions. Interested? Become an Insider by 8 p.m. Wednesday and you can join in.

What are you prepared to do today?

        Dr. Chet

References:
1. Int. J. Environ. Res. Public Health 2024, 21, 73.
2. Stat Pearls. 2025. Obesity and Type 2 Diabetes

Absolutely Monumentous!

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Happy Mother’s Day to all the mothers who perform monumentous tasks every day. For those of you who still have your mom in your life, make it a habit to treat your mom like every day is Mother’s Day. It’s similar to working on your health. It’s not what you do once in a while that matters; it’s what you do every day.

London Marathon

Back to the monumentous marathon. The world record and two-hour mark was broken five years ago in an unofficial marathon run on a track under ideal conditions. But running under track conditions, much like breaking the four-minute mile, is different while being paced by other elite runners compared to running a race on the road.

While reading about the prep for the race, much was made of the weight and construction of the Adidas running shoe and justifiably so. The Adidas Adizero Adios Pro Evo 3 weighed in at 97 grams—similar to a pack of cards or 20 sheets of paper—with a variety of other features to make the shoe strong and durable.

I checked the weight of my new running shoes. They are a dream to walk in, and I can’t wait to finally start running again. My running shoes weigh in at a whopping 339 grams—almost 3.5 times more! That works out to about four ounces per shoe lighter, every step, for 26.2 miles. If I were still running marathons, I’d probably not buy a $500 pair of shoes, but I’d be tempted.

The Training

While the shoe is important, and I won’t diminish the impact in any way, it is the training that makes the runners elite. While I have no knowledge of his specific training programs, I would wager it consisted of three specific factors:

  • Long, slow distance, mostly at altitude
    The purpose is to get used to running long distances. Running at altitude adapts the body to less oxygen in the blood so when he comes back to sea level where there’s more oxygen in the air, he can gain an advantage. Just realize that for him and other elite runners, that pace might be 5:15 to 5:30 per mile and 6 miles per hour for her.
  • Interval training to raise the lactate threshold
    Running intervals just to the point where lactic acid starts to build up allows the body to increase stamina. Short version: effort over time increases.
  • Exact nutrition
    I would imagine every calorie is accounted for as to composition, time in relation to training, and specific tapering so he and she were both primed to run fast.

One thing to realize is that runners at this level eat, train, and sleep—that’s it. But that’s also what they get paid to do. There are some estimates that Sawe earned over $350,000 for his victory.

The Bottom Line

I bet neither you nor I are going to become elite marathon runners any time soon, but the consistency of their efforts is what we need in our lives. We need to make the time to do the things we can do day in, day out, to increase our healthspan. Maybe getting better walking/running shoes instead of the $20 tennies we’ve had for five years might be a good investment. A lifetime of abuse adds up and can make walking difficult as we reach old age. Respect your feet, starting when you’re young, and you’ll be able to keep going for longer.

What are you prepared to do today?

        Dr. Chet

Reference: Photos courtesy of Adidas Media

Monumentous Marathon

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Once in a while, something happens that you need a made-up word to describe. More than momentous, more than monumental, the new world record for the marathon was more than that. It was monumentous: four athletes broke the world record for the men’s and women’s marathon.

At the London Marathon in late April, the official world record for the marathon (that’s 26.2 miles) was broken for both the male and female marathons. More than that, it was shattered by three male runners and one female runner. Kenyan Sabastian Kimaru Sawe’s winning time was 1:59:30, more than a minute faster than the previous record. Two more men crossed the finish line under the prior world record time. Tigist Assefa broke the women’s world record with a time of 2:15:41 and broke her own world record by nine seconds.

Without question, this was a monumentous event. Was it inevitable? I’ll give you my thoughts on that and more on Saturday.

What are you prepared to do today?

        Dr. Chet

Reference: Photos courtesy of Adidas Media

I Can See Clearly Now

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I left you with some questions I had to ponder and have gotten a couple more. Then I’ll leave you with the answer I posed to my ocular surgeon.

Glaucoma

Glaucoma is not just a single ocular disease; there are several types. Some are related to how well the eyes drain fluid; some drain slowly while others seem to get plugged. The key to limiting damage is to get the pressure down by draining excess fluid. While there are still more types, the most important thing is to know your family history. There’s genetic testing available, but it’s not always predictive of what will happen to an individual, because some forms of glaucoma are caused by a combination of genetic factors.

Regular ocular pressure tests are the best way to find out whether the pressure in the eye is normal or not. If I had not gone in to get new glasses, I would not have gotten a diagnosis until later and may have lost even more vision.

Cataracts

There’s really nothing you can do to prevent cataracts because it’s partially a function of aging. However, you can protect your eyes by wearing UV protection sunglasses to reduce the impact of sunlight; it’s always better the earlier you start, so keep that in mind with the kids and grandkids. Other steps we can take are to quit smoking and keep blood sugar under control.

Two questions I’ve gotten are about the types of lenses and the cost. I got the simplest mono-focal intraocular lenses because my distant vision was my primary concern. The glaucoma created the need for reading glasses to balance both eyes.

If you’ve always worn corrective lenses, those issues can be addressed depending on the type of lenses. The person who knows that best would be your ophthalmologist. The cost will vary depending on what you want the lens to do. It also depends on the type of health insurance coverage you have. The American Academy of Ophthalmology has a Q&A on lenses at the link below. It’s obvious to me that eyecare is a good investment because it affects your quality of life and productivity.

