Wednesday, May 31, 2006

How does exercise affect insulin insensitivity?

Can you explain why a study from The University of Sherbrooke in Canada showed that exercising three times a week improved insulin sensitivity in younger women but not in older women? (European Journal of Applied Physiology, October 2005) Insulin sensitivity measures the ability of your cells to respond to insulin. When cells fail to respond adequately to insulin, blood sugar levels rise too high, and you are more likely to suffer diabetes, obesity particularly in the abdomen, high blood pressure, heart attacks, strokes and nerve damage. Inability to respond to insulin is the most common cause of diabetes in North America. Exercise helps your cells respond to insulin because exercise empties muscles of their stored sugar. Empty muscles can absorb sugar from the bloodstream whenever you eat and prevent blood sugar levels from rising too high.

Thirty-five percent of adults in North America will become diabetic because they eat too much and exercise too little, because being fat fills your fat cells with fat, which blocks insulin receptors and prevents your body from responding to insulin. Insulin prevents your blood sugar from rising too high, particularly after you eat. So when your cells do not respond adequately to insulin, your pancreas produces very large amounts of insulin, which constricts coronary arteries to increase your chances of suffering a heart attack, stimulates your brain to make you hungry and causes fat to be deposited in your belly.

The only places that you can store extra sugar in your body are in your liver and muscles. When you eat, sugar passes from your intestines, into your bloodstream, and then into your muscles and liver. When your muscles are full of sugar, sugar can only enter your liver, and your blood levels rise too high. This causes sugar to stick to cells. Once stuck on a cell, sugar is converted to sorbitol which damages the cells to cause blindness, heart attacks, strokes, kidney damage and all the other side effects of diabetes. This study showed that younger women could exercise intensely enough to empty their muscles on a regimen of three times a week, but older women could not. So most older people need to exercise every day to deplete their muscles of stored sugar. Younger people can exercise less frequently and to get the same results, as long as they exercise very vigorously during their three sessions per week.

Tuesday, May 30, 2006

Does Viagra cause heart attacks?

At the 2006 American College of Cardiology meeting, doctors from Italy reported that Viagra may actually help prevent heart attacks in diabetics. After one week of taking Viagra daily, diabetics had significantly increased blood flow to their hearts and a marked reduction in C- reactive protein, a marker for inflammation, a leading cause of heart attacks. No data show that Viagra causes heart attacks and much data show that Viagra may prevent them.

Why then are there so many lawsuits from people who claim that they suffered heart attacks when they took Viagra? Because the heart attack victims claim that the doctor should not have prescribed Viagra to people who have weak hearts that cannot withstand the stress of making love. The rapid heart rate associated with excitement is due to stress hormones, not the markedly increased circulation of blood associated with vigorous activity.

Monday, May 29, 2006

Will electric muscle stimulators cause you to lose weight?

No. The US Federal Trade Commission ordered the makers of belts that send an electrical impulse into the belly muscles must stop advertising that the devices build muscle and get rid of fat. The manufacturers have agreed to stop promoting these devices as a weight-loss and muscle-building tool. They had spent $12 million on half-hour television spots, to make their ad one of the most aired infomercials in the country.

Muscles contract when your brain sends an electrical impulse down nerves. Muscles also contract when an electric wire sends electrical impulses over muscles. However, there is no data to show that the contractions caused by electrical impulses will enlarge muscles or get rid of fat the way that exercise does.

Friday, May 26, 2006

Does bicycling cause impotence?

The greatest source of discomfort for cyclists is the nose of their bike seat pressing on nerves and soft tissues. For men, this pain brings the additional worry of impotence. Impotence is caused by nerve and artery damage. Exercising regularly helps to keep arteries healthy, so bicycling helps prevent impotence, as long as it does not damage the local arteries and nerves. Recent studies show that three percent of regular male bicycle riders become impotent, and virtually all of them felt pain or numbness before the problem occurred. When a nerve is pinched or the blood supply is shut off to the penis, a man feels numb. Men who ride with conventional bicycle seats and do not feel numb are not likely to be at risk. If you feel no discomfort when you ride, keep on riding and stop worrying. If you feel numbness, get a new seat.

