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  Last updated: 1/31/2021


BE ACTIVE, STAY HEALTHY - a commentary by Erin Digitale

Regular running slows the effects of aging, according to a new study from the Stanford University School of Medicine that has tracked 500 older runners for more than 20 years. Elderly runners have fewer disabilities, a longer span of active life and are half as likely as aging non runners to die early deaths, the research found.

The study has a very pro-exercise message," said James Fries, MD, an emeritus professor of medicine at the medical school and the study's senior author. "If you had to pick one thing to make people healthier as they age, it would be aerobic exercise. "The new findings appear in the Aug. 11 issue of the Archives of Internal Medicine.

When Fries and his team began this research in 1984, many scientists thought vigorous exercise would do older folks more harm than good. Some feared the long-term effect of the then new jogging craze would be floods of orthopedic injuries, with older runners permanently hobbled by their exercise habit. Fries had a different hypothesis: he thought regular exercise would extend high quality, disability free life. Keeping the body moving, he speculated, wouldn't necessarily extend longevity, but it would compress the period atthe end of life when people couldn't carry out daily tasks on their own. That idea came to be known as 'the compression of morbidity theory."

Fries' team began tracking 538 runners over age 50, comparing them to a similar group of non runners. The subjects, now in their 70s and 80s, have answered yearly questionnaires about their ability to perform everyday activities such as walking, dressing and grooming, getting out of a chair and gripping objects. The researchers have used national death records to learn which participants died, and why. Nineteen years into the study, 34 percent of the non runners had died, compared to only 15 percent of the runners.

At the beginning of the study, the runners ran an average of about four hours a week. After 21 years, their running time declined to an average of 76 minutes per week, but they were still seeing health benefits from running. On average both groups in the study became more disabled after 21 years of aging, but for runners the onset of disability started later.

"Runners' initial disability was 16 years later than non runners," Fries said. "By and large,the runners have stayed healthy." Not only did running delay disability, but the gap between runners' and non runners' abilities got bigger with time. "We did not expect this," Fries said, noting that the increasing gap between the groups has been apparent for several years now. "The health benefits of exercise are greater than we thought."

Fries was surprised the gap between runners and non runners continues to widen even as his subjects entered their ninth decade of life. The effect was probably due to runners' greater lean body mass and healthier habits in general, he said. "We don't think this effect can go on forever," Fries added. "We know that deaths come one to a customer. Eventually we will have a 100 percent mortality rate in both groups."

But so far, the effect of running on delaying death has also been more dramatic than the scientists expected. Not surprisingly, running has slowed cardiovascular deaths. However, it has also been associated with fewer early deaths from cancer, neurological disease, infections and other causes. And the dire injury predictions other scientists made for runners have fallen completely flat. Fries and his colleagues published a companion paper in the August issue of the American Journal of Preventive Medicine showing running was not associated with greater rates of osteoarthritis in their elderly runners. Runners also do not require more total knee replacements than non runners, Fries said.

"Running straight ahead without pain is not harmful," he said, adding that running seems safer for the joints than high impact sports such as football, or unnatural motions like standing en pointe in ballet. "When we first began, there was skepticism about our ideas," Fries said. "Now, many other findings go in the same direction." Fries, 69, takes his own advice on aging: he's an accomplished runner, mountaineer and outdoor adventurer.


The benefits of a plant based diet can be magnified by adopting the strategyof Time Restricted Eating (TRE). This article reviews the conceptand speculates as to why it is a healthier way to eat.

A few of the highlights for me:

  1. It is better to eat the majority of your calories before 3 PM in the afternoon.

    "The eTRE intervention by Sutton et al. revealed hyperinsulinemia was reduced when daily eating was completed by 1500 h, but such a strict eating protocol is not likely to be practical or socially acceptable at a population level. Studies of "late" TRE, or when total energy intake was restricted to meals consumed after 1600 h, have resulted in impaired fasting glucose, lowered glucose tolerance, and increased ratings of hunger."

  2. If you are already exercising regularly, adding TRE would appear to add minimal additional health benefits. I suspect this is even more so if you eat the majority of your calories in the middle of the day.

    "However, we propose that for most "healthy" individuals, adding TRE to a program of regular physical activity would impart minimal additive effects on a range of health-related outcomes."

If you have decided to make changes in your daily routine to improveyour long term health, and want to pick a place to start - diet changes versus adding regular exercise to your dailyroutine - exercise gets the nod.

"We believe that exercise training undertaken in accordance with national and international guidelines imparts greater whole-body and tissue-specific metabolic health benefits than any current dietary intervention. "But of course these two interventions are not mutually exclusive. Most of us already exercise regularly. But after doing some reading on the pros and cons of TRE, I've also chosen to move the bulk of my calories to midday and skip an early breakfast (other than my coffee). I also avoid carbohydrates as much as possible for my evening meal, going heavy on salads and vegetables. I'm not sure I will be any healthier in the long run, but I can say I feel much more comfortable after my dinners these days.

For more on TRE.


Two interesting papers.