The Bottom Line

I asked my surgeon the question about how to prevent cataracts and glaucoma. He thought about it and said prevention can be tenuous, so the best thing to do to keep your vision as long as you can is to get regular eye exams every year; that will protect your vision as well as keeping your glasses up to date to reduce eye strain. That seems like sound advice to me. Just another step to improve our healthspan.

What are you prepared to do today?

        Dr. Chet

Reference: https://www.aao.org/eye-health/tips-prevention/best-artificial-lens-implant-iol-cataract-surgery

My Eyes!

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No, it’s not like when Phoebe saw Monica and Chandler kissing on Friends—but it is rather dramatic.

Let me recap my vision story. My dad died at 41, so I have no info from him or his family. My grandmother had cataracts removed when she was about 70. It led to a decline in her health; she never could get used to the glasses with thick lenses that looked like the bottom of Coke bottles. Remember, lens replacement as we have today didn’t become common until the mid-1980s. My mother had glaucoma, which was the genetic factor in my development of glaucoma.

I still remember the exact moment I discovered I needed reading glasses. I had been given a badge to enter campus during an international sport competition, and I couldn’t read the fine print on the badge. My real journey began when I finally had an eye exam about 10 years ago. The ophthalmologist tested me for glaucoma and the numbers were high—over 30 in each eye, and it should be below 8. Prescription eye drops lowered the pressure, but they can’t repair the damage I have in my right eye. Neither the cataract surgery nor the drains can repair it. I consider myself lucky it wasn’t more severe.

As for my vision about a month after the first replacement? I would say it’s excellent—over 18 inches away. I typed this without glasses at all in a 12-point font. I still need glasses for reading to help the eye with the lost vision, but that seems relatively easy.

The questions I have are: what could I have done to prevent either condition? And what should you and I do in the future? I’ll cover that on Saturday.

What are you prepared to do today?

        Dr. Chet

Again with the BMI?

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I got an email from a long-time reader about a recently published study comparing BMI calculated from height and weight with percent body fat calculated via Dual Energy X-Ray Absorptiometry commonly called DEXA. The objective of the study was to see if BMI was accurate in predicting the differences between underweight, normal weight, and several degrees of overweight and obesity with measure of body fatness.

Their subject pool was 1,351 Caucasian men and women 18–98 years old. This was a cross-sectional study (and more than likely a retrospective study) of patients in Italy who had their body fat assessed via DEXA between 2013 and 2024. While this paper contained hundreds of numbers, the essence of what they found was that for those with normal-weight BMI, body fatness was accurate, but for underweight and overweight and obese subjects, BMI under or overestimated their actual body fat; in the chart above, a red dot indicates someone whose BMI was misclassified. The authors felt that the World Health Organization should consider more research because the misclassification may impact diagnostic capability and thus lead to unnecessary treatment protocols.

Why BMI Should Still Be Used

I think the researchers are wrong in their conclusion for the following reasons:

  • While there were definite points where people were misclassified based on the graphic presentation of all data points, it was mostly on the margins. Is there a difference between a BMI of 24.5 versus 25.5? Is there a real difference in a person who has a BMI of 33.0 versus 36.0? Because of the way the data were analyzed by weight classification, the measure loses the nuance.
  • Regardless of the numbers, a physical examination by the healthcare professional should confirm whether a person is normal weight or overweight based on the fluffiness factor. People of the same height and weight may look muscular or like the doughboy of commercials.

The Bottom Line

The question of using BMI as a measure of body fatness in large groups will probably never be over. But when assessing large groups of people, it’s still the best measure for an overview of whether a population is underweight, normal weight, or overweight. If people really need to know more, they can always pay to have a DEXA scan done.

On a personal level, will it really give you any more information than when you stand naked in front of a mirror? When you know, you know. The important question is what are you going to do about it?

What are you prepared to do today?

        Dr. Chet

Reference: Nutrients. 2025. https://doi.org/10.3390/ nu17132162

When in Doubt…

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When I was doing a post-doc in the late 1980s, I was part of a team of researchers who tested a group of swimmers. This was one of four parts of an overall documentary on an innovative look at health by the PBS’s Nova. I had about a half-second of screen time in this PBS film and that was it; no YouTube or Instagram videos to show. But the segment that had the most impact on me was a section on what to do when you think you’re having a heart attack.

The film crew happened on a case where a man didn’t feel right and thought he was having a heart attack, so he went to see his cardiologist. The nurse said he should go to the emergency room. He drove there by himself. There were many factors pointed out by an ER doc, but here are the two most important lessons:

  • Heart attack pain can vary but most often presents itself as an elephant sitting on your chest and you can’t breathe.
  • Call 911 or if you are close to an ER, have someone drive you but don’t drive yourself. Ambulance personnel know what to do to prevent further damage to your heart if it’s a heart attack, not to mention that they’re less likely to pass out.

Since watching that documentary, my mantra is when in doubt, check it out. Now.

During tomorrow night’s Insider Conference Call, I’m going to talk about two primary topics: the potential use of vaccines to prepare for future infections and the timing of intermittent fasting. If you become an Insider by 8 p.m. ET Wednesday evening, you can participate in the call and get your questions answered.

What are you prepared to do today?

        Dr. Chet