Half of the penis is inside the body and the main blood supply comes from the area just behind the scrotum and in front of the rectum. So bicycle seats that press on that area can cause impotence, while those that do not have a nose and have a widened area to hold your weight on your sitz bones should prevent the problem. Some entrepreneurs developed seats that have holes in the middle. Their theory is that if there is no pressure behind the scrotum, there will be no numbness. However, no good studies show that these seats prevent numbness and therefore prevent impotence, because the nose in front of the hole still exerts pressure on the nerves and arteries. They may make the problem worse because the pressure on an area increases as an area deceases. Making a hole in the middle decreases the surface area of the saddle and therefore increases the pressure on the arteries and nerves.

The best way to avoid pressure on the arteries that carry blood to the penis is to use a saddle without any nose. I use a rectangular-shaped seat with rounded edges in the front, called The Seat by Ergo. Similar designs are available from The Solution Bicycle Seat, Easyseat, Spongywonder and Spiderflex brands. The Seat is wide enough to allow me to put my weight on the sitz bones of my pelvis instead of my crotch. I never suffer numbness and don't worry about impotence, but it doesn't work for everyone. Racers need to have a bicycle seat nose between their legs to help control the bicycle with their legs, but if you have no need to ride with both hands off the handle bars at the same time, you should be able to use a noseless seat. Noseless seats force you to bend forward. To keep yourself from falling, you have to hold yourself up on your handlebars. This puts a lot of pressure on your shoulders arms and hands, so you must strengthen your upper body and change positions often.

Other tips for comfort in a bicycle seat include: 1) Avoid seats with excessive padding. The greater the padding, the deeper you sink into the saddle and the more likely you are to feel numbness. 2) Use gel saddles. They are not too hard and not too soft. 3) Never tilt the saddle nose upward. The seat should be level or angle downward slightly. 4) Set your handlebars higher so that you do not have to bend forward. The lower you bend, the greater the pressure on your perineum. 5) Ride a more upright position. However, this increases wind resistance and will slow you down. 6) Change positions often as you ride. 7) Wear thin padding in your pants. Most good bicycle pants come with form-fitted chamois padding.

Thursday, May 25, 2006

What causes muscle fatigue in endurance events?

When you exercise for a long time, your muscles start to burn and feel sore, which forces you to slow down. You call this fatigue and tiredness, but a recent study from Japan shows that muscle fatigue is caused by damage to the muscle itself (Medicine & Science in Sports & Exercise, July 2005). This also explains why exercising long and hard enough to feel the burn for an extended period leaves your muscles sore for one or more days afterwards. Athletes call this Delayed-Onset Muscle Soreness (DOMS) and they learn that they have to have this next-day soreness to improve for competition.

Running is much more fatiguing than cycling. When you run, your heel hits the ground and stops your leg from moving. This sudden stopping with each foot strike stretches your contracting muscles and tears them to cause a lot of muscle damage. It’s called eccentric contractions of muscle and occurs with far less force in cycling. You pedal with a smooth rotary motion and do not stop suddenly. The eccentric contractions during running cause a high degree of muscle injuries, limit how far person can run fast, and require far more rest days or easy days than cyclists use in their training programs.

Since muscle fatigue during endurance competitions is caused by muscle damage, anything that strengthens muscles will improve performance in endurance events. The only way to make a muscle stronger is to damage the muscle with hard exercise, feel sore on the next day, exercise more easily on as many days as it takes for the soreness to go away, and then exercise vigorously again. Athletes in competitive sports must exercise at a reduced intensity on the days that their muscles feel sore. This makes muscles more fibrous and resistant to injury so that muscles can withstand greater forces when athletes exercise on their hard days.

Wednesday, May 24, 2006

My back hurts; can I still run?

