Calcium and Vitamin D Pills Questioned

The prestigious Institute of Medicine issued a report recommending that adult North Americans need only 1,000 milligrams of calcium and 600 IU of vitamin D per day, and that most people do not need supplements. Taking too much calcium can cause kidney stones, and taking calcium without also taking vitamin D may increase risk for heart disease. Very large amounts of vitamin D may increase risk for fractures. The authors believe that adolescent girls may be the only group that is getting too little dietary calcium (Report from the Institute of Medicine of the National Academies, November 30, 2010).

Those of you who have read my newsletters for the past few years know that I am very concerned about vitamin D deficiency. However, I do not recommend taking vitamin D pills unless your blood level of vitamin D is less than 75 nmol/L (30 ng/L). How have scientists decided that your blood level of vitamin D should be above 75 nmol/L? A major function of vitamin D is help your body absorb calcium. When you lack vitamin D, ionized blood calcium levels drop. This causes your parathyroid gland to become overactive and produce too much parathyroid hormone. Too much parathyroid hormone forces calcium out of bones to weaken them. The lowest level of vitamin D that keeps parathyroid hormone at normal levels is 75 nmol/L. If your blood level of vitamin D3 is less than 75 nmol/L, you need extra sunlight or to take at least 2000 IU of vitamin D3/day until you reach a normal level.

Hundreds of studies show that people with low blood levels of vitamin D are more likely to suffer many different cancers, heart attacks, strokes, diabetes, osteoporosis, bone fractures, autoimmune diseases, decreased immunity, and so forth. However, except for weakened bones, these are associations, not cause-and-effect. To prove causation, we need studies showing that giving pills to raise blood levels of vitamin D prevents or cures cancers, diabetes, heart disease and other conditions. So far this has been done only for bone diseases, fractures and prevention of influenza. It may be that vitamin D deficiency is only a marker for other factors, such as lack of outdoor exercise, that contribute to all of these diseases. If this is true, then taking vitamin D pills would not correct the underlying problem.

Researchers at Emory University studied vitamin D status in twins living in different North American locations. They concluded that vitamin D deficiency runs in families and is mostly genetic (American Journal of Clinical Nutrition, December 2010).

Children Can Lift Weights at Any Age

Lifting weights before puberty makes children stronger and has not been shown to stunt growth or damage the growth plates in their bones (Pediatrics, November 2010). The older the child, the greater the gain in muscle strength from resistance training. The more and the heavier weights they lift, the stronger they became. A surprising finding was that children did not show a significant increase in strength when they enter puberty, a time when their testosterone levels rise significantly.

The best time for future competitive athletes to start training is before they reach puberty. Having large strong muscles makes you a better athlete, and starting training before puberty enlarges the bones that are used primarily in that sport. Muscles growth is limited by the size of the bones on which they attach. The larger the bone, the stronger the muscle. Children who start to play tennis before they go into puberty have larger bones in the arm that holds the racquet. They also have larger bones in their tennis arm than those who start to play tennis later in life. The larger and stronger your muscles, the harder you can hit a tennis ball. As little as four weeks of hard exercise in growing animals increases bone mass (Medicine & Science in Sports & Exercise, October 2000). This suggests that children who start training while they are still growing will have an advantage over athletes who start training after puberty, because having larger bones allow a person to grow larger muscles.

Lifting weights during growth has not been shown to prevent children from growing to their full potential height. Bones grow from epiphyses, growth centers that are the weakest part of bone, but strength training during growth has not been shown to damage these growth centers. Children who lift weights in supervised programs do not suffer more injuries than adults. With increased strength comes increased speed and increased coordination in movements requiring strength.

In most sports, the strongest athlete wins. Weightlifter Naim Suleymanoglu of Turkey, who won three Olympic gold medals and is probably the greatest weightlifter who ever lived, started lifting weights when he was eight years old. Muscles can only grow to be as strong as the strength of the bones on which they attach, so people with the biggest bones are the ones who can grow the biggest muscles.

