Leucine No Better than Carbs for Energy

A study from Australia showed that leucine helps athletes exercise longer (European Journal of Applied Physiology, August 2006), so now exercisers are lining up to waste their money on supplements that are no more effective than any other source of sugar.Leucine is a branched chain amino acid that the liver readily converts to sugar. Your body needs extra sugar during endurance exercise, and it doesn't care where it gets it. Your brain gets more than 95 percent of its energy from sugar in your bloodstream. It cannot store extra fuel in its cells. However, there is only enough sugar in your bloodstream to last three minutes. To prevent blood-sugar levels from dropping, your liver constantly releases sugar from its cells into your bloodstream....

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Belly Fat: Why it's More Dangerous than Hip Fat

If you store more fat in your belly than in your hips, your cells are likely to be resistant to insulin which puts you at high risk for high blood pressure, diabetes, heart attacks, strokes and premature death. In one recent study, researchers measured insulin resistance and compared it to several risk factors for diabetes in men and women: 1) heart-lung fitness; 2) whole-body fatness and 3) abdominal obesity (Diabetes Care, March 2006). They showed that lack of physical fitness and overweight are very significant predictors of diabetes in men and women and that the single most important measure of insulin resistance is storing fat in the belly rather than the hips.Storing fat in your belly causes you to store excess fat in your liver, which...

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Fat Restriction: Don't Limit the Good Fats

Almost 50,000 women in the Women's Health Initiative Dietary Modification Trial from Harvard Medical School were given dietary counseling to reduce their fat intake to less than 20 percent of their daily calories (Clinical Diabetes, July 2006). This intense dietary counseling did not reduce the incidence of heart attacks, strokes or cancers even though the women reduced their intake of fat by 8.2 percent.Data from the eight-year follow up show that it is difficult to reduce total fat intake, and that dietary counseling to reduce total fat intake does not reduce the risk of heart attacks or cancers. It lowered weight only an average of three pounds and diastolic blood pressure only slightly. However, other studies have shown that reducing total...

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Older Exercisers Recover As Fast As Children

As lifelong exercisers age, they find they can’t hit a tennis ball or golf ball as hard, run as fast, lift as heavy, or perform as well, whatever their sport. A study from Yokohama City University in Japan shows that this gradual decline is caused by loss of muscle strength. However, the most significant finding of the study was that older men can recover from hard workouts as quickly as younger men (Applied Physiology, Nutrition and Metabolism, June 2006). Another encouraging study in the same journal, from the University of Southern California in Los Angeles, shows that men over 60 who exercise regularly are far stronger than their non-exercising counterparts.A study from Brock University in Canada also shows that older people can recover...

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Slow Down Gradually After Hard Exercise: Why?

At the end of a marathon, a runner sprints over the finish line, falls down and lies unconscious for a short time. What's the most likely cause? The possibilities include dehydration, hyponatremia (excessive fluid intake with too little salt in the blood), heat stroke, drunkenness, a heart attack or stroke. Usually it is none of these. Almost all athletes who collapse after finishing a marathon suffer from postural hypotension: lack of blood flow to the brain because blood drops from the brain to the legs. Treatment is to lie the person on his back, raise his feet high over his head and wait for him to revive. If he or she is not alert within seconds, you should consider the more serious causes of unconsciousness and get medical help immediately.When...

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Prevent Memory Loss with Exercise

Dementia with aging is associated with every risk factor for heart attacks: smoking, overweight, lack of exercise, high blood pressure and cholesterol, abdominal obesity, diabetes, kidney damage, eating too much saturated fat, refined carbohydrates and calories, not eating enough vegetables, and so forth. A study from the University of Edinburgh in Scotland shows that if you don't want to lose your mental function with aging, you had better start and stay on a vigorous exercise program (Neurology, October 2006).Four hundred and sixty survivors of the Scottish Mental Survey of 1932 were tested on the same general memory tests at age 11 and again at age 79. They also were tested at age 79 for their level of physical fitness by having tests for...