People with back pain need to exercise as much as everyone else, but running is usually a poor choice of activity. The bones of your spine are located one on top of the other, separated by pads called discs. Bones are much harder than discs, so when spinal bones are compressed and move closer together, they can flatten the discs like pancakes. Since the discs are then shorter, they have to go somewhere else, so they widen and press on the nerves near them, causing pain. This is called a herniated disc. Anything that presses the bones closer together squashes the disc further and usually makes it hurt more. During running, the force of the foot striking the ground is transmitted up the leg to the back, which can compress the discs and cause pain.

The best sports for people with back pain are those that do not hurt when you do them. Riding a bicycle, walking slowly and swimming do not exert a jarring force on the discs to compress them, so these exercises are recommended for people with back pain as long they don’t hurt while they exercise. Doctors often recommend special exercises to flatten the lower back, strengthen the belly muscles and stretch the lower back muscles. The key to exercising when you have a compressed disc is to stop exercising when you feel pain. You may need to try several different activities to find the right one for you.

Tuesday, May 23, 2006

Starting a new exercise program

If you’d like to start a new exercise program, pick any sport or activity that uses continuous motion (such as running, fast walking, cycling, swimming, skating, rowing, dancing) that you think you might enjoy. Start out at a relaxed pace until your muscles feel heavy and then stop. For the first several days or weeks you may be able to exercise only for a few minutes. Increase the amount of time gradually until you can exercise 30 minutes a day at a relaxed pace and not feel sore. Take a day off or go very easy any time you have any muscle soreness.

If you're happy with this program, you don't need to go any further. However, if you want to improve, follow the training methods that competitive athletes use. When a 30-minute session is easy for you, you are ready to begin training for fitness. Try to increase the intensity of your exercise on one day a week. Do your jogging, cycling or whatever you have chosen as your sport at a slow pace to warm up. Then gradually increase the pace until you start to feel short of breath and your muscles start to feel sore, and then slow down. Then when you recover, pick up the pace again. Repeat these surges until your muscles start to stiffen and then quit for the day. Take the next day off and go easy the rest of the week. Then once a week, keep on making your one-day-a-week hard workout harder and harder. You will be continuously increasing your level of fitness.

Before you start any new exercise program, check with your doctor to make sure that you do not have anything wrong with your heart or blood vessels. Intense exercise won’t hurt a healthy heart, but it can increase your risk for a heart attack if you already have a damaged heart.

Monday, May 22, 2006

Do muscles turn into fat if you stop lifting weights?

Muscles can't possibly turn to fat. When you exercise, your muscles become larger and stronger because exercise causes extra protein building blocks, called amino acids, to deposit in muscles. All day long, amino acids pass from your muscles into your bloodstream and then back into muscles. Exercise is the major stimulus to force amino acids back into muscles.

When you stop exercising, fewer amino acids go into your muscles so the muscles get smaller. Your body has no way to store extra protein, so amino acids that are not used in your muscles are picked up by your liver, which uses them for energy or converts them into fat for storage. So if you stop exercising, you have to eat less or you will gain weight. But muscles never turn into fat.

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Sunday, May 21, 2006

How does exercise prevent diabetes?

An exciting study from Yale shows that intense exercise is far more effective in preventing and controlling diabetes than exercising at a leisurely pace (Journal of Applied Physiology, January 2006). Inactive, healthy, non-obese women over 72 years of age were started in training programs of hard (80 percent of aerobic capacity), moderate (65 percent) and easy (50 percent). All three groups did the same amount of work, burning 300 calories per session. The intense group had a great improvement in their ability to use sugar and suppress fat formation, while the low intensity group had little benefit.

This means that intense exercise can help both to prevent and to treat diabetes. The most tissue damage occurs immediately after eating, when blood sugar levels rise the highest. After you eat, sugar goes from the intestines into the bloodstream. The only places that sugar can be stored are in your muscles and liver. When your muscles are not exercised, they are full of sugar and sugar has no place to go after it enters your bloodstream. On the other hand, when your muscles are exercised, they empty their stored sugar. Then when you eat, sugar can go from the intestines into the bloodstream and then immediately into the muscles, preventing a high rise in blood sugar.

