The Hygiene Hypothesis

A study on mice may explain why it's not so bad to get lots of infections when you are young. Many studies show that children raised on farms are less likely to develop allergies than those raised in cities. If your immune cells and proteins do not get a lot of practice and learn how to recognize bacteria and viruses, they may attack pollen, mold, dust and other particles that are not bacteria to cause allergies that show up as skin rashes, nasal and lung obstruction and irritation.

Researchers at The University of Marburg in Germany worked with a line of mice that had been genetically programmed to develop asthma. They sprayed Acinetobacter lwoffii, a type of bacteria found in farmyards. into the noses of pregnant mice, and this prevented their newborns from developing asthma (The Journal of Experimental Medicine, December 2009).

Asthma means intermittent obstruction of the bronchial tubes that carry air to and from the lungs. It is caused by the body's immune cells and antibodies attacking something unknown in the lungs to cause the bronchial tubes to fill with mucous, the inner linings of the bronchial tubes to swell, and the muscles surrounding the bronchial tubes to constrict and block the airways.

When a germ gets into your body, your immune cells and antibodies recognize that the germ has surface proteins that are different from your own surface proteins, and they attack it to try to kill it. This causes swelling and irritation. The Hygiene Hypothesis is that exposure to lots of germs when you are young gives your immunity practice in attacking germs so it will not attack your own body tissues or non-germs such as mold, dust or pollen.

This study shows that exposing a pregnant animal to germs can prevent allergies in their offspring. However, it is unreasonable and probably dangerous to recommend exposing pregnant women to infections. We await further studies to see if extreme cleanliness and protection from infections causes allergies.

Stress Fractures Caused by Weak Muscles and Over-Striding

One of the most common injuries in runners is a stress fracture of the lower leg (tibia) because running fast causes the foot to hit the ground with tremendous force that can shatter bones. A study from the University of Minnesota shows that women with stress fractures do not have weaker bones, they have smaller and weaker calf muscles (Medicine & Science in Sports & Exercise, December 2009). Another study from Iowa State University in Ames, in the same journal, shows that longer strides cause the greatest foot strike forces that increase bone fracture risk.

Strong muscles may help to prevent bones from breaking by absorbing more force from the foot hitting the ground during running. Most distance runners do not use weight machines to strengthen their leg muscles. They strengthen their calf muscles by running very fast no more often than three times a week.

In the Iowa study, reducing stride length by ten percent reduced force of the foot striking the ground and therefore reduced force on the tibia.

Shortening your stride will not slow you down. When your foot hits the ground, your Achilles tendon contracts to store up to 60 percent of your foot strike force. Then when you step off that foot, your Achilles tendon releases the stored energy to drive you forward. Over-striding deprives you of some of this stored energy. Since many runners take strides that are too long, shortening stride length usually allows them to increase cadence and will help to increase speed and endurance.

Why Sprinting Improves Endurance

Jens Bangsbo of the University of Copenhagen has shown that if you want to run, cycle or swim faster at any distance, you have to train at a pace that is almost as fast as you can move (Journal of Applied Physiology, November 2009). He asked competitive distance runners to reduce their mileage by 25 percent, and to run 8 to 12 30-second sprints 2-3 times a week, with some additional 0.6-0.8 mile sprints 1 or 2 times per week, for 6 to 9 weeks. The control group of runners continued their regular training program, and showed no improvement. The sprint group improved both their 3K (1.8 mile) and 10K (6 mile) race times by more than three percent (more than a minute in the 10-K race). Half of them ran their best times ever, even though many had been racing for more than five years.

Two years ago, Dr. Bangsbo did ground-breaking research supporting the leading theory that exhaustion of the sodium- potassium pump is the major cause of muscle fatigue during exercise (Acta Physiologica, November 2007). In this new study, he shows how sprint training improves a muscle's capacity to pump potassium back inside muscle cells during exercise, which helps all athletes run or cycle faster in competition, even in endurance events such as marathons and multi-day bicycle races.

A muscle can contract only if it has an electrical charge across the muscle cell membrane. This electrical charge comes mainly from having sodium primarily outside the cell and potassium primarily inside the cell. This higher concentration of sodium outside the cell and higher concentration of potassium inside the cell is maintained by sodium-potassium pumps in the cell membranes. The pumps get their energy from an enzyme called ATPase.

When the brain sends electrical signals along nerves leading to each muscle fiber, sodium moves rapidly into muscle cells followed by an equivalent movement of potassium out of the cells, causing the muscle fibers to contract. However, the sodium- potassium pump cannot pump potassium back into the cells as fast as the rapidly-contracting muscle cells move potassium out.

Dr. Bangsbo showed that during rapid contractions, muscle cells lose potassium so fast that there is a doubling of the potassium outside cells in less than a minute. The electrical charge between the inside and outside of muscle cells is reduced, and they contract with much less force until finally they cannot contract at all. During continuous contractions of muscles, the loss of force from a muscle contraction is directly proportional to the amount of potassium that goes outside the cells.

Over time, repeated muscle contractions themselves will markedly increase the ability of the sodium-potassium pump to pump potassium into cells. The greater the force on a muscle during training, the more effectively the potassium pump can pump potassium back into muscles, resulting in greater endurance for the athlete. So intense training is necessary for endurance, and any training strategy that increases the number of intense workouts will give the athlete greater endurance.

You can also increase the effectiveness of the sodium potassium pumps by being excited before a race (which increases adrenalin), and by eating before and during races (which raises insulin levels). Hormones known to strengthen the sodium- potassium pump, and therefore to increase endurance, include adrenalin, insulin, insulin-like growth factor I, calcitonins, amylin, thyroid, testosterone and cortisones.

How to apply this information to your training program:

You cannot gain maximum endurance just with continuous exercise. To improve your potassium-sodium pumps, you have to put maximum force on your muscles. This requires some form of interval training. (CAUTION: Intense exercise can kill a person with blocked arteries to the heart; check with your doctor before increasing the intensity of your program.)

Intervals are classified as short intervals that take fewer than 30 seconds and do not generate significant amounts of lactic acid; and long intervals that take more than two minutes and generate large amounts of lactic acid. The longest you can exercise with maximal force on muscles is about 30 seconds. All competitive athletes should do some sort of 30-second interval. Nobody knows how often you have to do this, but most runners and cyclists do short intervals once or twice a seek. You probably should do long intervals also. However, applying near-maximal force on muscles for more than 30 seconds causes considerable muscle damage, so you have to allow muscles to recover by doing slow training for one or two days afterwards.

Since short intervals do not accumulate much lactic acid, you can do a large number of repetitions during a single workout. Long intervals cause a tremendous amount of muscle damage, so you can only do a few long intervals during a workout. A sound endurance program should include a lot of slow miles, one or two workouts with many short intervals, and probably at least one workout that includes a few long intervals each week.
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Junk Food Alters Intestinal Bacteria in Just One Day

After just one day of switching from a plant-based diet to a high-fat-and-sugar diet, mice with human intestinal bacteria developed bacteria associated with obesity in humans, and soon became grossly obese (Science Translational Medicine, November 11, 2009).

Dr. Jeffrey Gordon of Washington University in St Louis first showed that certain types of bacteria in the human intestinal tract can break down food more efficiently and help you absorb a greater percentage of calories from the food that you eat. He also showed that humans whose intestinal tracts are dominated by these bacteria tend to be overweight.

In this new study, Dr. Gordon created germ-free mice and fed them a low-fat, plant-rich diet. Then he fed them bacteria extracted from human stool and continued to feed them a low-fat, plant-based diet for one month. By sequencing the microbes' 16S rRNA gene, he showed that the intestinal bacteria in the mice were the same as those living in a healthy human's intestines.

One month later, he switched half the mice to a high-fat, high-sugar diet. After 24 hours, the intestines of the mice had increases in the obesity-causing bacteria, Firmicutes, and decreases in the obesity-preventing Bacteroidetes. The mice continued to grow fatter and fatter, even when switched back to the low-fat, plant-based diet.

What does this mean to you? When you eat a diet rich in refined carbohydrates (fruit juices, sugared drinks and foods made from flour and sugar) and fat (meat, fried foods, and fatty desserts), you develop intestines full of bacteria that thrive on these foods, break down these foods more efficiently, and then absorb far more calories from these foods. If you want your gut flora to help you maintain a healthful weight, you should eat primarily fruits, vegetables, whole grains, beans, seeds and nuts.

New Vitamin D Recommendations

At the University of Toronto School of Medicine's "Diagnosis and Treatment of Vitamin D Deficiency" conference on November 3, 2009, thirty of the world's leading researchers on vitamin D recommended 2,000 IU of vitamin D daily (the current recommendation is 600 IU). Vitamin D3 blood levels should be 100-150 nmol/L (40-60 ng/ml); the existing recommendation is 30-50 nmol/L.

Vitamin D pioneer Dr. Cedric Garland presented data showing that raising vitamin D levels to 200 nmol/L decreased breast cancer risk more than 77 percent. He said: "Breast cancer is a disease so directly related to vitamin D deficiency that a woman's risk of contracting the disease can be virtually eradicated by elevating her vitamin D status to near that level." Recent work has shown that all cells in the body have "vitamin D receptors" to control normal cell growth. Garland presented new evidence that low vitamin D status compromises the integrity of calcium-based cellular bonding within tissues, which allows rogue cancer cells to spread more readily.

Vitamin D deficiency is associated with at least 24 cancers, diabetes, multiple sclerosis, heart disease, falls and fractures, psoriasis and many other health problems.
More on Vitamin D

Will avoiding dietary sugar prolong life?

Nobody has yet shown any way to extend the life span of humans. However, both exercise and calorie restriction (with adequate nutrients) have been shown to extend the life span of animals. Both of these measures apparently extend life by increasing the number and size of mitochondria in cells and making them turn food into energy more efficiently. Each cell in your body contains up to several hundred mitochondria which provide the most efficient chemical reactions in your body for converting food into energy.

