I came across yet another study done on exercise that I wanted to share (am I overdoing this whole exercise study thing here? Please let me know. But I do find these studies endlessly fascinating)

We all know that physical activity is beneficial in countless ways, but even so, Dr. Mark Tarnopolsky, a professor of pediatrics at McMaster University in Hamilton, Ontario, was startled to discover that exercise kept a strain of mice from becoming gray prematurely.

But shiny fur was the least of its benefits. Indeed, in heartening new research published recently in The Proceedings of the National Academy of Sciences, exercise reduced or eliminated almost every detrimental effect of aging in mice that had been genetically programmed to grow old at an accelerated pace.

In the experiment, Dr. Tarnopolsky and his colleagues used lab rodents that carry a genetic mutation affecting how well their bodies repair malfunctioning mitochondria, which are tiny organelles within cells. Mitochondria combine oxygen and nutrients to create fuel for the cells. ( Just to let you know, mitochondria are microscopic power generators. I learn from these studies too)

Mitochrondria have their own DNA, distinct from the cell’s own genetic material, and they multiply on their own. But in the process, mitochondria can accumulate small genetic mutations, which under normal circumstances are corrected by specialized repair systems within the cell. Over time, as we age, the number of mutations begins to outstrip the system’s ability to make repairs, and mitochondria start malfunctioning and dying.

Many scientists consider the loss of healthy mitochondria to be an important underlying cause of aging in mammals. As resident mitochondria falter, the cells they fuel wither or die. Muscles shrink, brain volume drops, hair falls out or loses its pigmentation, and soon enough we are, in appearance and beneath the surface, old.

The mice that Dr. Tarnopolsky and his colleagues used lacked the primary mitochondrial repair mechanism, so they developed malfunctioning mitochondria early in their lives, as early as 3 months of age, the human equivalent of age 20. By the time they reached 8 months, or their early 60s in human terms, the animals were extremely frail and decrepit, with spindly muscles, shrunken brains, enlarged hearts, shriveled gonads and patchy, graying fur. Listless, they barely moved around their cages. All were dead before reaching a year of age.

Except the mice that exercised.

Half of the mice were allowed to run on a wheel for 45 minutes three times a week, beginning at 3 months. These rodent runners were required to maintain a fairly brisk pace, Dr. Tarnopolsky said: “It was about like a person running a 50 or 55 minute 10K.” (A 10K race is 6.2 miles.) The mice continued this regimen for five months.

At 8 months, when their sedentary lab mates were bald, frail and dying, the running rats remained youthful. They had full pelts of dark fur, no salt-and-pepper shadings. They also had maintained almost all of their muscle mass and brain volume. Their gonads were normal, as were their hearts. They could balance on narrow rods, the showoffs.

But perhaps most remarkable, although they still harbored the mutation that should have affected mitochondrial repair, they had more mitochondria over all and far fewer with mutations than the sedentary mice had. At 1 year, none of the exercising mice had died of natural causes. (Some were sacrificed to compare their cellular health to that of the unexercised mice, all of whom were, by that age, dead.)

The researchers were surprised by the magnitude of the impact that exercise had on the animals’ aging process, Dr. Tarnopolsky said. He and his colleagues had expected to find that exercise would affect mitochondrial health in muscles, including the heart, since past research had shown a connection. They had not expected that it would affect every tissue and bodily system studied.

Other studies, including a number from Dr. Tarnopolsky’s own lab,  have also found that exercise affects the course of aging, but none has shown such a comprehensive effect. And precisely how exercise alters the aging process remains unknown. In this experiment, running resulted in an upsurge in the rodents’ production of a protein known as PGC-1alpha, which regulates genes involved in metabolism and energy creation, including mitochondrial function.

Exercise also sparked the repair of malfunctioning mitochondria through a mechanism outside the known repair pathway; in these mutant mice, that pathway didn’t exist, but their mitochondria were nonetheless being repaired.

Dr. Tarnopolsky is currently overseeing a number of experiments that he expects will help to elucidate the specific physiological mechanisms. But for now, he said, the lesson of his experiment and dozens like it is unambiguous. “Exercise alters the course of aging,” he said.