The exciting news from this study is that the more intensely you exercise, the greater the protection from developing diabetes and the better the control of your diabetes if you already have it. A word of caution: 75 percent of diabetics die from heart disease and some people can suffer heart attacks during intense exercise, so check with your doctor first.

Saturday, May 20, 2006

Does television cause obesity?

A study from Harvard School of Public Health shows that the longer women watch television, the more likely they are to become obese and develop diabetes (Journal of the American Medical Association, April 9, 2003). Lack of exercise is a strong risk factor for obesity, high blood pressure, heart disease, some types of cancer, and diabetes.

The Nurses' Health Study followed more than 50,000 women for six years, and in that time 1,500 of the women became diabetic. Those who watched the most television doubled their risk for developing diabetes. Even light activity was associated with substantially lower risk.

In this study, the women watched television from zero to more than 40 hours a week, and those who watched the most TV didn't have time to do much of anything else. People who are addicted to television should have a stationary bicycle or some other piece of exercise equipment in front of every set so they can exercise whenever they watch TV.

Friday, May 19, 2006

Why are diabetics at such high risk for heart attacks?

A recent study from Washington University in St Louis may explain why more than 75 percent of diabetics die of heart disease (Journal for the American College of Cardiology, February 7, 2006). The heart muscle of diabetics uses a much higher percentage of fat for energy than that of non-diabetics, to markedly increase risk for heart attacks.

The energy source for heart muscle is mostly sugar and fat, and to a lesser degree, protein. Muscles need far more oxygen to process fat than to process sugar. The blood supply to heart muscle comes from large arteries on the outside of the heart. Diabetics have narrowed arteries because high blood sugar levels cause plaques to form and reduce the diameter of the coronary arteries. The increased need for blood flow from burning fat and the decreased blood flow from narrowed arteries put diabetics at very high risk for heart attacks, heart failure and sudden death. The increased use of oxygen increases blood levels of oxidants that further damage the inner linings of arteries.

Type 2 diabetes can be prevented
If you are already diabetic, please read Treatment of insulin resistance

Thursday, May 18, 2006

Are irregular menstrual periods in an athlete a concern?

Not getting enough calories can cause lack of periods or irregular periods, and this is common in sports that emphasize weight control such as gymnastics or diving.
However, Swedish researchers showed that irregular periods in female athletes are usually caused by high levels of male hormones, rather than just by not eating enough food (Fertility and Sterility, Volume 79, Issue 4, 2003). The researchers found that many female athletes who have irregular periods have much higher blood levels of masculinizing hormones than those with regular periods.

Female athletes with irregular periods and high male hormone levels usually also have larger muscles and bones, and are stronger than the athletes with regular periods. This study suggests that women who have high blood levels of male hormones are more likely to become athletes and the masculinizing hormones that make them better athlete are also likely to cause irregular periods. See my report on Polycycstic Ovary Syndrome (PCOS), and check with your doctor or a gynecologist.

Wednesday, May 17, 2006

How reliable are the health claims on food labels?

The U.S. Food and Drug Administration has loosened restrictions on how much scientific proof is required before possible health benefits appear on food labels. For example, the FDA now allows sellers of certain nuts to claim that "Scientific evidence suggests, but does not prove, that eating 1.5 ounces per day of some nuts, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease." Sellers of seafood that is rich in omega-3 fatty acids will want to claim that their products prevent heart attacks, and so forth, so we will probably see a proliferation of these statements on food labels in the years ahead.

A manufacturer cannot claim that a product prevents heart attacks just because it contains nuts. For example, putting nuts in ice cream will not allow a manufacturer to claim that ice cream with nuts prevents heart attacks. The claims are supposed to help you understand that the specific food only helps to prevent heart attacks when a person does not take in too many calories, does not eat too much saturated and partially hydrogenated fats, and does eat lots of vegetables and other foods derived from plants. You cannot say that eating nuts prevents heart attacks, but you can say that eating nuts as part of a healthful diet helps to prevent heart attacks.

Tuesday, May 16, 2006

Do fat-blocker products work?