An exciting new study on worms offers a potential method for you to prolong life and good health. When blood sugar levels rise too high, sugar enters cells in large amounts. An earlier study showed that adding sugar to the diet of the worm, C. Elegans, shortens its life (Cell Metabolism, October 2007). Now the researchers have found that preventing sugar from entering cells by altering the genes for DAF-2, DAF-16 and Heat Shock Factor-1 causes the same changes as avoiding sugar and extends the worms' life span up to 20 percent (Cell Metabolism, November 2009). These benefits could also occur in humans because we have the same three genes that control sugar entry into cells as those of the worms.

Calorie restriction and exercise probably prolong life by the same mechanism: they enlarge and activate mitochondria in cells that turn food to energy. This helps mitochondria to clear free radicals much more rapidly from the body. Free radicals can damage cells and therefore shorten life. The worms' cells responded to the absence of sugar inside cells by increasing their ability to clear free radicals from their bodies which prolonged their lives. Indeed, when sugar was allowed to again enter their cells, they still could clear free radicals faster and live longer because their enlarged mitochondria were more efficient in removing free radicals.

This research on worms questions the way doctors treat type II diabetes when they prescribe drugs to lower blood sugar levels by driving sugar into cells. The best treatment may be to develop diets and drugs that prevent blood sugar from entering cells in the first place.

For now, we know that you will shorten your life and increase risk for many diseases by allowing blood sugar levels to rise too high after meals. A diet that keeps sugar from rising too high after meals (and reduces the entry of sugar into cells) can prevent diabetes, help control all the side effects of diabetes (JAMA, December 16, 2008), cause the most weight loss, and allow many type II diabetics to safely stop their medications (Nutrition and Metabolism, January 2009). Avoid foods that cause the highest rise in blood sugar levels: sugar in liquid form (sugared drinks, fruit juices, and adding sugar to any drink); foods made from flour (bread, spaghetti, macaroni, pretzels, bagels and so forth); and foods with added sugar.

You should also exercise every day. Exercise causes muscles to remove sugar from the bloodstream at a very rapid rate and this effect lasts maximally for about half hour after you stop exercising, then tapers off until it stops completely after about 17 hours. Furthermore, since lack of vitamin D causes high blood sugar levels, you should make sure that your blood level of vitamin D3 is above 75 nmol/L. New vitamin D recommendations

Just Getting Old Does Not Cause Diabetes

A study from the University of Pittsburgh shows that the marked increase in diabetes in older people is caused by obesity and lack of exercise, not by aging alone (Diabetes Care, August 2009). Most cases of diabetes are caused by cells not being able to respond to insulin, rather than by lack of insulin. Inability to respond adequately to insulin is caused by being overweight, not exercising, lacking vitamin D and/or eating too many refined carbohydrates.

In this study, the same insulin responses were found in young and old endurance-trained athletes, young and old normal-weight subjects, and young and old obese subjects. Regardless of age, athletes had better insulin responses than normal-weight sedentary subjects, who had better insulin responses than overweight people.

If you are overweight, try to lose the extra weight. Check with your doctor and start or continue an exercise program. Get a blood test called vitamin D3. If it is below 75 nmol/L, you need more sunlight or vitamin D pills. When you are not exercising, avoid sugar water and flour.
More on diabetes prevention and treatment

No Evidence Cycling Weakens Bones

No data exists in the scientific literature showing that any type of exercise weakens bones. Bone growth depends on the forces exerted on them by gravity and contracting muscles. So any activity or exercise that causes you to contract your muscles will strengthen bones (Medicine & Science in Sports & Exercise, November 2009).

Previous studies showed that world class cyclists had reduced bone densities in their spines. However, bone density tests do not measure bones strength. They measure how much bones block X-rays that try to pass through them. The only way to measure bone strength is to see how much force it takes to break a bone.

The most likely explanations for broken bones in cyclists are high-impact crashes and/or lack of vitamin D. I recommend that all cyclists get a blood test called Vitamin D3 in December or January. If it is below 75 nmol/L, they are deficient in vitamin D and at increased risk for breaking bones. To prevent fractures, they should do winter training in the southern sunbelt or take at least 800 IU of Vitamin D3 per day.

A recent review of 12 blinded, controlled scientific studies showed that oral vitamin D reduced non-vertebral and hip fractures in patients over 65 years of age (Evidence-Based Medicine, October 2009). Blood levels of vitamin D below 75 nmol/L cause parathyroid hormone levels to rise too high, which causes osteoporosis. A main function of vitamin D is to increase calcium absorption from the intestines into the bloodstream. When blood levels of vitamin D fall below 75 nmol/L, levels of ionizable calcium drop. This causes the parathyroid gland to produce large amounts of its hormone. Higher than normal blood parathyroid hormone levels take calcium out of bones to cause osteoporosis.

Fasting Does Not Increase Endurance

Some people think (incorrectly) that fasting before a race or competition will increase their endurance. Fasting weakens and tires you. How long you can exercise a muscle depends on how much sugar, called glycogen, you can store in that muscle and how long you can keep it there. When a muscle runs out of its stored glycogen, it slows down because it requires more oxygen to burn more fat. It also accumulates more lactic acid to become acidic which causes a burning pain, and it becomes more difficult to coordinate.

Every time you move a muscle, some of the stored glycogen is used up. Every time you eat, some of the food can be stored as glycogen in that muscle. When you go for more than an hour without eating, you use up glycogen without replacing it. If you don't eat before you compete, you start with reduced stores of glycogen in your muscles and you will not be able to compete at your best.

It is nonsensical to claim that fasting increases endurance by causing muscles to burn more fat and less glycogen so muscles can retain their stored glycogen longer. When you start with less glycogen, you still use it up faster and run out of fuel earlier. You can increase endurance by cutting back on exercise four days before your competition and eating as much or more than usual. Eat one to three hours before competing. If your event lasts more than an hour, take fluid, sugar and protein (whole grain bars, sugared drinks, etc.) during your event.

Chronic Fatigue Syndrome - a new explanation

Sixty-seven percent of 101 patients diagnosed with Chronic Fatigue Syndrome (CFS) were found to be infected with a retrovirus called XMRV (Science, published online October 8, 2009). One hundred percent of those with CFS who subsequently developed lymphomas or leukemias were infected with the XMRV virus. If further studies confirm this finding, doctors will soon have a test to diagnose this horrible condition and possibly a vaccine to prevent it.

More than a million Americans are seriously ill with Chronic Fatigue Syndrome, also known as Myalgic encephalomyelitis. CFS symptoms include severe weakness, exhaustion after any activity, loss of memory, and chronic recurrent infections. Patients rarely recover.

The retrovirus XMRV was first found in humans in 2006, in prostate cancer cells. It has been shown to cause nerve damage, immune deficiency, lymphoma and leukemia in animals. Retroviruses do not have their own DNA; they use the DNA of the host cells they invade. Retroviruses include HIV that causes AIDS, and Human Lymphotropic Viruses that cause leukemia and lymphoma. Just as some people infected with HIV do not develop AIDS, not everyone infected with XMRV will develop CFS. XMRV has been found in 3.7 percent of healthy Americans tested, adding up to an estimated 10 million Americans carrying this virus.

Although not proven yet, there is every reason to believe that XMRV is spread by exposure to body fluids (saliva, blood, semen). Having an infection with one of these retroviruses impairs your immunity so that you are more likely to become infected when exposured to any other germ.

The Potassium Deficiency Myth

Sports drink promoters have convinced many athletes that they need special drinks to replace potassium during exercise. A recent study of female soccer players confirms that this is a myth (International Journal of Sports Medicine, June 2009). When body levels of potassium are low, the kidneys and sweat glands conserve potassium so effectively that potassium deficiency rarely occurs.

Tiredness in healthy athletes can have many causes, but low potassium is not one of them. Many years ago, Dave Costill of Ball State University tried to create potassium deficiency in healthy national champion runners. He couldn't do it because potassium is found in all foods except refined sugar, and his athletes would not stay on a diet that consisted only of hard candy. Even with prolonged exercise in very hot weather, potassium needs can be met by eating virtually any food.

Potassium deficiency CAN be caused by certain drugs, such as diuretics or corticosteroids, or by severe diarrhea or repeated vomiting. One of the best female long-distance runners in the country came to me to find a cause for her sudden drop in performance. All tests I ordered were normal except for a low blood level of potassium. I knew that hard exercise does not cause potassium deficiency and that the most common cause of potassium deficiency is vomiting, but she repeatedly denied doing this. I then requested that she collect her urine for one day and the laboratory reported that it contained three times as much potassium as normal. This proved that she was bulemic. To control her weight, she was sticking her finger down her throat to makie herself throw up. After she was able to accept the diagnosis, she got help, stopped vomiting and went on to win several national long distance running titles.

With vomiting, you throw up the stomach's acid (hydrogen) and the blood becomes alkaline. This causes the kidneys to retain hydrogen and consequently lose huge amounts of potassium in the urine. In both athletes and non-athletes, the most common cause of low potassium blood levels and high potassium urine levels is vomiting.

Metabolic Syndrome and Diabetes

As the standard of living in a country increases, so does the incidence of Metabolic Syndrome. Today, one of three North Americans will suffer premature death from the consequences of Metabolic Syndrome, which is caused too little activity and too much food (The Journal of Clinical Hypertension, September 2009). Warning signs include: abdominal obesity, high triglycerides, low good HDL cholesterol, overweight, high blood sugar and high HBA1C. (HBA1C is a blood test that measures sugar stuck on cells. An HBA1C greater than 5.7 shows that you have Metabolic Syndrome).