Children who lift weights do not grow muscles as large as older people do. Muscles are made up of thousands of individual muscle fibers. Each muscle fiber is innervated by a single nerve, although each nerve can innervate many muscle fibers. When you contract a muscle, you contract only a few muscle fibers at one time. With strength training, children learn to contract more muscle fibers at the same time, so they become stronger primarily by being able to contract more muscle fibers. Adults commonly grow larger muscles.

There is great concern that children may be subjected to unreasonable coaches and inconsiderate parents who place athletic training above the child's own needs and desires. In one study from Southern California, 90 percent of female cross country runners who stated running before they were nine stopped running before they reached high school. In 1967, I started competitive long distance running for young children and was the first national chairman of the age group committee of the Amateur Athletic Union and The Road Runners Club of America. Children came from all over the United States and Canada to compete in age group cross country and track running. Many were coached by experienced runners and trained with the same types of workouts used by the older runners. These children rarely suffered from injuries, and when they were injured, they recovered faster than the older runners. However, the real problem of starting children in competition at an early age is burnout. My own son started serious running when he was five and ran a mile in four minutes and 52 seconds when he was nine. He stopped competitive running when he was eleven.

The concern about serious athletic training for young children is more mental than physical. Children should not begin serious athletic training unless they want to do it. They should take days off from training when they want to, and their coaches and parents must allow them to be children.

Air Conditioning Helps Recovery

A study from the University of Montana in Missoula shows that athletes recover from hard workouts faster in room temperatures of 72 F than in 91 F (International Journal of Sports Medicine, August 2010). Nine male participants completed one- hour time trials at 91 degrees F, followed by recovery in rooms at 91 degrees F or 72 degrees F. They were given recovery carbohydrate beverages at zero and two hours. Four hours after the time trial, the athletes in the air conditioned room had much higher muscle glycogen levels (105 vs 88 mmol/kg).

Intense exercise causes the soreness that signals muscle damage that is necessary for muscle growth. Intense exercise also depletes your muscles of glycogen. The faster you replace glycogen, the quicker you recover and the sooner you can exercise intensely again. Athletes who can take the most intense workouts with adequate recoveries improve the most. This study shows that in hot weather, you will replace used-up muscle glycogen faster in air conditioning than at higher temperatures.

Training in Heat to Improve Performance

A paper from the University of Oregon shows that training in the heat can improve racing performance in the cold (Journal of Applied Physiology, October 2010). Twenty competitive cyclists continued their regular training. In addition, they completed ten 1.5-hour training sessions at 50 percent of their maximum effort (VO2max). However one group rode in a lab heated to 104 degrees, the other group rode in 55 degree lab.

The cyclists who were heat acclimated improved their time-trial performance four to eight percent, while the cold-trained group did not improve.

Training in the heat makes you a better athlete because it cools your body better. Since more than 70 percent of the energy used to drive your muscles is lost as heat, the harder you exercise, the more heat you generate and your body temperature rises. With each increase in body temperature, your body requires more oxygen to turn food to energy. Since lack of oxygen is the limiting factor to how fast you move and how much power your muscles generate, any increase in body temperature slows you down.

Training in the heat increases blood volume so you have more blood available to carry heat from hot muscles to your skin where the heat can be dissipated. sweating begins earlier and is more profuse to cool your skin, and the heart pumps hot blood to the skin faster. All these factors lower body temperature.

Some athletes may decide to heat train by wearing plastic or thermal suits. It could be dangerous because it prevents sweat from evaporating and a person could overheat and pass out or even die. You can help protect yourself from heat stroke by knowing the progressive signs of rising body temperature. See my report on the dangers of swimming in warm water

Ice Delays Recovery from Injuries

More than 30 years ago I coined the term RICE (Rest, Ice, Compression, Elevation) for the acute treatment of athletic injuries. Now a study from the Cleveland Clinic shows that one of these recommendations, applying ice to reduce swelling, actually delays healing by preventing the body from releasing IGF-1 (Insulin-like Growth Factor-1), a hormone that helps heal damaged tissue (Federation of American Societies for Experimental Biology, November 2010).