Most of the so-called "fat blocker" products are derived from chitin, a polysaccharide found in the exoskeleton of shellfish such as shrimp, lobster, and or crabs. The sellers claim that chitin causes weight loss by binding fats in the stomach and preventing them from being digested and absorbed. Some call their products "fat magnets" or "fat trappers." Researchers at the University of California-Davis demonstrated that chitin fat blocker products do not significantly block absorption of dietary fat (Obesity Research, Volume 11, 2003). At least three other studies have reached the same conclusion.

The UC study involved 15 men who consumed five meals per day for 12 days, with a total of about 25 grams of fat per meal. The amount of fat excreted during four days when they took fat-blocker capsules was then compared to the amount excreted during days without them. Taking 10 capsules of the product per day increased fecal fat excretion by only about one gram (a gram of fat is nine calories). This would have no significant effect on a person's weight. The biggest loss is to your wallet; some of the products I checked would cost about $35 to block the amount of fat found in a Big Mac.

Other diet gimmicks

Monday, May 15, 2006

Why do sled dogs have so much more endurance than humans?

How can sled dogs run more than 100 miles a day for weeks on end, while humans couldn’t possibly recover from such abuse of their muscles? A study from Ohio State University shows why (Medicine & Science in Sports & Exercise, August 2005). How long you can exercise a muscle depends on how long you can keep stored sugar, called glycogen, inside that muscle. Muscles burn carbohydrates, fats and protein for energy during exercise. They get these sources from both the bloodstream and from the muscles themselves. However, when a muscle runs out of its stored sugar, it hurts, becomes more difficult to coordinate and requires far more oxygen than usual. So a limiting factor in how long you can exercise a muscle is how much sugar you can store in a muscle, how quickly you use it up, and how quickly you can restore sugar the sugar in your muscles.

Humans take a long time to restore muscle glycogen. Top marathon runners restore muscle glycogen in anywhere from a day to several days. This study shows that sled dogs can restore muscle glycogen almost as quickly as they are fed. They were able to restore more than 50 percent of their resting muscle glycogen after two consecutive 100-mile runs even when fed a low-carbohydrate, high-fat diet. Humans could never replace muscle glycogen that fast.

The only way that you can teach your muscles to store more glycogen and preserve it better is to train by running (or cycling or swimming) lots of miles and doing long depletion runs taking more than three hours at least once a week. Doing too many depletion runs will delay recovery of muscle glycogen so that you will not be able to do the very fast short interval runs that teach your brain and muscles how to run faster.

Note: It has been brought to my attention that this article may be used to support abusive dog sledding practices. My intent was to provide useful information about human muscles and human training techniques. I have no expertise in dog racing or veterinary medicine.

Sunday, May 14, 2006

Is calcium deficiency the most common cause of osteoporosis?

Vitamin D deficiency may be even more important; a study from Amsterdam shows that 64 percent of postmenopausal women with osteoporosis lack vitamin D. A woman's bones are strongest when she is 20; you lose bone continuously over your lifetime until at 90, virtually all women have osteoporosis. Only recently have doctors become aware of this high rate of vitamin D deficiency which weakens bones. Very few people meet their needs for vitamin D from food; the most important source is sunlight. Still, during summer when sunlight is abundant, the prevalence of vitamin D deficiency was 59 percent; during winter it was 69 percent. Warnings about skin cancers from sunlight exposure may have increased risk for osteoporosis.

This study, presented at the 2005 annual meeting of the American Society for Bone and Mineral Research, shows that postmenopausal women should get blood tests for vitamin D, and those with low levels should get more sunlight or take vitamin D supplements. Neither calcium nor vitamin D supplements are effective as treatments for osteoporosis; check with your doctor about the bone-strengthening medications

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Saturday, May 13, 2006

Will bed rest help me get better faster when I'm sick?

A huge review of the medical literature showed that there is no evidence that bed rest helps you to heal faster from any medical condition. During World War II, American soldiers were drafted and sent to do their basic training at the Great Lakes Naval Training Center. A major epidemic of flu occurred affecting almost all the troops. Half of the soldiers were kept in bed, while the other half stayed in the vigorous exercise of basic training. Both groups required the same amount of time to recover, although those forced to undergo the rigorous demands of basic training complained more.