Metabolic Syndrome means that you are in the early stages of diabetes. If you store fat primarily in your belly, you probably have high blood insulin levels, a sign that your body cannot respond adequately to insulin. High insulin levels are caused by high blood sugar levels that cause blood sugar to stick to the surface of cell membranes. Once there, sugar can never get off. It is eventually converted to sorbitol which destroys the cell to cause all the side effects of diabetes. As long as your pancreas still makes insulin, you can reverse metabolic syndrome and diabetes. However, once your pancreas dies you cannot make insulin and your diabetes is not curable.

Read my recommendations on preventing diatetes, and for treating it if you have already been diagnosed. In summary:

• Exercise
• Don't be overweight
• Avoid refined carbohydrates except during exercise
• Make sure you have enough vitamin D
• Don't smoke
• Limit alcohol to no more than two drinks per day
• Eat a healthful diet with plenty of vegetables, beans, whole grains, nuts and other seeds.

Preventing Muscle Cramps

Most older textbooks explain that muscle cramps are caused by lack of water (dehydration) and lack of salt. However, studies on endurance athletes show that athletes who cramp do not have less body water or sodium than those who do not cramp (British Journal of Sports Medicine, June 2009). So the current explanation for muscle cramps in conditioned athletes is that prolonged, intense exercise damages muscles, which can cause sustained contractions or cramps.

Cramps may occur as a side effect of drugs used to treat high cholesterol, high blood pressure or diabetes. Oral contraceptives, various other drugs or alcohol can also cause muscle cramps. If you suffer from recurrent muscle cramps that cannot be explained, check with your doctor. Possible causes include pinched nerves, Parkinson's disease, hypothyroidism, diabetes, narrowed arteries, low blood mineral levels, or metabolic diseases that cause muscle damage. However, these diseases are rarely the cause of cramps in athletes.

Cramps can often be prevented by slowing down when a muscle starts to feel tight. However, athletes usually are not willing to do this during competition or hard training, so they will continue to suffer from occasional cramps and work them out as they occur. You can help to prevent cramps with a training program that includes both hard days and recovery days. We do this by cycling at 18-20 mph pace on Tuesdays, Thursdays and Saturdays and 10-12 mph pace on the other four days.

New Rules for Sunscreens

If you use sunscreens, be sure to reapply them frequently. Many sunscreens contain the filters octylmethoxycinnamate, benzophenone-3 or octocrylene, which reflect ultra violet rays away from your skin to protect it only when they are on the surface of the skin. However, when these sunscreens are absorbed and the skin is not re-coated, they increase skin production of harmful oxidants that can cause skin aging and cancer (Free Radical Biology & Medicine, September 2009). Reapplying the sun screen so some remains on the skin's surface can prevent this damage.

• Before you go out in the sun, apply sunscreens to the areas with the most exposure to sunlight over your lifetime: the top of your ears, your face, the back of your neck, and your arms and hands. It is the cumulative exposure to UV light that increases skin cancer and aging.

• To meet your daily vitamin D requirements from sunlight, expose your legs or other areas of your body that have received little cumulative sun exposure over your lifetime. Take care to avoid sunburn.

• Reapply sunscreens every hour or two, particularly when you are swimming or sweating.

• Some sunscreens contain stronger UVA filters (avobenzone, mexoryl, titanium dioxide or zinc) that are less likely to be absorbed into the skin. You do not need to reapply these if they leave a visible white paste on your skin. Check the list of ingredients.

A comprehensive review of more than 1000 sunscreens was conducted by the Environmental Working Group in summer of 2009. Their findings, with brand name listings and recommendations, are available at

Large Thighs are Good

Large thighs appear to confer health benefits, not risks. A study reported this month shows that people who have small thigh muscles, independent of how much fat they have in their bellies, are at increased risk for premature death, particularly from heart attacks (British Medical Journal, September 2009). 2800 men and women aged 35 to 65 had their thighs measured and were followed for ten years. Those whose thigh circumference was below 24 inches (60 cm) were at increased risk for death from heart attacks.

Other studies show that having very low body fat is also associated with early death, as are being overfat or storing fat primarily in the belly. If you store most of your fat in your belly and have very small thighs or buttocks, you are probably already diabetic or prediabetic and at significant risk for a heart attack.
Another interesting study on benefits of thigh fat
Why belly fat is risky

CRP Better Predictor of Heart Attacks than Cholesterol

Blood tests for cholesterol and C-reactive protein (CRP) both help to measure heart attack risk, but CRP may be more important. CRP measures inflammation which indicates an overactive immunity, while cholesterol measures a type of fat in your blood. Having a high CRP blood test increases your risk of suffering a heart attack or stroke by twice as much as having a high cholesterol (New England Journal of Medicine, November 2002). Everything that activates your immunity can increase risk for heart attacks and everything that damages your body turns on your immunity. Inflammation is part of the immune reaction that protects you from infection. It causes redness, pain and swelling, and can damage the inner lining of arteries or break off clots from arteries to block the flow of blood which can cause strokes and heart attacks.

If you have a high CRP, try to correct the known causes: any type of infection such as chronic gum disease, high blood pressure, alcohol use, smoking, low levels of physical activity, chronic fatigue, eating a high protein/high meat diet, or having elevated triglycerides, insulin resistance or diabetes. People with sleep disturbances, depression, or any of the "auto-immune" diseases such as rheumatiod arthritis or psoriasis are also likely to have a high CRP and are at increased risk for heart attacks. More

Osteoarthritis: Treat with Exercise

A review article from the University of British Columbia in Vancouver shows that exercise does not increase the rate of knee damage in people with osteoarthritis, and usually reduces knee pain and disability (Canadian Family Physician, September 2009).

If you develop pain in your knee that was not caused by an accident or trauma, your doctor will usually check you for known causes of joint damage. If he finds no cause, he will tell you that you have osteoarthritis, which means that he doesn't know why your knee hurts. Most people with osteoarthritis (not associated with trauma) are overweight, do not exercise, and/or have weak muscles that support knee movements.

Osteoarthritis causes a higher incidence of disability than any other chronic condition. It makes exercise difficult, and not exercising increases risk for heart attacks. One in three North Americans over 60 have X ray evidence of osteoarthritis.

People with osteoarthritis should avoid contact sports, but exercise is more effective than any medication to treat this condition. The best activities include swimming and other water- based exercises, stationary cycling or cycling on the road, and muscle strengthening exercises using Nautilus machines or similar equipment at a gym. People with knee osteoarthritis should avoid sports that involve sudden shocks to the knee, such as when the foot hits the ground during running. Inactivity and overweight increase your chances of further knee damage and often lead to a joint replacement. More on arthritis

Preventing Loss of Muscle Strength with Aging

As you age, you lose muscle size and strength much faster than you lose endurance or coordination. Researchers at the University of Nottingham in England show that a major cause of loss of muscle is that aging prevents muscles from responding to insulin and that exercising helps to slow this loss of muscle size and strength (The American Journal of Clinical Nutrition, September 2009).

Insulin drives amino acids into muscles to help them recover from exercise and maintain their size. Researchers traced radioactive amino acids and showed that insulin drives the amino acids into muscles much more effectively in 25-year-olds than in 60-year-olds. They also showed that the blood flow in younger people's legs is much greater and supplies far more nutrients and hormones. However, three exercise sessions per week over 20 weeks markedly increased blood flow in the legs of the older subjects, enough to reverse muscle wasting.

People of all ages can use this information to help themselves become stronger. Athletes in all sports train by stressing and recovering. They take a hard workout, damage their muscles, feel sore the next morning, and then take easy workouts until the muscles heal and the soreness goes away. The athlete who can recover the fastest can do the most intense workouts and gain the most strength.

Eating a high carbohydrate-high protein meal within half an hour after finishing a workout raises insulin levels, increases amino acid absorption into muscle and hastens recovery (Journal of Applied Physiology, May 2009). The carbohydrates cause a high rise in blood sugar that causes the pancreas to release insulin. Insulin drives the protein building blocks (amino acids) in the meal into muscle cells to hasten healing from intense workouts. Muscles are extraordinarily sensitive to insulin during exercise and for up to a half hour after finishing exercise, so the fastest way to recover is to eat protein- and carbohydrate-rich foods during the last part of your workout or within half an hour after you finish.

Here's how Diana and I (ages 67 and 74) use this information on insulin sensitivity. We ride hard and fast for about 20 miles on Tuesdays, Thursdays and Saturdays. On our recovery days, we ride slowly for one to three hours. Mid-day we go to a buffet restaurant and eat a large meal with fish, shrimp, vegetables and other sources of protein and carbohydrates. After eating, we ride slowly for one or two more hours. Riding before we eat makes our muscles very sensitive to insulin. This causes insulin to drive amino acids rapidly into our muscles and help them recover faster. Riding after we eat helps us to avoid a high rise in blood sugar that damages cells. You can use either plant or animal sources of protein; both contain all of the essential amino acids necessary for cell growth.
More on principles of training

What Causes Prostate Cancer?

We don't know what causes prostate cancer, but a study from Harvard School of Public Health shows an association between the common sexually transmitted infection, Trichomonas vaginalis, and risk of the type of prostate cancer that kills (Journal of the National Cancer Institute, September 9, 2009). Researchers analyzed blood samples collected in 1982 from 673 men who were diagnosed with prostate cancer more than ten years later. Trichomonas vaginalis infection was associated with a more than triple risk for the type of prostate cancer that kills.

Trichomonas vaginalis infects about 174 million people each year and is the most common non-viral sexually transmitted infection. Up to three-quarters of men infected with Trichomonas vaginalis may have no symptoms at all. Trichomanes can usually be cured just by having all sexual contacts take metronidazole for five to ten days.

Several other cancers are caused by bacterial infections. For example, the bacterium Helicobacter pylori is the most common cause of stomach cancer. Bacteroides fragilis, a bacterium that causes diarrhea, has been associated with colon cancer (Nature Medicine, September, 2009). Chronic infections activate your immune system to cause inflammation, which can block apoptosis to cause cancer.