When germs get into your body, your immunity sends cells and proteins into the infected area to kill the germs. When muscles and other tissues are damaged, your immunity sends the same inflammatory cells to the damaged tissue to promote healing. The response to both infection and tissue damage is the same. Certain cells called macrophages rush to the damaged tissue to release IGF-1 which helps heal muscles.

Healing is delayed by cortisone-type drugs, nonsteroidal anti inflammatory drugs such as ibuprofen, applying cold packs or ice, and anything else that blocks the immune response to injury. Now the treatments for an acute injury include Rest (stop exercising), Compression and Elevation (to reduce swelling), but no ice.

Soap Removes Vitamin D

Vitamin D deficiency is very common, even among athletes who spend a lot of time outdoors. Seventy-three percent of athletes tested in a private practice were vitamin D deficient (Clinical Journal of Sport Medicine, September 2010). If you spend a lot of time in the sun and still have low vitamin D, you may have a genetic susceptibility to vitamin D deficiency, or you may just use too much soap (The Lancet, published online June 9, 2010).

Your epidermis (outer layer of skin) makes cholesterol and converts it to 7-dehydrocholesterol. Some 7-dehydrocholesterol remains in the skin, but much of it is secreted in oil to the skin's surface. There exposure to ultraviolet light converts it to previtamin D3 (cholecalciferol). Since both skin oil and vitamin D3 are fat soluble, and not water soluble, a shower does not wash away vitamin D, but using soap does. To preserve vitamin D, use soap where you need it, but don't lather it over your whole body.

Fur and feathers in some animals block UV rays from skin, but their skin oils carry 7-dehydrocholesterol to their hair and feathers where UV light converts it to previtamin D3. They get their vitamin D by licking and grooming their hair or feathers.

Danger of Swimming in Warm Water

We don't yet know why US swimmer Fran Crippen died in Dubai, but the most likely cause is heatstroke. He disappeared in 86 degree water barely 400 meters from the finish of the six-mile World Cup race.

You are far more likely to suffer heart stroke racing in water temperatures above 80 degrees than you are to suffer heat stroke at any temperature on land. During exercise, more than 70 percent of the energy used to drive your muscles is lost as heat, so your heart has to pump extra blood from your hot muscles to your skin where you sweat. When you exercise on land, sweat evaporates and cools your skin to dissipate the heat. You produce sweat when you swim, but the sweat cannot evaporate to cool your body.

Almost all cases of heat stroke occur when you suddenly increase the intensity of your exercise, like the finishing sprint of a race. Nobody should ever die of heat stroke because your body sends you warning signals as your temperature rises. In 1965, I almost died from heat stroke in an unimportant local running race in Arlington, Virginia. I am still embarrassed by my stupidity because I ignored all the warning signs as my temperature continued to climb. First your muscles are affected, then your circulation and then your brain. As your temperature starts to rise, your muscles feel like a hot poker is pressing against them. It is normal for intense exercise to make your muscles burn, but hard exercise does not cause painful burning that feels like fire. Furthermore, the burning of hard exercise is relieved by slowing down. The muscle burning of impending heat stroke does not go away when you slow down.

As your temperature rises further, the air that you breathe feels like it's coming from a furnace and no matter how rapidly and deeply you try to breathe, you can't take in enough air. When you exercise intensely, you can become very short of breath, but the air you breathe will not burn your lungs. Burning in your lungs, not relieved by slowing down, signals impending heat stroke. When you feel that the air is so hot that it burns your lungs, stop exercising. Your heart cannot pump enough blood from your exercising muscles to your skin so heat is accumulating rapidly and your temperature is rising rapidly. Your temperature is now over 104 and continuing to exercise will raise your body temperature even further and it will start to cook your brain. Your head will start to hurt, you'll hear a ringing in your ears, you may feel dizzy, you may have difficulty seeing and then you will end up unconscious. Your temperature is now over 106 and your brain is being cooked like an egg in a frying pan.

