New Theory on Recovery from Workouts

The soreness that you feel 8 to 24 hours after an intense workout is caused by a tearing of the muscle fibers. The fastest way to get muscles to heal is to have your body produce lots of insulin and also provide a supply of protein to repair the damaged tissue. We have known for a long time that insulin drives sugar into cells for energy. Now we know that it also drives protein building blocks called amino acids into the muscle cells to help them heal faster. A study from New Zealand shows that protein loading immediately after exercise helps cyclists recover faster so they can ride harder for several days after an intense workout (Physiologie Appliquée, Nutrition et Métabolisme, February 2008).

On the surface of muscle cell membranes are little hooks called insulin receptors. Before insulin can do its job of driving sugar and protein into cells, it must first attach to these receptors. Hard exercise markedly increases insulin's ability to attach to insulin receptors and therefore makes insulin more effective. However, this increased response of insulin to exercise lasts only during exercise and for perhaps half an hour after exercise. An hour after you finish exercising, you have lost this added sensitivity of insulin receptors to insulin. So to help muscles recover faster, you need to take a carbohydrate source during a hard workout and immediately after you finish. Any source of carbohydrates will be broken down into simple sugars that call out insulin. Then, as soon as possible after your workout, you should eat any source of protein to supply the amino acids needed to heal damaged muscle tissue.

Entrepreneurs will probably use this information to promote various protein drinks and supplements, but you will get the same results with any sugared drink and any food or drink that contains protein. Soda and cheese or your favorite sports drink and shrimp or nuts will work just fine. More

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Low maximum heart rate signals fitness

No matter how hard I exercise, my heart rate never gets as high as my husband's. Should I be concerned? No; it may just mean that you are in very good shape. Researchers at Liverpool John Moores University in England showed that athletes have much lower maximum heart rates than sedentary people and that female athletes have lower maximum heart rates than male athletes (International Journal of Sports Medicine, February 2008).

Most exercisers should not even bother with heart rate calculations. Your training heart rate occurs when you exercise vigorously enough to make your body require more oxygen. You can tell when this happens because you will start to breathe deeper and faster, raising your shoulders with each breath. Once or twice a week, you should try to exercise intensely enough to increase your need for oxygen. If you feel uncomfortable, you should slow down. Non-athletes do not ever need to exercise so vigorously that they become severely short of breath. More

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Salt restriction hinders exercisers

Most doctors recommend low salt diets because of the evidence that taking in too much salt can cause high blood pressure, a major risk factor for heart attacks and strokes. However, this may not be good advice for dedicated exercisers. If you exercise heavily and restrict salt, you will not replace the salt you lose through sweating, which can cause high blood pressure as well as fatigue, cramps and muscle pain. When the body is low in salt, the adrenal glands produce large amounts of aldosterone and the kidneys produce renin, which constricts arteries and can raise blood pressure.

Researchers at Albert Einstein College of Medicine showed that people on low-salt diets are actually more likely to suffer heart attacks than those on high salt diets (Journal of General Internal Medicine, June 2008). They analyzed data from the Third National Health and Nutrition Examination Survey (NHANES III) of American adults. Dr. Hillel W. Cohen, lead author of the study, stated, "Our findings suggest that for the general adult population, higher sodium is very unlikely to be independently associated with higher risk of death from heart attacks."

Many years ago, when I was competing in marathon races, I decided to try a low-salt diet. I was surprised to find that my blood pressure rose from a normal 120/ 80 to as high as 160/80, and I suffered severe fatigue and frequent injuries. When I added salt back into my diet, my blood pressure went down to normal and I was able to train and compete again. This is why I recommend a relatively high-salt diet for exercisers. If you decide to increase your intake of salt, get a blood pressure cuff and check yourself for a month. If your blood pressure goes above 120/80, you may have added too much salt. Also, if you stop exercising because of an injury or for any other reason, be sure to cut out the extra salt to keep your blood pressure under control. More

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Fewer Omega-6's May Reduce Cancer Risk

Researchers at UCLA show that reducing intake of corn oils helps to prevent prostate cancer in mice (Cancer Research, April 15, 2008). Corn oil and other vegetable oils are extremely rich sources of omega-6 fatty acids.