More than 90 percent of prostate cancers probably should not be treated because they cause no harm. A study in the Journal of the American Medical Association (September 15, 2009) followed men with early stage prostate cancer who were cared for without surgery or radiation. Ten years later, only six percent had died from prostate cancer. The average time from diagnosis to death for untreated prostate cancer is more than 22 years. However, five percent of prostate cancers may need immediate treatment as they grow rapidly and can kill. A reliable test that tells which prostate cancers are likely to kill would save anxiety, potency and continence for a lot of men. Such a test is not available at this time. The authors of this study recommend that doctors and patients reconsider the watch and wait option. More on prostate cancer

Use Lactate Threshold instead of Maximum Heart Rate

My report on the unreliable Maximum Heart Rate formula brought many questions on how heart rate SHOULD be used for training. Competitive athletes often use a guide called lactate threshold (LT). When you exercise, your muscles require oxygen to convert food to energy. If you exercise so intensely that you cannot get enough oxygen, lactic acid accumulates in your muscles and spills over into your bloodstream. This makes your muscles more acidic which causes terrible burning, and you to become short of breath and slow down as you struggle to get more oxygen. Your lactate threshold occurs when you exercise at the highest average heart rate you can maintain for 45-60 minutes. offers the following guidelines for cyclists; the same principles can be used in any other endurance sport.

"A good way to find your LT is to ride a fairly flat 15-mile course at a hard pace. Use a heart monitor that averages heart rate for the distance or just check it occasionally to see where HR settles.

You'll quickly find that you can maintain a certain high HR, but if you go a few beats higher you'll start panting and be unable to control your breathing. Trial and error will reveal the highest HR you can maintain for the distance. That's your LT.

Three simple exercise zones based on your LT heart rate are sufficient. These guidelines should work for most riders:
Recovery takes place about 40 beats below LT
Endurance is built on rides about 25 beats below LT
Breakthrough training is done from 10 beats below LT to about 5 beats above LT
No heart monitor? You can do just as well by monitoring your perceived exertion. For instance, recovery rides should be so easy that you barely feel the pedals. The idea is to take a 'walk' on the bike. Hard efforts, such as intervals and climbing, should be at the limit separating steady-but-labored breathing from panting and gasping. By experimenting you'll find this LT boundary."

Whatever your sport, I recommend subscribing to RBR's free newsletter; it's full of useful information for exercisers.

NSAIDs Interfere with Proper Training

Ibuprofen and other NSAIDs (Non Steroidal Anti-Inflammatory Drugs - Motrin, Advil, Alleve and so forth), taken before or after exercise, interfere with the benefits of training for fitness and athletic competition because they delay healing of damaged muscles (British Journal of Sports Medicine, August 2009). You train for sports by taking a hard workout that damages muscles and makes them feel sore. You then take easy, less intense workouts for as long as it takes for the soreness to go away. Only then should you take intense workouts again. Swimmers take hard and easy workouts every day, but athletes in virtually all other sports allow at least 48 hours between intense workouts.

Biopsies done the day after a hard workout show bleeding into the muscle fibers and disruption of the Z-bands that hold muscle fibers together. Injured muscles release healing prostaglandins that cause collagen to be laid down in muscle fibers to make them larger and stronger. They also cause pain. NSAIDs block the training effect by blocking healing prostaglandins, thus delaying recovery and collagen production. They prevent bones, muscles, tendon and ligaments from thickening and becoming stronger.

Athletes taking NSAIDs during competition are at increased risk for bleeding into their kidneys, and for intestinal bacteria to enter their bloodstreams (Brain, Behavior and Immunity, November 2006). An estimated 60 percent of athletes competing in triathlons and other endurance events take NSAIDs because they think that it will block the pain of competition. NSAIDs have not been shown to block the pain and fatigue of competing in athletic events that require endurance.

Ordinary aspirin delays muscle healing by blocking many of the same healing prostaglandins that are blocked by NSAIDs. Aspirin also increases risk for
bleeding if you should have an accident.

Your Appendix is Not Useless

You may have had your appendix removed because doctors believed that it was a useless vestigial organ. Now researchers have found that it serves as a storage tank for healthful germs that live in your intestines. These good bacteria help to break down food so you can absorb its nutrients. They also prime your immune system to recognize harmful germs and prevent them from invading your body, prevent your immune system from attacking your own body to cause auto-immune disease, and produce immune factors that may prevent colon cancer (Microbiology, February 9, 2009).

When you have diarrhea, bad bacteria can remove the good bacteria in the intestines and colon. A study from Duke University shows that the bad bacteria cannot dislodge the good bacteria from the appendix because its inner lining is covered with a thicker and far more potent biofilm (a layer of bacteria, mucous and immune system cells) than is found in the intestines (Journal of Evolutionary Biology, August 2009). No matter how severe the diarrhea or how extensively the bad bacteria drive out the good bacteria from the intestines, the good bacteria persist in the appendix and eventually re-colonize the rest of the intestines. More on good bacteria

Tennis Elbow: New Treatment

Physical therapists at the Nicholas Institute of Sports Medicine and Athletic Trauma in New York City report that eccentric exercises offer a simple and effective cure for tennis elbow (July 2009 annual meeting of the American Orthopedic Society for Sports Medicine). The researchers prescribed standard physical therapy for tennis elbow to 10 patients, and physical therapy plus special eccentric exercises to 11 others. In less than two months the eccentric group reported an 81 percent improvement in pain and a 72 percent improvement in strength, while the control group had not improved.

(Eccentric contractions occur during a biceps curl when you lower the weight and your biceps lengthens. Concentric contractions occur when you raise the weight and your biceps muscle shortens.)

You don't have to play tennis to develop tennis elbow. It can be due to any movement that puts excessive force on the wrist muscles. Tennis elbow refers to elbow pain as the result of an injury to the elbow tendons that bend and straighten the wrist. Hold your hand down with your thumb on the outside (lateral to your hand) and your elbow straight. Pain on the lateral (outside) part of your elbow is called backhand tennis elbow. Pain on the medial (inside) part is called forehand tennis elbow.

The exercise is done with an inexpensive piece of equipment called the Thera-Band Flexbar, available at Hold the bar upright with your hand of the affected side. With your hand of the healthy side, grasp the bar near the top and twist it in front of the body. Then use the sore elbow-side hand to slowly untwist the bar by flexing the wrist. Video of the exercise

Burning on Urination May be STD Infection

One in three single, sexually-active Americans who have more than one partner carry a sexually transmitted disease that may not respond to treatment. These people may have no symptoms at all, or they may have pain during sexual relations, burning on urination, discomfort when the bladder is full, frequency, urgency and night-time urination, vaginal discomfort, difficulty starting the urinary stream, or discomfort in the pelvis. These people go from doctor to doctor, get lots of tests which fail to yield a diagnosis, and continue in their misery and spreading of disease.

This month, researchers in Greece showed that many of these people suffer from infections with intracellular bacteria: mycoplasma, chlamydia or ureaplasma (Urology, July 2009). Most cultures done in medical laboratories fail to pick up these infections. 153 patients had some of the above symptoms and had either failed a course of antibiotics or had negative routine cultures. The patients had cultures taken from their urine, urinary tube, vagina, and cervix. Fifty-three percent of these "incurable" patients were infected with ureaplasma urealyticum. Eighty-two percent of patients positive for ureaplasma urealyticum had other pathogens. A single dose of one gram of azithromycin was given to all culture-positive patients and their sexual partners. Those with a positive culture one month after therapy (4.9 percent) were successfully treated with seven days of doxycycline 100mg twice daily. All of the patients improved, but many continued to suffer pain in the pelvis.

Faster Runners Have Longer Strides

When most experienced runners go 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.

However, you cannot run faster by consciously trying to increase your stride length. When you try to take longer strides than what feels natural to you, you lose energy and run more slowly.

Your heel hits the ground with great force. The tendons in your legs absorb some of this energy and then contract forcibly after the heel strikes 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.

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.

New Explanation for DASH Diet Success

If your systolic (heart contraction) blood pressure is above 120 mm/hg before you go to bed at night, you have high blood pressure and are at increased risk for heart attacks, strokes and premature death. You can protect yourself from premature death caused by high blood pressure with the DASH diet, exercising, avoiding overweight, and getting adequate amounts of vitamin D.

The DASH diet is based on fruits, vegetables, whole grains, fish, poultry, nuts and legumes, and low-fat dairy. Several studies have shown that the DASH diet lowers high blood pressure as effectively as most blood pressure drugs, prolongs life, and prevents heart attacks and strokes. The most common explanation for this success has been the high potassium, magnesium and fiber content of vegetables. However, a study from Medical University of South Carolina in Charleston (Journal of Human Hypertension, August 2009) shows that the DASH diet lowers blood pressure better than a diet supplemented with extra potassium, magnesium and fiber, so there must be other factors.

Now a study of 4706 men and women aged 40-59 in the United States, the United Kingdom, China, and Japan suggests that glutamic acid, an amino acid that relaxes blood vessels, may explain why a high-vegetable diet treats high blood pressure. (Circulation, August 2009.) A vegetable-based diet has five percent more glutamic acid than a diet rich in meat and prepared foods.

Calories do count; the DASH diet may not lower high blood pressure if you eat too much food. More on the DASH diet

Getting Rid of Belly Fat

Sit-ups will not get rid of belly fat because you cannot get rid of fat in a certain area just by exercising the muscles underneath that fat. You will lose the most belly fat by exercising intensely in any sport (Medicine and Science in Sports and Exercise, November 2008). Three groups of overweight, middle-aged women who suffered from Metabolic Syndrome completed 16-week programs of: (1) continuing their existing levels of activity with no change; (2) low-intensity exercise training five times a week at a level that did not cause breathing hard; and (3) high-intensity exercise training with three days a week hard enough to become short of breath and two days a week at an intensity not becoming short of breath. Cat scan X rays and air displacement plethysmography studies showed that the high intensity exercisers lost belly fat, both underneath their skin and inside their bellies. The low-intensity exercisers lost no measurable belly fat.