First, from the American Journal of Cardiology.5000 men followed up to 50 years. Those in the top 5% of cardiovascular fitness lived almost 5 years longerthan those in the lowest 5 percent.

We often "hear" that you can "injure" your heart by exercising too much. This study also puts that idea to rest.

In a second, group of 191 Swedish women, 38-60 yearsof age in 1968, were givenan ergometer cycling test. When their mental status was valuated in 2010 (forty years later), it wasfound that the women with high physical fitness at middle age were nearly 90% less likely to have developeddementia compared with the women who were only moderately fit.


The last few years have seen a dramatic increase in the number and type of tools formetabolomic investigations. This paperis a fascinating example of how detailed these investigations into exercise physiology have become.

First, a couple definitions:

The following are excerpts from a New York Times review of the work.

Scientists "decided complete a full census of almost every molecule that changes when we work out."Study participants were "asked complete a standard treadmill endurance test, running atan increasing intensity until exhaustion, usually after about nine or 10 minutes of exercise."Blood was drawn at time 0, immediately after this exertion, and again 15, 30 and 60 minutes later.

The scientists "...measured the levels of 17,662 different molecules. Of these, (the concentrations of) 9,815 - or morethan half of those studied - changed after exercise. Some increased. Others declined.Some gushed immediately after the exercise, then fell away, while others lingered in heightened or lowered amounts for an hour after the workout. The types of molecules ....ranged widely, with some involved in fueling and metabolism, others in immune response,tissue repair or appetite."

This study highlights the complexity of human physiology. For most of us, it is enough to know thatexercise helps keep our system younger. How exercise achieves that end is buried in these 9815 organic molecules. But each ofthese thousands of molecules, once categorized and studied in detail, will give the clues we need toimprove the health of those not as compulsive about doing their intervals. Andthe hope that following blood levels of a subset of these molecules might give us the clues we need to maximize improvement with a truly individualized training program.

If you exercise regularly for health reasons, physiologists used a similar approach (originalresearch) to compared the effects of resistance andaerobic exercise on that part of the metabolome that impacts cardiac health. Their impression - aerobic exercise provided more cardiovascular benefits than resistance training.


Chakravarty EF, Hubert HB, Lingala VB, Fries JF.

Exercise has been shown to improve many health outcomes and well-being of people of all ages. Long-term studies in older adults are needed to confirm disability and survival benefits of exercise. METHODS: Annual self-administered questionnaires were sent to 538 members of a nationwide running club and 423 healthy controls from northern California who were 50 years and older beginning in 1984. Data included running and exercise frequency, body mass index, and disability assessed by the Health Assessment Questionnaire Disability Index (HAQ-DI; scored from 0 [no difficulty] to 3 [unable to perform]) through 2005. A total of 284 runners and 156 controls completed the 21-year follow-up. Causes of death through 2003 were ascertained using the National Death Index. Multivariate regression techniques compared groups on disability and mortality.

RESULTS: At baseline, runners were younger, leaner, and less likely to smoke compared with controls. The mean (SD) HAQ-DI score was higher for controls than for runners at all time points and increased with age in both groups, but to a lesser degree in runners (0.17 [0.34]) than in controls (0.36 [0.55]) (P < .001). Multivariate analyses showed that runners had a significantly lower risk of an HAQ-DI score of 0.5 (hazard ratio, 0.62; 95% confidence interval, 0.46-0.84). At 19 years, 15% of runners had died compared with 34% of controls. After adjustment for covariables, runners demonstrated a survival benefit (hazard ratio, 0.61; 95% confidence interval, 0.45-0.82). Disability and survival curves continued to diverge between groups after the 21-year follow-up as participants approached their ninth decade of life. CONCLUSION: Vigorous exercise (running) at middle and older ages is associated with reduced disability in later life and a notable survival advantage.


The following is form a post on the CPTIPS Facebook page.

When you think about the health benefits of exercise the usual association is with improving or maintaining your cardiovascular health. But its impact on your metabolic health may be equally as important in disease prevention.

This article suggests that a successful weight loss program can correlate with a "re-setting" of your body's cell sensitivity to the effects of the hormone insulin e important in carbohydrate metabolism. The medical literature supports the beneficial effects of exercise on carbohydrate metabolism, not only by its direct, insulin independent movement of carbohydrate into exercising cell (thus decreasing demands on the pancreas cells that make insulin) but also to increase insulin effectiveness (which also translates into a decreased demand on the pancreas). And this enhancement of the effectiveness of insulin lasts up to 16 hours after a bout of strenuous exercise.

So not only will an exercise program help you if you are trying to lose (and maintain) a new weight, for those of us of normal weight, it MAY decrease the odds of developing diabetes by decreasing insulin production demands on the pancreas cells (this is speculation on my part, but all the facts point in this direction).


Fifty years before Darwin and his theory of natural selection, Lamarck theorizedthat an organism would pass on environmental adaptations to its offspring. If youcut the tails off three or four generations of mice, you'd soon see a few tail-less babies. Darwin,on the other hand, felt that our genes were hardwired and inherited unchanged from our parents.And then passed unchanged to our kids. Life experiences did not affect future generations. Youcould cut off as many mouse tails as you'd like but would never see tail-less mice in future litters.