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Fatigue Causes Poor Coordination

Fatigue reduces both strength and accuracy. There's a physiological reason why tiredness weakens muscles. Muscles are made up of thousands of fibers. Each fiber stores sugar. and when it runs out of its stored sugar, it cannot contract effectively. As you tire, your muscles have fewer fibers to contract and you become weaker and less coordinated. This means that a pitcher who is warmed up and fresh will have more active fibers in his muscles and be able to throw more accurately and faster than when he is tired. A fresh football player can kick further and more accurately than when he is tired. That's why professional and college sports teams have large rosters, so they always have plenty of fresh players. The same principle applies to boxers,...

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Calories Burned During Exercise: Measure with METS

To help you determine how many calories you use during various activities, scientists recommend a common measure called a MET, the amount of energy you use when you sleep. It comes out to about one kilo-calorie per kilogram of body weight, or one half a calorie per pound. For example, a 130-pound person burns 60 calories per hour during sleep. A 155-pounder uses 70 calories per hour.When you ride a bicycle at 12 miles per hour, you are exercising at about ten METS or 10 times the amount of energy that you use during sleep. That's the same as running a 10-minute mile, playing racquetball competitively, jumping rope at a moderate pace or playing in a soccer game. To show you how much you increase your metabolism during exercise, consider that...

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Mild Dehydration Causes No Harm

The Gatorade Sports Science Institute in Barrington, Illinois published a study showing that 46 percent of recreational exercisers are dehydrated (Applied Physiology, Nutrition and Metabolism, June 2006). However, with good reason, the study does not say that they are harmed. There is no data anywhere to show that this mild dehydration affects health or athletic performance. Another study from the University of Connecticut shows that a person must lose a tremendous amount of fluid before it affects his performance (Medicine & Science in Sports & Exercise, October 2006).When you exercise for more than an hour, you may need to take fluid, but not too much. Excessive fluid can cause a potentially fatal condition called hyponatremia. Normally,...

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Diabetics Can Exercise Before Or After Meals

Exercise helps to prevent blood sugar from rising too high after meals. The only places that your body can store sugar are in blood, liver and muscles. When a diabetic’s muscles are full of sugar, dietary sugar goes from the intestines into the bloodstream, causing high spikes in blood sugar levels. On the other hand, when the muscles are empty, sugars go from the intestines into the bloodstream and then directly into muscles to prevent the spike. Several studies show that it doesn’t make any difference when you empty your muscle cells. Blood sugar spikes are prevented by exercising both before and after meals. An exciting study from Maastricht University in the Netherlands shows that a single bout of vigorous exercise can help control blood...

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Warm Up to Increase Endurance, Prevent Injuries

Warming up before you exercise helps to prevent injuries and lets you jump higher, run faster, lift heavier or throw further. Your warm-up should involve the same muscles and motions you plan to use in your sport. For example, before you start to run very fast, do a series of runs of gradually-increasing intensity to increase the circulation of blood to the muscles you will be using. Muscles are made up of millions of individual fibers, just like a rope made from many threads. When you start to exercise at a very slow pace, you increase the blood flow to muscle fibers, increase their temperature, and bring in more oxygen, so the muscles are more pliable and resistant to injury. When you contract a muscle for the first time, you use less than...

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Chidren's Exercise: How Much Do They Need?

Children need at least 90 minutes of exercise a day to avoid heart disease when they are older, according to a study reported in Lancet (July 23, 2006). The old guidelines recommending 30 minutes of exercise three times a week, or even an hour a day, do not appear to be adequate for preventing obesity and heart disease. Researchers used heart rate monitors to measure the activity of 1700 nine-to-fifteen-year-olds in Denmark, Estonia, and Portugal. They then calculated a heart-attack risk score consisting of blood pressure, cholesterol, insulin resistance, and skinfold thickness.They compared physical activity from the heart rate monitors with the heart attack risk-factor score and found that the more active the child, the lower the heart attack...

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Eight Glasses of Water a Day Not Needed

Do you believe that a person needs to drink eight glasses of water every day? If you do, you will have a lot of extra trips to the bathroom. Why do so many people believe this rule? The number originally came from the National Academy of Sciences of the United States Food and Nutrition Board, which publishes recommended daily allowances of nutrients. The 1945 edition of the Food and Nutrition Board recommended: "A suitable allowance of water for adults is 2.5 liters (about 8 cups) daily in most instances." This amount is based on the calculation of one milliliter of water for each calorie of food. HOWEVER, the Board also noted that most of the water you need is in the food you eat.All foods contain water. Even the driest nut or seed has a...