When a person passes out, call for medical help immediately. If it is heatstroke, he should be cooled immediately, but if it is a heart attack, cooling can be fatal. Carry the heatstroke victim into the shade and place him on his back with his head down and feet up so blood can circulate to his brain. Cool him by pouring on any liquids you can find or spray him with a hose. As you cool him, he will then wake up and talk to you and act like nothing has happened. While he's sitting or lying there, his temperature can rise again and he can go into convulsions or pass out again, so he must be watched for some time afterward.

Intervals to Improve Both Endurance and Speed

Cyclists, runners, and almost all other athletes have to move very fast in training to be at their best in competition. However, you can't move very fast over long distances, so athletes use a training technique called intervals in which they move very fast for a short period, move at a very slow pace until they recover their breathe, and then move very fast again and repeat these sprints a few times in a single workout. When you train intensely, you run low on oxygen to cause lactic acid to accumulate in your bloodstream. This makes your muscles more acidic to cause them to burn and you to slow down. We now know that increasing both speed and endurance for competition requires you to train so intensely that you build up lactic acid in practice sessions. This helps the mitochondria, the furnaces in muscles, to burn lactic acid more efficiently for fuel during exercise (AMAA Journal, Fall 2009). In fact, intervals markedly improve endurance for cycling competitions that take many hours and days, because the stronger you are, the less of your maximal effort is needed to get the same pressure on the pedals (Medicine & Science in Sports & Exercise, January 2005).

Duration of Intervals
Athletes in all sports use some variation of long and short intervals. Short intervals take fewer than 30 seconds and because you do not build up significant amounts of lactic acid in that time, often you can do as many as a hundred repeats in a single workout.

Long intervals usually take two to three minutes and are very damaging to your muscles. Because you feel burning in your muscles and become very short of breath for an extended period of time, you can do only a few of these in a single workout. The longer the work/rest interval, the greater the muscle damage, utilization of oxygen and sugar, and using up of muscle glycogen (Journal of Sports Science, August 2005). Athletes in all sports that require endurance usually do both long and short intervals to help them exercise intensely longer.

Short Intervals
You can do a lot more short than long interval workouts in a single workout. Intervals that last more than 30 seconds build up so much lactic acid that you get burning over a long duration that causes significant muscle damage. Short intervals between 10 and 30 seconds can markedly improve all aspects of speed and endurance (European Journal of Applied Physiology, September 2010). Since shorter intervals cause less muscle damage, beginners can start out by doing short intervals as short as six to ten seconds. Thirty-second intervals give you a better training effect and recovery during competition than six-second intervals (American Journal Physiol Regul Integr Comp, December 28, 2006).

Long Intervals
Most athletes do long intervals of two to three minutes. Intervals longer than that cause so much muscle damage that muscles take far longer to recover for the next hard workout. Many athletes do intervals lasting much longer than three minutes, but these very long intervals cause so much muscle damage that they do not do them more often than every few weeks.

Duration of Rest Between Intervals
The shorter you rest between intense intervals, the longer it takes to recover (Medicine & Science in Sports & Exercise, August 2005). Conditioned athletes doing four-minute intervals usually can recover for their next interval within two minutes (Medicine & Science in Sports & Exercise, September 2005).

Therefore most athletes slow down long enough to
• recover their breath,
• slow down their breathing, and
• relieve the burn in their muscles.

Then they do their next long interval. Most athletes start their next interval before complete recovery of heart rate and breathing rate. They should not do the next interval when muscle burning is still present. They usually terminate a workout when muscle burning or soreness persists.

Runners and cyclists often use heart rate monitors or a clock to determine when their heart rate has dropped low enough to start their next interval. Weight lifters usually wait for their bodies to "feel" recovered. Athletes learn their ideal interval rest duration during a workout through trial and error. You can use whatever yardstick for recovery from each interval you like, but if it takes you longer than two days to recover from an interval workout, you are probably exercising too intensely, doing too many repetitions, or not taking a long enough interval rest.