Storing extra fat in the belly causes people to become diabetic. Full fat cells produce hormones that prevent the body from responding to insulin so that blood sugar rises too high, causing sugar to stick to cells and damaging cells anywhere in the body. Those who store fat primarily in the belly are the ones most likely to suffer high rises in blood sugar. If you store fat primarily in your belly, have high blood levels of triglycerides and sugar, and low levels of the good HDL cholesterol, you meet the definition of Metabolic Syndrome and the odds are that you are diabetic, or will become diabetic soon. You are likely to suffer a premature death unless you make major lifestyle changes: lose weight, exercise, avoid refined carbohydrates (except during exercise), and make sure you get enough vitamin D.

Exercise can cause heart attacks in people with blocked arteries, and intense exercise increases the risk. Almost 80 percent of diabetics die of heart attacks. Check with your doctor before starting a new exercise program or increasing the intensity of your existing program.

Caffeine May Help to Prevent Alzheimer's

Two studies in the July 2009 issue of Journal of Alzheimer's Disease show that the equivalent of five cups of coffee a day reverses memory loss in mice with Alzheimer's disease. The coffee also reduced blood and brain levels of beta-amyloid,the abnormal protein that may cause Alzheimer's disease in mice and people. Other studies by the same researchers at the University of Florida show that caffeine lowers blood levels of beta-amyloid in elderly non-demented humans, and when given in early adulthood, prevents memory loss in mice bred to develop Alzheimer's disease in old age. Previous studies on rabbits also showed that caffeine may help to prevent Alzheimer's.

Researchers at the Florida Alzheimer's Disease Research Committee plan to start studies in humans to evaluate whether caffeine can prevent memory loss of early Alzheimer's disease. Other experiments by the same group show that caffeine may prevent memory loss by blocking the enzymes that make beta amyloid.

The amount of caffeine in two to five cups of coffee (200 to 500 milligrams) is probably safe, but more than five cups a day may cause insomnia, nervousness, irritability, nausea, anxiety, a fast or irregular heartbeat, headaches, breast pain or muscle tremors. People who have high blood pressure or narrowed arteries leading to the heart may be advised to restrict caffeine. However, the Nurse's Study showed that heavy coffee drinking is not associated with increased risk for high blood pressure. Unfiltered coffee raises blood levels of the bad LDL cholesterol and blood sugar levels after eating. Pregnant women are advised to restrict caffeine since it may cause miscarriage or low birth weight.

Many studies show that caffeine can improve mood, alertness and energy, prevent diabetes, Parkinson's disease, and liver cancer, decrease the risk of stroke and may help prevent skin cancer. It also increases endurance in athletes.

Protein for Muscle Recovery and Growth

Many athletes believe that they can grow larger muscles by taking protein supplements rather than by eating protein in ordinary foods. However, protein powders come from food, and extracts cannot be more efficient than the foods from which they are extracted.

All athletes train by stressing and recovering. They take a hard workout, damage their muscles, feel sore the next morning, and then take easy workouts until the muscles heal and the soreness goes away. The athlete who can recover the fastest can do the most intense workouts. Eating a high carbohydrate-high protein meal within a half hour after finishing an intense workout raises insulin levels and hastens recovery (Journal of Applied Physiology, May 2009). Another breakthrough study reported in the same issue shows that taking the high protein-carbohydrate meal before lifting weights does not hasten recovery.

Carbohydrate in the meal causes a high rise in blood sugar that causes the pancreas to release insulin. Insulin drives the protein building blocks (amino acids) in the meal into muscle cells to hasten healing from intense workouts. Muscles are extraordinarily sensitive to insulin during exercise and for up to a half hour after finishing exercise, so the fastest way to recover is to eat a protein- and carbohydrate-rich meal during the last part of your workout or within half an hour after you finish.

You can use either plant or animal sources of protein; both contain all of the essential amino acids necessary for cell growth.

There is also good data that creatine loading helps muscles recover faster. You get creatine from fish, poultry or meat, or creatine supplements. Your body can also make creatine from three amino acids found in both plants and animals: methionine, arginine and glycine. However, you get higher blood levels from supplements or animal protein sources. We do not know if taking the larger amounts of creatine in supplements is better than the amount found in meat, poultry or seafood.

Hip Fracture Usually Requires Hip Replacement

The most-feared injury among serious bicyclists is a broken hip. The femur hip bone is shaped like a shepherd's crook. The blood supply to the ball at the top of the hip bone comes in through the neck just below the ball. If the neck or ball are broken, the blood supply is usually shut off and the top of the hip bone dies. To prevent this from happening, fractures of the ball or neck of the hip bone are usually treated with immediate hip replacement. Try to avoid this drastic surgery by keeping your bones as strong as possible.

1) All exercise strengthens bones. Bicycling strengthens bones, but not as much as sports that exert greater forces on bones such as running or lifting weights. (Medicine & Science in Sports & Exercise, March 2009).

2) Exercise increases calcium absorption, which is necessary for strong bones. As I reported last week, even non-impact exercises such as swimming and cycling increase calcium absorption from the intestines by upregulating the calcium transporter genes. (American Journal of Physiology, Endocrinology and Metabolism, April 2009).

3) Those most likely to suffer broken bones during exercise are people who have low levels of vitamin D (Journal of Bone and Mineral Research, September 2006). When you lack vitamin D, ionizible calcium drops. This causes the parathyroid glands to put out large amounts of parathyroid hormone which takes calcium out of bones to weaken them and increase fracture risk.

4) High blood levels of parathyroid hormone (from vitamin D deficiency or any other cause) are a major risk factor for bone fractures during exercise (Bone, August 2005).

If you ever are unable to expose a few inches of skin to sunlight for at least 20 minutes four or five times a week, get a blood test called vitamin D3. If it is below 75 nmol/L, you need to take a vacation in a sunny place, or take at least 3000 IU of vitamin D per day until you can get some sunlight.

The Hygeine Hypothesis: Hot Debate

The Hygiene Hypothesis proposes that you need to have certain infections to have a healthy immune system. If you are not infected with various common germs, your immunity does not have the chance to practice killing germs and learning the difference between invading organisms and your own cells. For example, does Helicobacter pylori, the bacteria that causes stomach ulcers, also prevent diseases such as eczema? Nobody knows. Being infected with Helicobacter is associated with decreased risk for eczema (Journal of Epidemiology & Community Health, July 2007), but it is also associated with an increased risk for asthma (Gut, May 22, 2008).

Your immunity protects you from certain infections by searching out and killing foreign germs in your body. It does this by attacking surface proteins on invading bacteria and viruses. However, your immunity is not supposed to attack your own cells, so it does not attack cells that have the same surface proteins that your cells have. It may attack your lungs and cause asthma instead of attacking the bacteria that causes stomach ulcers. Your immunity may get so active with Helicobacter infections that it may attack your own skin to cause eczema.

The Hygiene Hypothesis has not been proven. It is just a hotly debated theory among doctors; only time will sort out the conflict and tell us if Helicobacter stomach infections help your immunity protect you from other infections. More on Helicobacter pylori
What should you do if your doctor tells you that you have blocked coronary arteries? A recent study shows that in people who have blocked arteries and diabetes, the chances of dying or having a major heart attack are the same whether they undergo surgical procedures (bypass or stents) or just take medication to treat cholesterol, blood pressure and diabetes. Death rate was also the same whether or not they took insulin (BARI 2D study, New England Journal of Medicine, June 10, 2009).

Patients who had bypass procedures had fewer heart attacks than those who had stents, even though both had the same chances of dying (also reported in the BARI-1 trial). I think that stents are less effective in preventing heat attacks because stents are foreign bodies placed in arteries that can increase chances of clotting, a major precipitating cause of heart attacks. That is why people with stents are given drugs to prevent clotting. Also, type 2 diabetics who were not given insulin had fewer blockages than those given insulin. I think that this is because high insulin levels constricts coronary arteries.

This is a very important study because the most common cause of a sudden heart attack is diabetes, and 80 percent of diabetics die of heart disease. More than one third of Americans will become diabetic and that number is projected to double by 2030.

If you have diabetes and blocked arteries, try to avoid surgery. If you need surgery, you may gain better protection from a bypass than from a stent. I also believe that you should try to control type II diabetes without insulin. Get a blood test called C peptide (which measures insulin production). If it is above one, try to avoid insulin. If it is below one, or you cannot get your HBA1C blood test (which measures cellular damage from diabetes) below 6.5, you may need insulin.

For everyone, I recommend: 1) A diet rich in fruits, vegetables, whole grains, beans, seeds and nuts. Restrict meat from mammals, and eat refined carbohydrates (sugar water and flour) only when exercising. 2) Exercise every day, and avoid overweight, smoking and more than two alcoholic drinks a day. 3) Keep blood levels of vitamin D3 above 75 nmol/L.

Surgery for Blocked Arteries Questioned

What should you do if your doctor tells you that you have blocked coronary arteries? A recent study shows that in people who have blocked arteries and diabetes, the chances of dying or having a major heart attack are the same whether they undergo surgical procedures (bypass or stents) or just take medication to treat cholesterol, blood pressure and diabetes. Death rate was also the same whether or not they took insulin (BARI 2D study, New England Journal of Medicine, June 10, 2009).