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Diabetes Risk: Lifestyle More Important Than Genes

You may inherit a susceptibility to Type II diabetes, but you do not inherit the disease. Risk factors for developing diabetes include: a family history of diabetes; storing fat primarily in the belly; high triglycerides; low HDL (good) cholesterol; blood sugar higher than 200 thirty minutes after a meal; fasting blood sugar above 110; excess hair on the face or body (in women); or diabetes during pregnancy. A person with any of these warning signs should immediately make lifestyle changes to prevent diabetes: avoid refined carbohydrates (foods made with flour, white rice, milled corn; all added sugars and drinks that contain sugar), exercise regularly, lose weight if you are overweight, and keep your weight controlled for the rest of your...

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Lifting Weights Helps to Prevent Diabetes

One third of Americans will become diabetic because they eat too much and exercise too little. A study in Medicine and Science in Sports and Exercise (July 2006) shows that lifting weights can help to prevent and to treat diabetes.Extra fat prevents your body from responding normally to insulin. Before insulin can do its job of driving sugar from the bloodstream into cells, it must first attach to little hooks on cell membranes called insulin receptors. Having extra fat in cells turns these receptors inward, making it far more difficult for insulin to attach to the receptors. This prevents insulin from doing its job of lowering blood sugar levels, even though your body is making plenty of insulin. That’s why anything that makes you fat increases...

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How Much Exercise for Weight Loss?

How much do you need to exercise to lose weight? In one recent study, researchers asked people to walk and count an extra 2000 steps each day (Journal of Human Nutrition & Dietetics, August 2006). This is really a minimal amount of exercise. They also kept complete food diaries. They lost weight and did not increase their food intake. When you start an exercise program, your appetite may increase, but this will not increase your caloric intake to equal the extra calories that you burn. For example, if you burn 600 calories with added exercise, you may take in 200 calories extra and you will lose weight.Exercise helps you lose weight by raising your metabolism so you burn more calories for several hours after you finish exercising. However,...

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Why Blood Pressure Rises with Age

Blood pressure often rises with aging. Contrary to what many doctors think, salt, obesity and alcohol have little to do with this rise. High blood pressure is associated with heart attacks, strokes, aging and death. Recent research shows that high blood pressure associated with aging is probably caused by damage to the arteries leading to the kidneys. Obesity, excess salt and alcohol cause reversible high blood pressure. Taking a large amount of salt can cause your body to retain fluid, enlarge blood volume and raise blood pressure temporarily, but blood pressure returns to normal soon afterwards. For most people, taking in a lot of salt does not raise blood pressure. Drinking alcohol raises blood pressure only for a short time. Obesity is...

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Detecting Performance-Enhancing Drugs

World records in sports are broken by better athletes, better training methods, better nutrition or new drugs. Drugs appear to be the cause of many recent records in sports requiring strength and speed. Many bicycle racers know that some drugs that make them better riders can’t be detected by testing techniques that are available today. A recent study shows that laboratories have no definitive test to discover athletes who take erythropoietin (EPO), a drug to boost their red blood cell counts (Haematologica, August, 2006). Athletes have found that taking very low doses of EPO daily will raise red blood cell counts, and will not give test results high enough to show that they are taking extra EPO.The primary limiting factor to how fast a person...

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Carbohydrates Can Increase Endurance

A study from The University of Bern in Switzerland shows that a high carbohydrate, high-fat diet for three days before competition can help athletes store more fat in their muscles and use much more muscle fat for energy during exercise (European Journal of Applied Physiology, November, 2006). Endurance-trained athletes exercised for three hours to empty sugar and fat reserves from their muscles. Then they ate a high-carbohydrate, low-fat diet for 2.5 days or the same diet with lots of added fat for the last 1.5 days. Athletes who ate the high-carbohydrate, high-fat diet stored 55 percent more fat in their muscles and used more than three times as much of that fat during exercise.The data on fat storage may have no practical value for endurance...

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