This assumption of a hard wired inheritance ruled the science of genetics for over a hundred years.However the last few decades have seen a shift in this absolutist view. Why are two identical twins(exactly the same genetic makeup or genotype) often slightly different in appearance (phenotype)?

The study of differences in genetic expression, that is how identical genes are turned on, off, orare somewhere in between, is called epigenetics. A specific cell protein, miRNA, seems to be theswitch that impacts how our hardwired genetic code is interpreted. And lifestyle has been shownto directly impact cell miRNA levels.

A recently published study on brain physiology shows the link between the increase in miRNAlevels in the brains of regularly exercised mice and a corresponding increase in brain nervecell connections. This was not unexpected as we knew from prior investigations that the level ofour exercise directly correlates with brain health.

But surprisingly the researchers also found the same increase in miRNA levels in the sperm ofthe exercising group as well as improved brain development in their offspring. (It is fair toassume that the same miRNA changes occurred in the eggs of exercising female mice, but it wasa lot easier for the experimenters to collect sperm from male mice than harvest eggs from the females).

These elevated miRNA changes in the babies soon returned to normal levels if the baby mice didnot exercise as they grew. And the grand kids of the original study mice returned to a normalpattern of mouse brain development as would be expected with a similar, unaltered genetic makeup.

Even though this study focused on exercise, we know that other daily activities and exposures can impactmiRNA levels, and that miRNA levels can in turn impact other aspects of genetic expression including, forexample, cancer development.

It has been speculated that exposure to toxins in our environment (pesticides for example),medications and illicit drug use, and even diet can impact on our miRNA. Thus our development(and our kids in turn) is not just limited to the genes we inherit from our parents (and their parents).

This means that you can have direct, but limited, control to maximize the benefits of your genesand in turn your genetic contribution to your kids. But for that extra bit of benefit to be passedon to another generation, your kids would also have to adopt a similar "healthy" lifestyle.

And while you are helping give your kids a healthy boost to their genes, you will benefit from thishealthy lifestyle. The exercising mice all benefited from a more connected network of nerve cells intheir brains which it can be speculated will translate into a decreased tendency to develop Alzheimer's.And we also have that suspected link between miRNA levels and cancer development.So when you are vacillating on that decision to buy the slightly more expensive pesticide free produceat the local grocery store, or get out for that all too easy to skip afternoon walk, rememberthat it is not only for you.

The original NYT article that got me thinking.


This interesting study on exercise and immunityfound that "..125 long-distance cyclists, some now in their 80s, .....had the immune systems of 20-year-olds."

As nicely summarized by Dr. Mirkin"T-cells recognize foreign proteins on the surface of invading germs and cancers to tell your immunity to attack and killthese cells. They then stimulate your immune system to make antibodies to attach to and kill invading germsand cancer cells, and produce chemicals called cytokines that activate other T-cells to remove germs andcancer cells from your body. Other regulatory T-cells dampen down your immunity so that your immunity doesnot attack and destroy your own healthy cells."

The study suggests that this weakening of the aging immune system is from a significant reduction in thymicactivity and the production of T cells. This senescence is blunted in regular cyclists, and to quote: "....many features of immune senescence may be driven by reduced physical activity with age."


Some of us exercise to improve our aerobic capacity for our weekend group ride withfriends or competitive events. But many more have taken on a regular exercise program toimprove their cardiovascular health (lower the risk of a heart attack) or after being toldthey had an elevated fasting blood sugar and were borderline diabetic.

For improving athletic performance, timing of the days training is determined by whatworks to maximize a regular training schedule. But for metabolic health, especially for thosewith altered glucose metabolism, thispaper indicates that the timing of exercise will make a difference in health benefits gained.

To quote from a NYT article on the study: "After 12 weeks, the men who had pedaled inthe afternoon displayed significantly better average insulin sensitivity than themorning exercisers, resulting in a greater ability to control blood sugar. They alsohad dropped somewhat more fat from around their middles than the morning riders,even though everyone’s exercise routines had been identical."

So if you have the flexibility, a vigorous walk or hour on the bike in the afternoonprovides more health benefits than exercise in the early morning. I personallyprefer a walk immediately before or after my noon or evening meal as timing of thisexercise (which stimulates glucose movement into the muscles) blunts the postmeal blood sugar rise. And more and more work is pointing to the height of that bloodsugar spike as a culprit in the development of cardiovascular disease.


To improve your VO2max (aerobic performance), HIT (intervals) are definitely the way to go.But for general health - BP control and lipid management -this paper indicates longer and less intense is better.

To quote from a NYT review: "...the results indicate that intervals and traditional exercisealter our bodies in divergent ways, and we may want to consider what we hope to achievewith exercise when choosing how best to exercise.....All exercise is good, but thereare nuances. Frequent, almost-daily moderate exercise may be preferable for improvingblood pressure and ongoing blood-sugar control, compared to infrequent intervals, while a littleHIT is likely to get you in shape as effectively as hours and hours of easier cycling orsimilar exertion."

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