How Often to Do Intervals
Every time you do intense interval training, you cause a tremendous amount of damage to your muscles. Obviously it takes time to heal. If you try to do an interval workout again before your muscles have recovered, you put yourself at high risk for injuries and also impair your training because you can't train fast on damaged muscles. As a general rule, the only sport in which athletes try interval training more often than three times a week is swimming. Most athletes in most sports cannot recover faster than 48 hours from intense interval workouts. In sports such as running or cycling, competitive athletes do not improve by increasing their volume of low intensity exercise without also using intense training. Furthermore with interval training, many athletes have to decrease the volume of their slow recovery workouts done on the days after interval workouts.

Avoiding Over-training
Going out and exercising slowly over long distances will not give you much endurance unless you also exercise intensely once or twice a week at much shorter distances. A person can run a marathon or ride a bicycle century much faster by training fast two or more times a week. The most common mistake made by endurance athletes is to exercise so much that they can't maintain their speed training on their hard interval days. This is often seen in runners or cyclists who perform so many miles per week that their fast workouts end up much slower than they should be.

Scientists used to think that the primary cause of muscle fatigue during endurance exercise was running out of glycogen, the sugar that is stored in muscles. They now know that cumulative fatigue and soreness that does not go away are caused primarily by damage to the muscle fibers. The best way to protect muscle fibers is to strengthen them by exercising against increasing resistance by running, cycling, skiing or skating faster once or twice a week. However, every time that you exercise more intensely, your muscle fibers are damaged, so you have to allow time for recovery by exercising slowly the rest of the time.

How to Include Interval Workouts in Your Exercise Program
If you want to gain the endurance to walk, run, swim, cycle, skate, ski or dance for an extended time, pick two days, say Tuesday and Thursday, for speed and the rest of the time for less intense recovery workouts or days off.

On Tuesday, warm up and then start an interval workout by doing five-second intense intervals followed by a marked slowing of your breathing and complete disappearance of muscle burning. Only then should you start your next short interval. When your muscles start to stiffen or the muscle burning takes a long time to go away, you must stop your workout. Otherwise you may take weeks to recover from that workout. After many months, you will become stronger and you can try to work up to the point where you can do lots of 30 second intervals in a single workout.

On Thursdays, start out the same way as your Tuesdays but then try to work up to the point where you can do repeat bouts of sustained exercise for two minutes. Rest until you recover your breath and the muscle burning disappears, and then repeat these fast two-minute intervals three to eight times. Of course, these long intervals will be significantly slower than your short intervals.

WARNINGS: INTENSE WORKOUTS CAN KILL PEOPLE WITH BLOCKED ARTERIES. Before you start a new exercise program or increase the intensity of your program, check with your doctor.

Always stop exercising, particularly in interval workouts, as soon as you feel pain in one area that worsens with continued activity. Always stop a workout if you don't feel good. Never take an interval workout, or do any intense exercise, when your muscles are sore from a previous workout. On recovery days, exercise at reduced intensity.

Why You Need Interval Training for Both Speed and Endurance

To have great endurance for any sport, you have to do interval training: short bursts of moving almost as fast as you can, slowing down until you regain your breathe and then repeating these all-out efforts a number of times.

The old theory was that lactic acid makes the muscles more acidic which causes them to hurt and burn and interferes with their ability to contract, so you feel tired. George Brooks of the University of California/Berkeley has shown that lactic acid buildup in muscles does not make muscles tired and can make muscle contract more efficiently, which increases endurance. This research contradicts what many instructors teach in their exercise classes. When you exercise, your muscles burn sugar, protein and fat in the presence of oxygen to produce energy. If you exercise so intensely that you become very short of breath and your muscles can't get enough oxygen, lactic acid accumulates in your muscle fibers.

When you exercise, muscles need to get a lot of oxygen to turn all food sources into energy. In fact, the limiting factor to how fast you can move in sports competition is the time that it takes to move oxygen from the bloodstream in your lungs into your muscles. When you exercise so intensely that your muscles cannot get all the oxygen they need to turn sugar into energy, the series of chemical reactions slows down and lactic acid accumulates in muscles and spills over into the bloodstream.