Fats are classified by their chemical structure into omega-3s, omega-6s, and omega-9s. Omega-6s cause your body to produce prostaglandins that turn on your immunity to cause inflammation, while omega-3s turn down your immunity to reduce inflammation.

Your immunity is supposed to be good for you. When a germ enters your body, your immunity produces white blood cells and proteins called antibodies that attack and kill the germ. After that germ is gone, your immunity is supposed to stop making so many immune cells and proteins. If it remains active, your immunity attacks your own body to damage tissue and increase risk for heart attacks, certain cancers, and diabetes; it can also worsen existing diseases such as some types of dementia, asthma or psoriasis.

For more than 2 million years, humans have eaten diets that have a ratio of omega-6s to omega-3s of about two to one. However, over the last 100 years, humans have added extracted vegetable oils to other foods that they eat and increased the ratio to 12 to one and perhaps as high as 20 to one. This increase in the ratio of omega-6s to omega-3s is a cause of inflammation. The increase in omega-6's has come primarily from vegetable oils that are added to baked, fried and other prepared foods. Omega-3s oils are relatively unstable so they are not found in most prepared foods.

Good food sources of omega-3's include seafood and beans, whole grains, nuts and other seeds. We do not know if changing the ratio of omega-6s to omega-3s will help to prevent cancers in humans, but several studies show that they appear to both prevent and slow cancers in animals.
More on omega-3s and omega-6s

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Breast Cancer Risk Lower with Exercise

A recent study from Washington University School of Medicine in St. Louis shows that exercise starting during adolescence can protect girls from breast cancer (Journal of the National Cancer Institute, May 2008). Researchers tracked 65,000 nurses who answered questionnaires about exercise. Within six years, 550 were diagnosed with breast cancer before menopause. Those who exercised regularly as teens were 23 percent less likely to develop premenopausal breast cancer than their sedentary peers. Ages 12 to 22 appear to be the most important time to use exercise to help prevent breast cancer.

Higher estrogen levels increase risk of breast cancer. Exercise lowers estrogen by reducing body fat. Fat cells make estrogen, and after the menopause fat cells are the principal source of estrogen. Other factors that increase breast cancer risk are also related to higher estrogen levels: starting to menstruate at an early age, late onset of menopause, taking estrogen after menopause, and being overweight.

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Kidney function improved by exercise

We already know that exercise helps to prevent heart attacks, strokes, diabetes, obesity and certain cancers, and may extend life span. Now a report from Italy shows that exercise may also help to prevent kidney damage that occurs with aging (Clinical Journal of Sport Medicine, May 2008).

Doctors measure kidney function by calculating the ability of the kidneys to rid the body of a breakdown product of metabolism called creatinine. Regular exercisers have lower blood creatinine levels and also have kidneys that are better able to clear creatinine from the bloodstream as measured by a test called Glomerular Filtration Rate (GFR).

According to this study, professional bicycle racers have better kidney function than both sedentary people and recreational cyclists. This is very interesting because professional cyclists dehydrate themselves with almost every workout, in spite of the huge amount of fluid they consume. The researchers found that frequent dehydration accompanied by drinking large amounts of water did not cause kidney damage. This repeated stress on the kidneys may even explain why the professional cyclists had better kidney function than the less-active participants.
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Ibuprofen reduces risk of Alzheimer's

Researchers at Boston University School of Medicine followed 250,000 veterans over the age of 55 years and showed that taking ibuprofen for five years was associated with a 40 percent reduction in the development of Alzheimer's disease (Neurology, May 2008).

Alzheimer's disease is associated with the deposition of tangled webs of protein in the brain. Several previous studies show that ibuprofen reduces these protein deposits in the brains of animals. A leading theory on the cause of Alzheimer's disease is that a person's immunity attacks the brain to cause dementia. Ibuprofin reduces inflammation, the body's response to an overactive immunity. Another study in the same issue of Neurology showed people that with shorter arms and legs may be at a higher risk for developing dementia later in life. More on preventing dementia

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