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.

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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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Cold or Fever: Should You Exercise?

Exercise may actually be beneficial when you have a cold. However, it's probably better to stop exercising altogether if you have a fever with aching muscles. When you exercise, your heart has to pump blood to your muscles to supply them with oxygen. It also must pump blood from your muscles to your skin where the heat is dissipated. When you have a fever, your heart has to work harder to get rid of extra heat.

You risk injury if you exercise when your muscles hurt at rest. When muscles are damaged, they release enzymes from their cells into the bloodstream and they fill with blood from broken blood vessels. One study reported markedly increased muscle damage during relatively minor exercise during an infection, with blood tests showing increases in muscle enzymes and ultrasound tests demonstrating hemorrhage into the muscles. You will not lose much conditioning if you take off a few days.

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How Exercise Preserves Brain Function

Dr. Yu-Min Kuo, of the National Cheng Kung University Medical College in Taiwan, has shown how exercise helps to preserve brain function as you age (The Journal of Applied Physiology, November 2008). Dr Kuo trained mice to run daily for five weeks on wheels at 70 percent of their capacity. They started to exercise at 8, 12 and 24 months of age. These ages are equivalent in humans to ages of 40, 60 and 90 years.

The mice that exercised every day grew 2.5 times more new brain cells than those who did not exercise, and these new nerves helped them to learn and memorize new tasks. The increase in brain cells came from increased production of signaling molecules that promote brain cell growth.

However, the mice that started exercise in early middle age (equivalent to age 40) did much better than mice that did not start exercising until later middle age (equivalent to age 60). This would indicate that the capacity of exercise to help you maintain intelligence decreases after middle age.

When you are young, your body continuously creates new brain cells. As you age, your brain loses its ability to regenerate new nerve cells. This is why you gradually lose some of your ability to remember and learn. We don’t know if Dr. Kuo’s results would be found in humans, but his study should encourage people to start exercising while young and continue throughout their lives.

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Farmed Tilapia and Catfish are More Like Chicken than Fish

Fish are heart-healthy foods because they usually have high levels of omega-3 fatty acids and low levels of omega-6's.. However, researchers at Wake Forest University School of Medicine show that farm-raised tilapia and catfish contain less than one-eighth the amount of omega-3's found in farmed salmon or trout. The tilapia and catfish also had much larger amounts of omega-6 acids than salmon or trout. The ratio of omega-6 to omega-3 in tilapia and catfish averaged 11 to one, about the same as that of chicken (Journal of the American Dietetic Association, December 2008).

A crucial part of a healthful diet is the ratio of omega-6s to omega-3s. Your immunity is supposed to be good for you by killing gems before they can harm you. However, if your immunity stays active, it starts to attack your own body to increase risk for heart attacks, certain cancers and even asthma and some types of arthritis. Omega-3 fatty acids produce prostaglandins that turn down your immunity to help prevent inflammation and the health problems it can cause. Omega-6 fatty acids promote inflammation. A major explanation for the high heart attack rate in North Americans is the high ratio of omega-6s to omega-3s in the diet that contains lots of omega-6s from vegetable oils and low amounts of omega-3's found in fish and seeds.

Few species of fish can grow and thrive on a diet of corn and plant oils. Salmon, trout and most other farmed fish must be fed fish meal and fish oils, which are good sources of omega-3's. However, tilapia and catfish can be raised on corn alone. Since corn-fed tilapia are inexpensive and abundant, they are the fifth most popular fish in America and are widely used for fish sticks, fish burgers and artificial crab (surimi). These are perfectly good foods, but to get the full benefit of omega-3's in seafood, choose oily fish such as salmon, trout, tuna, sardines, anchovies, mackerel or herring. More on omega-3's

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Nuts Combat Metabolic Syndrome (Syndrome X)

Nuts are concentrated sources of fat and calories, but they are high in monounsaturated fats which are healthful. A new study from Spain shows that adding nuts to a Mediterranean diet helps to reverse Metabolic syndrome, defined as having three or more of the following: 1) abdominal obesity, 2) high triglycerides, 3) low HDL (good) cholesterol, 4) high blood sugar and 5) high blood pressure. More than 20 percent of North Americans have metabolic syndrome and are at high risk for diabetes. Many of these people will die prematurely, usually from a heart attack.

This study involved 1,200 men and women from 55 to 80 who followed one of three diets for one year. Sixty-one percent of the study group had metabolic syndrome. The first group followed a low-fat diet that reduced all types of fats. The second group ate a Mediterranean diet with at least four tablespoons of olive oil a day. The third group ate the Mediterranean diet with extra nuts. At the end of the study all three groups had improved, but those eating nuts had far fewer of the factors that make up metabolic syndrome. Most did this without restricting calories or losing weight, but they were able to reduce belly fat and lower cholesterol and blood pressure (Archives of Internal Medicine, December 2008).

Fats are classified by their chemical structure into saturated, polyunsaturated and monounsaturated. Monounsaturated fats found in olives, avocados and many nuts and seeds help to prevent heart attacks. Before the bad LDL cholesterol can damage arteries, it must first be oxidize in your bloodstream. LDL cholesterol made from monounsaturated fats is highly resistant to oxidation, so it helps to prevent damage to arteries that can lead to a heart attack. The diet I recommend includes plenty of the good fats found in nuts, seeds, beans, whole grains, olives, avocados, fish and shell fish.

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Understanding Delayed Muscle Soreness

If you exercise properly, you are supposed to work hard enough to damage your muscles so they feel sore on the next day. This is called delayed-onset muscle soreness. You should then exercise at reduced intensity for as many days as it takes for the soreness to go away.

An article from St Mary’s University College in New Zealand reviews scientific studies on exercise-induced muscle damage (Sports Medicine, December 2008). When muscles feel sore from exercise, they are swollen and leak proteins from inside their cells into the bloodstream, and they cannot generate their usual force. You really have no choice. You must put far less pressure on sore muscles or you will injure them, delaying recovery and your ability to exercise intensely again.

Sore muscles heal faster if you take the next day off, but exercising gently during recovery will make your muscles more fibrous so they can withstand more pressure when you take your next intense workout.

Eating foods with protein and sugar within four hours after you finish a hard workout helps muscles recover faster. The sugar raises insulin levels which helps to drive protein into the muscle cells to promote healing.

Aspirin and nonsteroidals such as ibuprofin may help reduce muscle soreness, but they can delay healing. Stretching and massage make your muscles feel better but there is little evidence that they make you recover faster. Studies of electrical muscle stimulation and cold therapy (ice packs) are so inconsistent that most exercise researchers do not recommend them. On the other hand, virtually everyone agrees that each bout of intense, muscle-damaging exercise followed by reduced intensity exercise makes muscles stronger.

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