Patients who had bypass procedures had fewer heart attacks than those who had stents, even though both had the same chances of dying (also reported in the BARI-1 trial). I think that stents are less effective in preventing heat attacks because stents are foreign bodies placed in arteries that can increase chances of clotting, a major precipitating cause of heart attacks. That is why people with stents are given drugs to prevent clotting. Also, type 2 diabetics who were not given insulin had fewer blockages than those given insulin. I think that this is because high insulin levels constricts coronary arteries.

This is a very important study because the most common cause of a sudden heart attack is diabetes, and 80 percent of diabetics die of heart disease. More than one third of Americans will become diabetic and that number is projected to double by 2030.

If you have diabetes and blocked arteries, try to avoid surgery. If you need surgery, you may gain better protection from a bypass than from a stent. I also believe that you should try to control type II diabetes without insulin. Get a blood test called C peptide (which measures insulin production). If it is above one, try to avoid insulin. If it is below one, or you cannot get your HBA1C blood test (which measures cellular damage from diabetes) below 6.5, you may need insulin.

For everyone, I recommend: 1) A diet rich in fruits, vegetables, whole grains, beans, seeds and nuts. Restrict meat from mammals, and eat refined carbohydrates (sugar water and flour) only when exercising. 2) Exercise every day, and avoid overweight, smoking and more than two alcoholic drinks a day. 3) Keep blood levels of vitamin D3 above 75 nmol/L.

Burning During Exercise Differs from Muscle Pain After Exercise

The burning you feel in muscles during intense exercise is different from the burning and pain you feel after exercising. Burning during intense exercise is caused by the acidity from accumulation of lactic acid. When your muscles cannot get all the oxygen they need to convert food to energy during intense exercise, lactic acid accumulates in muscles, makes them more acidic, and the acidity causes a burning feeling. Excess lactic acid is cleared from the muscles within seconds after stopping exercise.

Lactic acid is good because it is the most efficient fuel for muscles during exercise. It requires less oxygen for energy than virtually all other fuels. Sodium bicarbonate (baking soda) neutralize lactic acid in muscles during intense exercise and helps athletes to exercise longer (Medicine & Science in Sports & Exercise, October 2006). Caffeine (the amount in four cups of coffee) reduces muscle burning during intense exercise (International Journal of Sport Nutrition and Exercise Metabolism, April 2009). More on lactic acid

Burning or pain eight to 24 hours after exercising is usually caused by damage to the muscles themselves. The longer you stay in the burn during exercise and the greater the force on your muscles during exercise, the greater the muscle damage. Most athletes train by taking a hard workout on one day, damaging their muscles and feeling sore on the next, and then going at low intensity for as many days as it takes for the soreness to disappear. When muscles heal from hard force on them, they become stronger. Athletes recover from hard exercise actively by exercising at low intensity. They rarely take days off. Exercising at low intensity during recovery makes muscles more fibrous which protects them from injury when they are stressed again.

Which Blood Pressure Number is More Important?

The higher number (systolic) measures pressure when your heart contracts, and the lower (diastolic) reading measures the pressure when your heart relaxes. A recent study followed people with high blood pressure to see which people developed heart attacks (Hypertension, May 26, 2009). The authors found that the best predictors for future heart attacks are the systolic (heart contraction) blood pressure and pulse pressure (the difference between systolic and diastolic blood pressures). Evidently the higher your blood pressure rises when your heart contracts, the more likely you are to have a heart attack. Normally, the aorta is supposed to widen when the heart contracts to send a large amount of blood to your arteries. Those with the stiffest arteries that do not widen with each heart contraction are the ones most likely to suffer heart attacks. More on interpreting your blood pressure numbers

Older People Need More Sunshine

A study from the University of Warwick in England shows that more time in the sun can help older people avoid diabetes and heart attacks (Diabetes Care, July 2009). They evaluated 3,262 people aged 50-70 years old in Beijing and Shanghai, China, and found that 94 percent were low in vitamin D and 42 percent of those had metabolic syndrome: abdominal obesity, high triglycerides, low HDL and high blood sugar levels. This is consistent with world- wide studies that show that as people age their skin atrophies, reducing their ability to make vitamin D from sunlight. Seniors also usually exercise less so they do not go outside as often. Since they are more susceptible to cold, they usually wear more clothing when they do go outside. Inadequate vitamin D increases risk for heart attacks, strokes, certain cancers, arthritis, auto-immune diseases and many other health problems.

A major function of vitamin D is to increase absorption of calcium from food. When vitamin D levels are low, body levels of ionized calcioum drop. This forces the parathyroid glands to increase production of parathyroid hormone that blocks insulin receptors, to raise blood sugar levels markedly and increase production of insulin. High levels of insulin constrict coronary arteries to cause heart attacks.

Vitamin D deficiency occurs when the concentration of D3 (25-hydroxy-vitamin D) is less than 75 nmol/L. If you are deficient, you need to expose skin to more sunlight or take at least 2000 IU of vitamin D3 per day. To address skin cancer concerns, protect the most frequently exposed areas, since it is cumulative life-long exposure to sunlight that increases risk for skin cancer. For most people, this means you should use sunscreen or wear clothing to cover your face, scalp, neck, tops of the ears, forearms and hands whenever you will be in the sun for more than 30 minutes.
More on vitamin D

Drop in Performance? Common Causes

1) The most common cause of a drop in performance in cycling, or any other sport, is overtraining: going hard when you should go easy. Hard-and- easy refers to intensity (speed and pressure on the pedals), not to total mileage. On one day, you ride very fast with your group, feel sore on the next day and go slowly for as many days as it takes for the soreness to go away. When the soreness goes away, you ride fast again. If you take hard workouts while your muscles are still sore you can cause chronic muscle soreness.

2) A second cause is a low-salt syndrome caused by sweat loss. The only mineral that you need in large amounts is sodium, common table salt. All athletes have to salt food heavily and use lots of salt. Your doctor can check for low-salt syndrome by having you take a very hard workout on one day, replenish your fluids, and then draw blood for sodium and chloride on the next morning. If you are worried about developing high blood pressure, check your blood pressure frequently.

3) The third most common cause is lack of vitamin D. Blood levels of vitamin D3 below 75 nmol/L can cause muscles to feel sore, particularly in the wintertime.

4) You can also fail to recover adequately from intense workouts if you do not carbohydrate- and protein-load within a half hour after you finish a workout. Your muscles are maximally sensitive to insulin during exercise and for up to a half hour after you finish exercising. Sugar taken within a half hour after you finish your intense workout will raise your blood sugar level enough to increase insulin levels. Insulin then drives protein into cells to help you recover faster.

5) Another cause of muscle soreness is not getting off your feet after intense workouts. Muscles recover fastest when they are not used. After intense workouts, lie down instead of sitting, standing or walking.

If you have had a marked drop in performance in your sport and none of these causes applies to you, you may need a medical evaluation.

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Muscle Soreness, Exercise Injuries and Vitamin D

When doctors don't know the cause of a patient's problem, they often give it a fancy name so you will believe they are giving you a useful diagnosis. A perfect example of this is "idiopathic inflammatory myopathy", which means you have chronic muscle soreness and your doctor doesn't know why. Researchers recently reviewed the effects of exercise on people with chronic muscle soreness and found that exercise is beneficial (Current Opinion in Rheumatology, 04/07/09):
• The muscles of many of subjects with this condition did not get a sufficient oxygen supply
• Exercise increases endurance-type fibers after a 12-week exercise program
• Creatine supplements plus an exercise program are more beneficial than exercise alone
• Intensive resistance training improves muscle strength and endurance
• Exercise reduces muscle soreness and possibly even muscle inflammation

I am now convinced that a leading cause of muscle soreness and slow-healing injuries is lack of vitamin D. All my life, I have suffered a series of baffling injures that usually occur in the winter and heal in the summer. For the entire winter of 2007-8, I was unable to exercise because of a non-healing hamstring injury and diffuse muscle soreness. Eventually I found that my vitamin D 3 level was 22 nmol/L (normal is greater than 75). I took the prescribed treatment of 50,000 IU of vitamin D twice a week and my muscles became so sore that I couldn't even walk. In the summer, the hamstring injury healed and the soreness disappeared. This winter I went to Florida and was able to train on my bicycle better than ever. In March I went back to wintery Maryland and the non-healing hamstring injury and soreness reappeared. This time I improved within 24 hours of taking 2000 IU of vitamin D twice a day. From my experience, I conclude that:
• my muscle soreness and non-healing injuries are caused by or worsened by low levels of vitamin D
• very high doses (50,000 IU) may increase muscle soreness
• lower doses of vitamin D (2000 to 4000/day) or daily sunlight exposure cured my muscle soreness and helped to heal my injuries

Dr. John Cannell of the Vitamin D Council quotes 14 studies that show that athletic performance improves in the summer months when sunshine is abundant, or with ultraviolet light exposure in winter.

If your muscles feel sore or you keep on being injured when you exercise, get a blood test called D3. If it is below 75 nmol/L, your problems may be caused by lack of vitamin D and be cured by getting some sunshine or taking at least 2000 IU each day of the very inexpensive vitamin D3.

Fructose More Likely than Glucose to Cause Diabetes

Sugared drinks are fattening because the human brain does not recognize liquid sugar as calories to make you eat less food. We get our sugar in drinks in three forms: glucose, fructose and sucrose (glucose and fructose bound together in a single molecule). Now a report from the University of California Davis shows that taking in too much fructose increases your risk for diabetes and heart attacks (Journal of Clinical Investigation, May 2009). Thirty-two overweight men and women drank 25 percent of their daily energy requirements in either fructose or glucose- sweetened drinks. In 12 weeks, both groups gained similar amounts of weight, but the people taking fructose-sweetened drinks had higher triglycerides and more abdominal fat, and were more resistant to insulin. All three factors precede diabetes which markedly increases risk for heart attacks.