Although in this experiment, the activity was aerobic and strenuous, Dr. Tarnopolsky is not convinced that either is absolutely necessary for benefits. Studies of older humans have shown that weightlifting can improve mitochondrial health, he said, as can moderate endurance exercise. Although there is probably a threshold amount of exercise that is necessary to affect physiological aging, Dr. Tarnopolsky said, “anything is better than nothing.” If you haven’t been active in the past, he continued, start walking five minutes a day, then begin to increase your activity level.

The potential benefits have attractions even for the young. While Dr. Tarnopolsky, a lifelong athlete, noted with satisfaction that active, aged mice kept their hair, his younger graduate students were far more interested in the animals’ robust gonads. Their testicles and ovaries hadn’t shrunk, unlike those of sedentary elderly mice.

Dr. Tarnopolsky’s students were impressed. “I think they all exercise now,” he said.

After reading a study like this, I always think if they could put exercise in a pill form and sell it, the pill would cost a fortune, due to the benefits it offers. But exercise does not cost anything except our time and energy. Not a bad deal!

Gretchen Reynolds from the New York Times wrote, several Sunday’s ago, an interesting article about how scientists are looking at how exercise can make the brain more stress-resistant ( http://well.blogs.nytimes.com/2009/11/18/phys-ed-why-exercise-makes-yo u-less-anxious/ ). Researchers at Princeton University recently made a remarkable discovery that some of the neurons in rats that exercise respond differently to stress than the neurons of slothful rats.

Scientists have known for some time that exercise stimulates the creation of new brain cells (neurons) but not how, precisely, these neurons might be functionally different from other brain cells. Presented a few months ago at the annual meeting of the Society for Neuroscience in Chicago( http://www.sfn.org/am2009/ ) the researchers at Princeton University revealed their preliminary results of their remarkable discovery about the brains of rats that exercise.

In the experiment, scientists allowed one group of rats to run. Another set of rodents were not allowed to exercise. Then all of the rats swam in cold water, which they don’t like to do. Afterward, the scientists examined the animals’ brains. They found that the stress of the swimming activated neurons in all of the animals’ brains. But the youngest brain cells in the running rats, the cells that the scientists assumed were created by running, were less likely to express the genes. They generally remained quiet. The “cells born from running,” the researchers concluded, appeared to have been “specifically buffered from exposure to a stressful experience.” The rats had created, through running, a brain that seemed biochemically, molecularly, calm.

We all know that exercise is good for us, but we are now discovering how exercise helps us in different ways on a molecular level. Thanks now to improved research techniques and a growing understanding of the biochemistry and genetics, scientists are beginning to find out how exercise remodels the brain, making it more stress-resistant.

The stress-reducing changes wrought by exercise on the brain don’t happen overnight. However, as virtually every researcher agrees. In the University of Colorado experiments, for instance, rats that ran for only three weeks did not show much reduction in stress-induced anxiety, but those that ran for at least six weeks did. “Something happened between three and six weeks.” Says Benjamin Greenwood, Ph.D., a research associate in the Department of Integrative Physiology at the University of Colorado, who helped conduct the experiments( http://www.ncbi.nlm.nih.gov/pubmed/18300002 ).  “It’s not clear how that translates” into an exercise prescription for humans. We may require more weeks of working out, or maybe less. And no one has yet studied how intense the exercise needs to be. But the lesson is “don’t quit,’ Greenwood says. Keep running, cycling or swimming. You may not feel a magical reduction of stress after your first jog, if you haven’t been exercising. But the molecular, biochemical changes will begin, Greenwood says, and eventually they become, he says, “profound.”

Here at oomphTV we strongly recommend any kind of exercise program to help give you both “oomph” and calmness in your life. Consider this study in the beginning of 2010 and take a look at the 94-year old runner Jack Kirk video for inspiration http://www.oomphtv.com/people-with-oomph-features-short-videos-of-peop le-over-forty-redefining-age/jack-kirk-the-dipsea-demon After reading this blogpost and viewing the video, create your own exercise program and don’t let it be just another New Year’s resolution. Happy New Year and best of luck! Please feel free to comment, we look forward to hearing from you in 2010.

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