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CYCLING PERFORMANCE TIPS

  Last updated: 5/22/2018

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 nonrunners 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 at the 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 nonrunners. 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 nonrunners 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 nonrunners," Fries said. "By and large, the runners have stayed healthy." Not only did running delay disability, but the gap between runners' and nonrunners' 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 nonrunners 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 nonrunners, 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.




REDUCED DISABILITY AND MORTALITY AMONG AGING RUNNERS: A 21 YEAR LONGITUDINAL STUDY.

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.



EXERCISE, INSULIN, AND STAYING HEALTH

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).



GIVE YOUR BABY'S GENES A BOOST

Fifty years before Darwin and his theory of natural selection, Lamarck theorized that an organism would pass on environmental adaptations to its offspring. If you cut 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. You could 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, or are somewhere in between, is called epigenetics. A specific cell protein, miRNA, seems to be the switch that impacts how our hardwired genetic code is interpreted. And lifestyle has been shown to directly impact cell miRNA levels.

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

But surprisingly the researchers also found the same increase in miRNA levels in the sperm of the exercising group as well as improved brain development in their offspring. (It is fair to assume that the same miRNA changes occurred in the eggs of exercising female mice, but it was a 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 did not exercise as they grew. And the grand kids of the original study mice returned to a normal pattern 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 impact miRNA levels, and that miRNA levels can in turn impact other aspects of genetic expression including, for example, 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 genes and in turn your genetic contribution to your kids. But for that extra bit of benefit to be passed on 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 this healthy lifestyle. The exercising mice all benefited from a more connected network of nerve cells in their 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 produce at the local grocery store, or get out for that all too easy to skip afternoon walk, remember that it is not only for you.

The original NYT article that got me thinking.




EXERCISE WILL KEEP YOUR IMMUNE SYSTEM YOUNG

An interesting study on exercise and immunity. It found that "..125 long-distance cyclists, some now in their 80s, .....had the immune systems of 20-year-olds." And a commentary in the lay press.


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