The subjects were fed drinks that contained only glucose or fructose, so this study will not help you make good beverage choices. Virtually all sweetened beverages contain both fructose and glucose. Soft drinks sweetened with high fructose corn syrup have 55 to 58 percent fructose, while fruit juices and beverages sweetened with table sugar contain equal parts fructose and glucose. I recommend the following:

1) Take sugared drinks only when you are exercising or within a half hour of finishing exercising. All sugar-sweetened beverages increase risk for insulin resistance (Archives of Pediatric and Adolescent Medicine, April 2009). Contracting muscles are exquisitely sensitive to insulin and therefore help protect you from the high rise in blood sugar that causes the liver to make triglycerides, that block insulin receptors that cause the pancreas to release huge amounts of insulin that causes fat to be deposited in the belly.

2) When you are not exercising, quench your thirst with water or non-calorie beverages. Eat whole fruits rather than taking in your sugar in drinks. Fruit with its pulp does not cause as high a rise in blood sugar as do sugared drinks (including fruit juices). The higher your blood sugar rises, the more sugar sticks to the surface of cells, causing cell damage. An orange satisfies your daily requirement for vitamin C, has 2.8 grams of fiber and 64 calories from 17 grams of sugar. More on preventing diabetes

Caffeine Reduces Muscle Burning During Intense Exercise

Researchers at the University of Illinois report that 300 mg of caffeine (the amount in four cups of coffee) reduces muscle burning during intense exercise in both regular coffee drinkers and in those who do not drink coffee at all (International Journal of Sport Nutrition and Exercise Metabolism, April 2009). One of the researchers, Robert Motl, PhD, says that caffeine blocks spinal nerves that transmit pain messages to the brain. This means that people can exercise longer because they feel less pain.

Athletes take caffeine because they know it helps them to exercise longer. When muscles run out of their stored muscle sugar, they have to burn more fat which requires more oxygen. Lack of oxygen is the limiting factor in how fast and hard you can exercise over long periods of time. When you run low on oxygen, lactic acid accumulates in the muscles, which makes muscles more acidic, causing the burning that you feel in tired muscles. However, caffeine helps to delay the burning by causing muscles to burn more fat so they can preserve the sugar stored in muscles and you can exercise longer without accumulating large amounts of lactic acid.

Another interesting study from Iran showed that omega-3 fatty acids lessened delayed onset muscle soreness that occurs 48 hours after exercise in untrained men (Clinical Journal of Sport Medicine, March 2009).

Why Meat from Mammals is Risky

A study of more than 500,000 Americans over 40 shows that those who consume the equivalent of at least a hamburger a day have a 30 percent increased chance of dying during the next 10 years, mostly from heart disease and cancer. Cold cuts, sausage and other processed meats also increased the risk (Archives of Internal Medicine, March 2009). This agrees with many other studies showing that eating meat from mammals is associated with increased risk for heart attacks, arthritis, and several types of cancer. The study found that eating fish, chicken, turkey and other poultry decreased the risk of premature death.

Most authorities still attribute the high mortality in meat eaters to the saturated fats and cholesterol in meat. This makes little sense since 1) poultry is also a rich source of saturated fats and does not increase premature death, cancer or heart attacks; 2) people who eat a diet rich is saturated fats from palm, palm kernel and coconut oils are not at increased risk for premature death; and 3) eggs and shell fish are extremely rich sources of cholesterol and they are not associated with premature death. I believe that the most likely explanation for the increased risk for heart attacks and premature death in meat eaters is inflammation from the glycoprotein Neu5Gc; see my reports from November 9 and November 16, 2008

High Insulin = High Breast Cancer Risk

Women who have high levels of insulin are at high risk for developing breast cancer (Journal of the National Cancer Institute, January 2009). Insulin stimulates breast cells to grow. Women who are most likely to have high levels of insulin are those who are obese, store fat primarily in their bellies, do not exercise, eat lots of refined carbohydrates (sugar and flour), and lack vitamin D. Furthermore, people with diabetes who get cancer are 40 percent more likely to die earlier than cancer patients who are not diabetic (Journal of the American Medical Association, February 2007). Dr. Frederick Brancati of Johns Hopkins University in Baltimore combined the results of 23 studies involving about 125,000 people in 10 countries including the United States, Australia and the Netherlands. People with high blood sugar levels are at increased risk for cancers of the uterus, breast, colon, pancreas, endometrium, liver and bladder. Those with diabetes have a 76 percent higher risk of death from cancer of the uterus, a 61 percent higher risk for breast cancer, and a 40 percent increase for colon cancer. Furthermore, diabetics are at higher risk for heart disease, stroke, kidney damage and blindness.

Hard exercise should not reduce libido

If hard exercise or training causes you to lose interest in making love, get a medical check-up. If your doctor finds nothing wrong with you, you may be training too much. Most endurance athletes have normal blood levels of the male hormones, testosterone and dihydro-testosterone, and lose neither sexual desire nor sexual performance (Journal of Endocrinological Investigation, October 2008).

Endurance athletes who have low levels of testosterone usually have normal blood levels of LH and FSH, the brain hormones that control testicular production of testosterone. Defective testicular production of testosterone is usually associated with very high levels of brain hormones. That means that reduced sexual desire associated with endurance training is governed by the brain, not testicular damage, and is often part of an overtraining syndrome.

Training for competition is done by taking an intense workout on one day, feeling sore on the next, and going at reduced intensity for as long as it takes for the soreness to go away. Taking intense workouts when you feel soreness causes muscle injuries and fatigue that affects all your organ systems, including your sexuality. Once you develop an overtraining syndrome, it can take a very long time to recover. If this has happened to you, I recommend jogging slowly each day and stopping each workout immediately when your legs feel heavy or sore. When you feel better, you can start to train intensely again, but be sure to include slow recovery days in your training program.

Who should restrict salt? (and who should not?)

Most doctors recommend salt restriction for all their patients, even though many will not develop high blood pressure from high-salt intake and some may even be harmed if they restrict salt. Heavy exercisers lose so much salt that they have to take in lots of salt just to replace what they lose through sweat.

A study from China shows that people with metabolic syndrome are the ones who are most likely to develop high blood pressure from a high-salt diet and that high levels of insulin may cause the rise of blood pressure that is associated with increased salt intake (Lancet, published online March 2, 2009). Metabolic syndrome occurs when a person's cells lose their ability to respond adequately to insulin and blood levels of sugar rise too high. It is caused by eating too much refined carbohydrates, being overweight, not exercising, and lacking vitamin D and is characterized by storing fat primarily in the belly, having a thick neck, high blood triglycerides, low blood good HDL cholesterol, high blood sugar, and eventually liver damage and all the side effects of diabetes. People with metabolic syndrome had a greater rise in blood pressure with increased salt intake and drop in blood pressure with salt restriction. The more risk factors for metabolic syndrome a person had, the greater the rise and fall of blood pressure with changes in salt intake.

If you are concerned about your blood pressure, you can buy an inexpensive wrist cuff and check your blood pressure at bedtime. If it is below 120, you do not need to restrict salt. If you store fat primarily in your belly rather than your hips, your HDL is below 40, your triglycerides are above 175, or you have a blood sugar above 100 two hours after a meal or an HBA1C above 5.9, you probably should restrict salt and definitely should work to correct the causes of metabolic syndrome (described above).

Prolong life with exercise after age 50

Men who start or increase their exercise programs after age fifty live longer than those who remain at their present activity levels, according to a study in the British Medical Journal (March 2009). More than 2200 men were checked at ages 50, 60, 70, 77 and 82 years. The greater the increase in exercise duration over that span, the longer their lives were extended. The reduction in early death from increasing exercise was the same as for men who stopped smoking.

Lack of exercise is associated with obesity, diabetes, heart attacks, strokes, osteoporosis, and cancer. Exercising regularly more than halves your chance of dying prematurely (Archives of Internal Medicine, December 2007). Yet more than 50 percent of North Americans do not exercise.

Exercise prevents disease and increases life span by many mechanisms. The major benefit probably comes from the contracting muscles themselves. A high rise in blood sugars and fats after meals damages cells. When blood sugar levels rise too high, sugar sticks to the surface of cell membranes. Once there, it can never get off, eventually killing the cells and leading to blindness, heart attacks, strokes and the other consequences of uncontrolled diabetes. Contracting muscles draw sugar and fat so rapidly from the bloodstream that they usually prevent blood sugar levels from rising too high. This effect is maximized during exercise. The effect is maintained for about half hour after you stop exercising and gradually tapers off until it disappears after about 18 hours. That explains why you get maximum benefit by exercising every day (rather than three times a week), and why greater benefit is gained by exercising more intensely for longer durations. How to start an exercise program

Can't lose weight? New research on thyroid may solve your problem

Diets rarely help people to lose weight permanently, so exercise gives you your best chance to lose excess weight and keep it off. However, some people cannot lose weight, no matter how much they exercise. Researchers at the University of Pittsburgh showed that overweight people who do not lose weight when they follow an exercise program are likely to suffer from low thyroid function, and therefore should be able to lose weight if they take thyroid hormones (Medicine & Science in Sports & Exercise, February 2009). I think this is a very important study so this issue of the eZine is a little longer than usual.

When you eat, blood sugar levels rise. Your pancreas responds by releasing insulin into your bloodstream which drives sugar into cells where it can be used for energy. As you gain weight, fat cells fill with fat. This blocks insulin receptors so your cells cannot respond adequately to insulin and blood sugar rises to higher levels. This causes your pancreas to release even more insulin. Too much insulin can harm you. It acts on your brain to make you hungry, eat more and gain more weight. It constricts the arteries leading to your heart to cause heart attacks.

As I explained last week, muscles become extraordinarily responsive to insulin when you exercise so you need far less insulin to drive sugar from your bloodstream into cells. Insulin levels go way down with exercise, but the effect gradually tapers off in about 18 hours. So you have to exercise every day to maintain the benefit of lowered insulin levels, and overweight people who exercise every day usually lose weight.