Researchers at the University of Queensland in Australia searched the medical literature from 1966 to 1999 and found only 39 studies testing whether bed rest benefits any medical condition. Twenty-four studies showed that bed rest was of little or no benefit in preventing side effects of medical procedures such as spinal anesthesia, spinal fluid withdrawal, and multiple x ray procedures. Fifteen studies showed no benefit in treating medical conditions such as low back pain, spontaneous labor, high blood pressure during pregnancy, uncomplicated heart attacks, rheumatoid arthritis or infectious hepatitis. So the next time you feel sick, stay in bed if you like, but it probably won't help you recover faster.

Friday, May 12, 2006

Will I recover faster from a very hard workout or a very long one?

You train for competitive sports by taking a hard workout, which makes your muscles sore for the next day or two and then when your muscles feel fresh again, you take another hard workout. Every intense workout causes muscle damage and soreness. Biopsies taken on the day after a hard workout from the muscles of athletes show bleeding into the muscles and disruption of the muscle fibers. If you try to exercise intensely when your muscles are still sore from a previous workout, you are at great risk for injuring yourself. Regular exercisers and competitive athletes improve most with a weekly schedule that includes one or two intense workouts and one longer session for endurance. To prevent injury, they follow each of these three harder workouts with easy workouts or days off.

Intense workouts cause far more muscle damage than longer endurance workouts. That means that an athlete can exercise harder on the day after an endurance workout than the day after an intense one. So weightlifters should not lift weights with the same muscle groups on the day after the one day a week that they lift very heavy weights. Runners should run very slowly on the days after the two days a week that they run very fast. Most training programs include two intense workouts, say Tuesday and Friday, followed by days of very easy workouts on Wednesday and Saturday and a longer workout on Sunday followed by a moderate workout on Monday.

Thursday, May 11, 2006

Will blood pressure drugs interfere with my exercise program?

The beta blocker drugs used to treat blood pressure and heart problems can markedly impair your ability to exercise, according to a study from Switzerland (European Journal of Applied Physiology, October 2005). How hard you can exercise is limited by the ability of your heart to pump blood from your lungs to your exercising muscles. Beta blockers markedly reduce blood flow and oxygen supply to muscles. Beta blocker brand names include Toprol, Inderal, Blocadron, Coreg, Inopran, Levatol, Pindolol, Sectral, Tenormin, Timolol Trandate, Zebeta and Bisoprol.

Beta blockers are prescribed to treat people who have had heart attacks, heart pain, heart failure, rapid heart beat and atrial fibrillation. However, even though many physicians prescribe beta blockers to treat high blood pressure, there is no data show that they prevent heart attacks in healthy people. If beta blockers interfere with your ability to exercise, ask your doctor if you can take other types of medications such ace inhibitors, angiotensin receptor blockers or calcium channel blockers. Better yet, control your blood pressure with diet.

Wednesday, May 10, 2006

How can I run faster?

You cannot run faster by consciously trying to increase your stride length. When you try to take longer strides that feel unnatural, you lose energy and run more slowly. Your most efficient stride length is determined by what feels most comfortable to you.

Your heel hits the ground with great force. The tendons in your legs absorb some of this energy and then contract forcibly after your heel hits the ground so you regain about 60 to 75 percent of that stored energy. When you try to take a stride that is longer than your natural one, you lose a great deal of this stored energy, tire much earlier and move your legs at a slower rate.

When most athletes run as fast as they can, they run at close to the same stride rate. For example, a video at the New York City Marathon showed that the top 150 runners had the same cadence, taking 92 to 94 steps a minute. The difference between the top runners and the others is that the best runners took longer strides. The key to running faster in races is to make your leg muscles stronger so you can contract them with greater force so they drive you forward with a longer stride. Competitive runners strengthen their legs by running very fast in practice two or three times a week and by running up and down hills once or twice a week.

