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Exercise Makes You Smarter

People who exercise regularly are far less likely to suffer dementia and had less than half the risk of death during the 17-year study period, compared to those who do not exercise (Medicine & Science in Sports & Exercise, February, 2012).

Researchers followed 45,000 men and 15,000 women, ages 20 to 88 years, in the United States for an average of 17 years. Six times as many people in the low fitness group suffered from dementia, compared to those who exercised regularly. While deaths in the United States associated with heart disease, breast cancer and stroke have declined in recent years, deaths related to dementia and Alzheimer's disease rose 46 percent between 2002 and 2006.

Another exciting study, from Japan, shows that many of the benefits that exercise provides to muscles are also provided to your brain (The Journal of Physiology, February, 2012;590(Pt 3):607-16).

THE STUDY: Adult male rats exercised to exhaustion at moderate intensity on a treadmill. Glycogen, sugar stored in muscles, was depleted by 82-90 percent. One day later, the rats' muscles could store 43-46 percent more than they could originally, In a like manner, brain glycogen levels decreased by 50-64 percent with exhaustive exercise, and were able to store 29-63 percent more on the next day. The greater the depletion of sugar in muscles and brain, the greater the ability to store more sugar after the rats were fed. The brain filled with sugar before the muscles did and after four weeks of training, the rats' brains could store significantly more glycogen.

EXPLANATION: Sugar is the most efficient source of energy for your muscles during intense exercise. Sugar is the most efficient source of energy for your brain ALL the time. When you exercise regularly, you increase the ability of your muscles to store sugar so you can move faster and longer. This study suggests that exercise also increases the energy supply to your brain, which will help you to think and reason better.


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Belly Cramps During Exercise

The most common cause of belly cramps during exercise is reduced blood flow to a full colon. To prevent this from happening to you, try to have your colon empty before you start to exercise.

Twelve athletes (cycling, long-distance running and triathlon) were referred to a gastroenterologist to evaluate debilitating cramps during exercise (Br J Sports Med 2011, published online 20 October 2011). Sophisticated tests showed that all had decreased blood flow to their intestines during maximal-intensity exercise and 50 percent had it during sub- maximal exercise.

BLOOD FLOW TO INTESTINES IS REDUCED: A review of the world's literature shows that during exercise, blood flow to muscles increases to very high levels, which reduces blood flow to the intestines. During intense exercise, it can be reduced by more than 80 percent (Alimentary Pharmacology & Therapeutics, March 2012; 35(5):516-28).

EXERCISE MAKES YOUR COLON CONTRACT: Intense exercise often causes giant contractions of your colon that move stool, gas and fluids toward the end of your colon. Your intestinal muscles then need extra blood to supply them with oxygen. However during intense exercise, blood flow to the intestines is reduced and the contracting intestinal muscles suffer from lack of oxygen, so they hurt.

EMPTY YOUR COLON: To prevent belly cramps, you should empty your colon prior to your most intense workouts and races.

• EAT A HIGH-FIBER DIET WITH LOTS OF FRUITS AND VEGETABLES. The extra fiber leaves a residue in your intestines that holds water that keeps the contents of the colon soft. This will make it easier for you to empty your colon before exercise.

• RESTRICT THE GREAT CONSTIPATORS - BREAD AND SPAGHETTI. Foods made from flour are usually low in fiber and bulk.

• TRY TO EMPTY YOUR COLON AFTER YOU HAVE HAD BREAKFAST. Food entering your stomach causes the gastro-colic reflex that causes your colon to contract and push stool toward its opening. Thus for many people, it is easier to go to the bathroom after breakfast.

• GET IN THE HABIT OF TRYING TO EMPTY YOUR COLON AT THE SAME TIME OF DAY EVERY DAY. After you eat, food passes to your stomach. Then the pyloric sphincter at the end of your stomach closes, and food is not allowed to pass into your intestines until it is turned into a liquid soup. Food can remain in your stomach for up to five hours. Then your stomach contracts and squeezes the liquid soup into your intestines. The liquid soup does not solidify until it reaches your colon, where large amounts of fluid are absorbed. The longer stool remains in your colon, the more fluid is absorbed and the harder it becomes, making it more difficult to pass. You want to get the soft stool out soon before it hardens.


Raynaud's Phenomenon

If your fingers turn white and start to hurt when you're out in the cold, you may have a condition called Raynaud's phenomenon.

MECHANISM: Normal skin temperature is about 90 degrees F. On exposing your fingers to cold, the blood vessels close, the skin turns white and skin temperature drops. When skin temperature reaches 59 degrees F, your brain tries to save your skin by opening the blood vessels and the skin turns red and starts to itch and burn. If you warm your hands at this point, your skin will not be damaged, but if you do not get out of the cold, the blood vessels in your hands will close again and the temperature in your hands can drop to freezing.

People who have Raynaud's phenomenon have blood vessels in their hands that do not open when the skin temperature reaches 59 degrees. Several diseases, smoking and using vibrating equipment can cause Raynaud's phenomenon.

PREVENTION: If you have Raynaud's phenomenon, wear two or more layers of gloves or mittens. When a skier's fingers feel cold, he is supposed to swing his arms very rapidly about his shoulder with a straight elbow. This will drive blood, like a centrifuge, into the fingers to warm them.

Inexpensive single-use hand warmer packets can keep you from being miserable when you want to stay outside. They are available in sporting goods stores, ski shops and online.

Blood pressure drugs called calcium channel blockers (Nifedipine) can help to treat and prevent Raynaud's phenomenon. Another option is nitroglycerin ointment, a prescription medication that is used to treat heart pain. When applied to the forearm, it opens blood vessels leading to the hands.

FROSTBITE: Frostbite means that your skin is frozen. You have plenty of warning before that happens. Get out of the cold when your skin temperature reaches 59 degrees F, and it turns red, and starts to itch, tingle and burn.

The most effective treatment for frostbite is to warm the skin in water set between 100 and 108 degrees Fahrenheit. Don't warm the frozen part if there is any chance that it will be frozen again. People who have suffered frostbite are more susceptible to a future cold injury.


Recipe of the Week:

Turkish Three-Bean Soup

You'll find lots of recipes and helpful tips in The Good Food Book - it's FREE


February 19th, 2012
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About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities. Read More
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