However, some overweight people cannot lose weight no matter how much they exercise. This study shows that many of these people have low thyroid function which prevents the cells from responding to insulin and drives both insulin and blood sugar to very high levels.

Doctors do not diagnose low thyroid function by measuring thyroid hormone levels. Instead, they do a blood test called TSH that measures the brain's response to thyroid hormone levels. The brain produces TSH to stimulate the thyroid gland to make more thyroid hormone. TSH rises to high levels when the brain senses that there is not enough thyroid hormone in the body.

For many years, doctors have argued among themselves whether to treat people who have normal levels of thyroid hormones and very high levels of TSH (called subclinical hypothyroidism). This exciting new study shows that people who have high levels of TSH but have normal levels of thyroid hormone have muscles that do not respond to insulin adequately when they exercise. This means that they develop high levels of insulin and blood sugar, become overweight, diabetic, and often die of heart attacks.

If you are person who has extreme difficulty losing weight, ask your doctor to draw a blood test called TSH. If it is above 3.0, you probably will benefit from taking thyroid hormone. However, you must be careful not to take too much because overdoses of thyroid cause osteoporosis. Your thyroid dose should be adjusted to keep your TSH values between 0.3 and 3.0. Free weekly Fitness & Health eZine

Bone Density May Not Measure Bone Strength

A study from Manchester Metropolitan University in the UK shows that sprint cyclists have denser bones than long distance cyclists who have denser bones than sedentary control subjects (Medicine & Science in Sports & Exercise, March 2009). While cyclists have less dense bones than weight lifters and football players, they still have denser bones than people who do not exercise. The greater the force on bones during exercise, the denser the bone. So any type of exercise is good for your bones and a sedentary lifestyle is bad for bones.

When I reported on this study, several readers responded by quoting other studies that showed competitive cyclists have lower bone mineral density in their spines than moderately-active, aged-matched men (Medicine & Science in Sports & Exercise, February 2009; Osteoporosis International Reports, August 2003). These studies have been interpreted to mean that cycling increases risk for bone fractures beyond what you would expect from just falling off the bike.

I cannot find any studies showing that cycling weakens bones to increase fracture risk. Bone density is associated with bone strength, but does not measure it. The only way to measure bone strength is to see how much force it takes at break a bone. For example, birds have strong bones that are not very dense.

The theory that the act of cycling weakens bones flies in the face of our current understanding of bone metabolism. If indeed cyclists suffer from weak bones (and I do not believe that they do), the cause would be something other than riding a bicycle. Bones are constantly remodeling. Cells called osteoblasts bring in calcium to bones while cells called osteoclasts take calcium out. Any force on bones increases, and lack of force decreases, the rate of bone formation. Astronauts in space lose bone because lack of force blocks their ability to respond to Insulin Like Growth Factor-1 that stimulates bone growth (Journal of Bone and Mineral Research, March 2004). All competitive cyclists know that hammering on the pedals while pulling up on their handle bars puts tremendous force on every muscle and bone in their bodies, and this should stimulate bone growth.

Weight Training Benefits the Heart

Most authorities recommend both endurance and resistance exercise for heart health, even for people who have recovered from heart attacks. Now a study from The University of Athens in Greece shows how resistance exercise may help prevent heart attacks (Medicine & Science in Sports & Exercise, February 2009). Nine healthy, untrained male volunteers performed leg presses, with eight sets of six repetitions and three-minute rest intervals. One day later their blood fat levels were lower than normal after a high-fat meal. This shows that a single bout of weight lifting can prevent a high rise in blood fats one day later. A high rise in fat or sugar after meals increases risk for heart attacks. Exercising and exercised muscles help to remove sugar and fat from the bloodstream and this effect can last as much as twenty-four hours.

Diabetes Can Be Prevented and Cured

In 2007, 233,619 Americans died from diabetes. 60 percent of the U.S. population over 65 suffers from diabetes or pre-diabetes and most have not even been diagnosed (Diabetes Care, February 2009). Four important reports should spur you to act if you have any of the risk factors for diabetes: “Diabetes Doubles Your Chances of Suffering from Dementia” (Diabetes, January 2008); “HBA1c Test Predicts Which Diabetics Will Lose Brain Function” (Diabetes Care, February 2009) “Rigorous Workouts Lasting as Little as Three Minutes May Help Prevent Diabetes by Helping to Control Blood Sugar” (BioMed Central Endocrine Disorders, February 2009); and “Exercise Capacity Predicts Which Diabetics Are at High Risk for Dying Prematurely” (Diabetes Care, March 2009).

If you have any combination of the following risk factors, suspect that you may be diabetic and check with your doctor:
* store fat predominantly in your belly, rather than your hips
* family history of diabetes
* overweight
* exercise less than three times a week
* high blood pressure
* HDL cholesterol lower than 40 mg/dL
* triglyceride level greater than 150 mg/dL
* history of diabetes during pregnancy or birth to a 9-pound baby
* thick neck
* polycystic ovary syndrome
* dark, thick skin around neck or armpits
* history of blood vessel disease to heart, brain, or legs
* HBA1C greater than 5.8
* fasting blood sugar greater than 100
* sugar two hours after eating greater than 100
* member of a high-risk ethnic population (e.g., African-American, Hispanic/Latino- American, American Indian, Alaskan Native or Pacific Islander)

You can become non-diabetic by losing weight, exercising, avoiding refined carbohydrates, and treating vitamin D deficiency so D3 blood test is greater than 75 nmol/L. More on diagnosis and treatment of diabetes

Heart Attack Prevention: More than Cholesterol

Seventy-two percent of patients admitted in American hospitals for their first heart attack have blood cholesterol levels in the normal range (American Heart Journal, January 28, 2009). This means that the cholesterol guidelines are missing the majority of patients who have heart attacks because either 1) the guidelines are not low enough or 2) something other than a bad LDL cholesterol is causing most heart attacks in the United States.

Many good studies support the present guidelines that everyone should get their bad LDL cholesterol below 100. However, it now appears that some other risk factor must be affecting many people who suffer heart attacks. In November 2008 I reported on the Jupiter study which showed that statin drugs caused people with normal cholesterol but with high C-reactive protein levels to suffer 54 percent fewer heart attacks, 48 percent fewer strokes, 46 percent fewer angioplasties or bypass operations and 20 percent fewer deaths from any cause than those taking placebos (NEJM, November 9, 2008). Statins are known to reduce inflammation as well as to lower LDL cholesterol. A C-reactive protein test (CRP) measures inflammation. Inflammation is caused by anything that keeps your immunity active such as chronic infections or anything that damages tissue such as smoking, having high cholesterol or high blood pressure.

I also reported a theory to explain why eating mammal meat causes inflammation and is associated with increased risk for premature death, cancers and heart attacks. Meat contains a molecule called Neu5Gc that humans do not have, so the immune system of humans attacks this protein as if it was an invading germ and eventually attacks the host itself to destroy the blood vessels and increase risk for heart attacks and strokes. On the basis of this theory I strongly recommend avoiding meat from mammals, including beef, pork and lamb. Today, the best strategy for avoiding a heart attack includes lowering LDL cholesterol by avoiding saturated and partially hydrogenated fats and refined carbohydrates; and eating plenty of fruits, vegetables, whole grains, beans, seeds and nuts. Reduce inflammation by treating chronic infections and high blood pressure, avoid being overweight, smoking and eating meat. Exercise regularly, and work up gradually to a program that includes some intense exercise. Your doctor may recommend statins both to lower cholesterol and to control inflammation.

Exercise Protects against Inflammation

Researchers from Ataturk University in Turkey showed that hard exercise protects you from inflammation by raising blood levels of the antioxidants superoxide dismutase, glutathion peroxidase and glutathione S-transferase (The Journal of Sports Medicine and Physical Fitness, September 2008). During vigorous exercise, food exposed to oxygen is converted to energy by transferring electrons from one chemical to another. If the transferred electron ends up on hydrogen, it is converted to water and is harmless. If it ends up on oxygen, it forms free radicals that can damage your genetic material and cause cell damage. To protect you, your cells produce antioxidants. Exercise protects you from free radicals by causing your cells to produce large amounts of antioxidants.

Greater Endurance with Aging

I’m 74 years old and ride my bicycle more than 200 miles per week, often in pace lines with younger riders. I have noticed that younger riders can easily pull away from me in short bursts, but I keep coming back on them and seem to be better able to keep up with their accelerations as the ride progresses.

The latest issue of Exercise and Sports Sciences Reviews (January, 2009) reviews the entire world’s literature to show that endurance improves as you age. Wow!

The maximal muscle contraction force occurs when you do a single muscle contraction with all your might. Even though older people are not as strong as younger ones, many studies show that they can retain maximal force after many contractions far longer than younger people can.

Here’s the theory and evidence to explain why aging improves endurance. Muscles are made up of millions of individual fibers just as a rope is made up of many different threads. Each muscle fiber is enervated by a single nerve. As you age, you lose nerves throughout your body and when you lose the nerve that enervates a specific fiber, you also lose that muscle fiber.

Muscle fibers are classified as type I endurance fibers and type II strength and speed fibers. With aging, you lose far more nerves that enervate the strength and speed fibers than those that enervate the endurance ones. So, with aging, you lose strength but you retain a greater proportion of endurance fibers.

Muscle fatigue comes from the accumulation of waste products that occurs while food is converted to energy to power your muscles. Scientists can measure fatigue by measuring the accumulation of acid (H+), Phosphate (Pi) and protonated phosphate (H2PO4) in muscle. With the same percentage of their maximal muscle force, older people accumulate far lower levels of these end products than younger people do. Therefore even though older people are weaker, they can maintain their forceful contractions far longer than younger people can and they have greater endurance. This exciting recent data will encourage me to train even harder.
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