Tuesday, May 09, 2006

Are cortisone injections into joints safe?

Doctors often inject cortisone-type medications into painful damaged joints and tendons. Single injections can relieve pain and swelling and appear to be safe, but many studies show that repeated injections can damage joints and delay healing. Most doctors will recommend having no more than three injections into the same joint in a lifetime.

Athletes and exercisers often experience pain from injuries to their tendons, muscles, fascia or ligaments. When an injury heals in a few days, no treatment is indicated, but sometimes they persist for months, particularly in the fascia on the bottom or back of the heel, in the large tendon in the back of the lower leg, or in the tendons on the elbows or shoulders. Cortisone-type drugs reduce swelling and lessen pain and can allow an athlete or exerciser to get back to sports, but cortisone injections can weaken the tendons for several months.

If you suffer pain in tendons, muscles, ligaments or fascia, check with your doctor to see if you have a treatable chronic disease causing it, such as hepatitis or reactive arthritis. Non-steroidals that are usually prescribed can help to block pain but do not heal damaged tissue. If you receive a cortisone injection, make sure that you protect that area from hard exercise for at least two months.

Monday, May 08, 2006

How does exercise protect against memory loss?

Nobody really knows how exercise helps prevent loss of mental function, but every factor that helps protect you from getting a heart attack or stroke also protects you from dementia. Anything that protects blood vessels also protects your brain. Heart attacks and dementia are associated with eating too much fat, saturated fat, fried foods, refined carbohydrates, too many calories, and not eating enough vegetables, nuts, beans and other seeds; being overweight, not exercising, taking more than two alcoholic drinks a day, and smoking. More on dementia

The Nurses' Health Study from the Harvard School of Public Health shows that exercising your muscles improved cognitive function in older women (JAMA, September 2004). Another study shows that more than 85 percent of middle-aged people who start an exercise program drop out in the first six weeks. You're more likely to continue if you exercise with others: a spouse or friend, with a personal trainer, or in an organized group or class.

Sunday, May 07, 2006

How old should a child be to start serious athletic training?

Young children can start training for athletic competition at a very young age as far as their bodies are concerned, but they should not start before they want to accept the regimented lifestyle required for athletic competition. In 1967, I started competitive long distance running for young children and was the first national chairman of the age group committee of the Amateur Athletic Union and The Road Runners Club of America. Children came from all over the United States and Canada to compete in age group cross country and track running. Many were coached by experienced runners and trained with the same types of workouts used by older, more experienced runners. These children rarely suffered from injuries and when they were injured, they recovered faster than older runners do.

Young children are not at increased risk for injuries when they run races or lift weights. Doctors expressed concern that the growth centers in their bones would be more likely to break, but this rarely happens. However, many of the better runners quit. In one study from Southern California, 90 percent of female runners under age nine stopped running before they reached high school. It's all right for young children to start training in a sport, provided that they want to do it, that they take plenty of days off from training, and that their coaches and parents allow them to be children.

Saturday, May 06, 2006

Should I load up on carbs before a big race?

A pasta supper before a race is traditional because athletes believe that carbohydrate loading is the best way to prepare their muscles. A study from the University of Texas showed that taking foods with both carbohydrates and proteins increases an athlete’s endurance more than eating just carbohydrates (International Journal of Sport Nutrition and Exercise Metabolism, Volume 13, Issue 3, 2003).

When you exercise vigorously for more than two hours, you need to take extra fluid, salt and calories. The best way to do this is to drink whatever fluid tastes best to you, and eat any food that includes plenty of salt. Many studies show that taking in extra carbohydrates during an event prolongs endurance, so athletes often eat oranges and other fruits, cookies, sandwiches and any other carbohydrate-rich food that they like. This study shows that they will have even greater endurance if they also take in high-protein food such as cheese, meat, chicken or fish. During prolonged, intense exercise, your muscles are damaged and the extra protein supplies protein building blocks called amino acids that can help to limit muscle breakdown and hasten recovery.

Thursday, May 04, 2006

Should I drink water when I exercise, or not?

When you exercise hard or in hot weather, you sweat and breathe off huge amounts of fluid. Losing fluid reduces blood volume to make you tired. Anyone who exercises vigorously can increase their endurance by taking in fluids, and competitive athletes can increase their endurance by taking in extra fluids just before the start of their event and drinking fluids regularly during events that last more than an hour. Be sure to replace salt as well as fluid you lose when you sweat. Don’t force yourself to drink large amounts of water.

A study presented at the Experimental Biology meeting in San Diego (April 11-15, 2003) demonstrated that drinking water helps athletes to exercise longer. Ten college students drank four, eight or 12 eight-ounce glasses of water per day for 12 weeks. On four glasses of water per day, they had five percent lower blood volume than on eight glasses, and ten percent lower that on 12 glasses. Lowered blood volume should not effect non-exercisers, but regular exercisers can increase their endurance by drinking more fluids.

More on how much water you need

More on hyponatremia (too much water)

Wednesday, May 03, 2006

The perfect fitness vacation!

Imagine a vacation where a 5-star hotel travels to meet you at the end of every day's touring. Where you eat like a king (or queen) and don't feel the least bit guilty because you're cycling enough to burn off all the calories. Where you can soak up the musical history of the region that spawned the blues, rock and roll, gospel, dixieland, Cajun and country -- with live performances twice a day. Santana Tandems made this dream vacation a reality, and for us it was the trip of a lifetime.

With 75 other couples, we boarded the Delta Queen in Memphis and traveled down the Mississippi to New Orleans. Each day we cycled 30-70 miles, then re-boarded the boat downriver. We toured beautiful plantation homes and charming Southern towns; and, for contrast, we were the only bicycle group ever allowed through the 18,000-acre grounds of Angola State Penitentary. Our final day was spent on an eye-opening tour of the devastation and rebuilding in New Orleans. We were the FIRST large tour group to visit the city since Katrina. New Orleans needs tourists to survive, so if you have a chance to go there, please do! The musicians are playing; they'd like an audience again.

We'll be back on the Delta Queen next year, in April 2007! The Santana Tandems website has full details on this tour and the many other wonderful cycling vacations they conduct.

More pictures of our trip

Tuesday, May 02, 2006

How can I improve my coordination?

Everyone from chess and violin players to dancers and professional athletes can benefit from training to become stronger. Lifting weights to develop large strong muscles can improve coordination, make you faster and more flexible as well as stronger. It will not interfere with the coordination that you need for such fine muscle movements as playing the piano or shooting a basketball.

Muscles are made up of two different types of fibers. The red, slow-twitch fibers are used for endurance and the white, fast-twitch fibers are used for strength and speed. When you strengthen a muscle, you train the same fibers that also make you faster, so strength training helps you to move faster. Coordination is controlled by the ability of your brain to direct the more than 500 muscles in your body. Strengthening a muscle does not hinder brain control of muscles. Stronger muscles use fewer fibers for the same task and therefore are easier to control.

Full length, range-of-motion strength training can also improve flexibility. To make a muscle more flexible, you need to stretch it. When you lift a heavy weight, your muscles stretch before the weight starts to move. In addition to making you a better athlete, strength training will also help you in everyday activities, such as opening stuck doors, jars and faucets; and doing your household chores.

Monday, May 01, 2006

Should I throw away my Teflon pans to avoid PFOA poisoning?

PFOA (perfluorooctanoic acid, a suspected carcinogen) is used to manufacture Teflon, but there is none present in the finished products. While the US Environmental Protection Agency (EPA) is rightfully concerned about PFOA in the environment, you can continue to use your Teflon-lined pans without fear.

However, non-stick pans may release other toxic particles if they are used at very high heats, so they are not appropriate for deep-fat frying, broiling, grilling or similar high- temperature cooking methods. I recommend avoiding this type of cooking anyway, because high heat and browning can form carcinogens in foods regardless of the type of cookware you use. Diana’s recipes are almost all prepared in ordinary cooking pots or bowls, and do not require browning, so you don’t need to worry about foods sticking to your pots.