Since lactic acid is an acid, the acidity causes muscles to burn and you have to slow down. However, as soon as you slow down enough to catch up on your oxygen debt, the lactic acid is immediately turned into more energy to power your muscles. In fact, lactic acid is a much better fuel for muscles than sugar, the second best source of energy. It is converted to energy with the lowest need for oxygen.

The major effect of regular training is to teach your muscles to use the lactic acid for energy before it accumulates in sufficient quantities to make muscles acidic to cause the painful burn and loss of strength and speed. You turn lactic acid into energy only in the mitochondria, small chambers inside muscle fibers. The more intensely you train, the greater your oxygen debt, so the larger your mitochondria become and the more mitochondria you produce in muscle cells. This helps you to turn lactic acid into energy for your muscles and requires the least amount of oxygen. Intense training is the best way to teach muscles to use lactic acid for energy. Using lactic acid efficiently for racing makes you faster and stronger and gives you greater endurance, even in competitions lasting many days.

The best way to grow new mitochondria, and to enlarge the ones that you have, is to do interval training. You move as fast as you can for a short period, become severely short of breath, slow down until you regain your breathing, and then go as fast as you can again. According to Dr. Brooks, "The intense exercise generates big lactate loads, and the body adapts by building up mitochondria to clear lactic acid quickly. If you use lactic acid up, it doesn't accumulate."

More than 20 years ago, Dr. Brooks showed that lactic acid moves out of muscle cells into the blood and enters all your organs including the liver and heart to give them an extraordinary source of energy that requires less oxygen than any other source. So the harder you exercise, the more efficiently your mitochondria turn lactic acid into energy requiring the least amount of oxygen.

In my next post I'll explain the different types of intervals and how to use them in your program, whatever your level of fitness.

Taking Sugar When You Exercise Is Good for You

My last post showed how eating refined carbohydrates and drinking sugared liquids at rest can cause high blood sugar levels, increasing risk for diabetes, heart attacks and premature death. However, during exercise, sugared drinks help you move faster and stronger. It is usually safe to take sugared drinks while you exercise because blood sugar levels rarely rise too high during exercise or for an hour afterward. Contracting muscles draw sugar so rapidly from the bloodstream that there is no sharp rise in blood sugar.

• Contracting muscles help to prevent the high rise in blood sugar that follows eating refined carbohydrates during rest (1).
• Unlike resting muscles, contracting muscles do not require insulin to move sugar inside their cells (2).
• Contracting muscles remove sugar maximally from the bloodstream, without needing insulin, during & up to one hour after exercise. The effect tapers off to zero at about 17 hours (1),(3),(4).

How fast you can run, swim, ski, skate, cycle or move your muscle in any sport depends on the time it takes to move oxygen from your lungs into your muscles. Anything that reduces your oxygen requirements will help you to move faster in sports. Your muscles burn carbohydrates, proteins and fats for energy. However, carbohydrates (specifically the sugar, glucose,) require the least oxygen to power your muscles. Anything that sends sugar rapidly into your bloodstream increases passage of sugar into muscles and helps them to burn a greater percentage of sugar so you can move your muscles faster with greater strength.

Sugared drinks provide sugar to your muscles much faster than sugared solid foods. When food enters your stomach, the pyloric sphincter closes and the stomach can squeeze only the soupy liquid into your intestines. Sugared liquids enter your intestines immediately while some sugared foods can stay up to five hours in your stomach.

Recent data show that glucose-fructose drinks are far more effective than plain water or drinks that contain just glucose in leaving the stomach faster and bringing fluid into the bloodstream faster to improve hydration during intense exercise. (Scandinavian Journal of Medicine & Science in Sports, February 2010). Therefore the best drinks to maintain endurance are those that contain glucose and fructose. Exercise drinks made with high fructose corn syrup (HFCS) may have an advantage over those sweetened with cane or beet sugar.

ALL sugared drinks should be consumed only during exercise or immediately after. When you are not contracting your muscles, quench your thirst with water or no-calorie beverages.

Why Sugar Can Shorten or Lengthen Your Life

A high rise in blood sugar can damage every cell in your body. When blood sugar levels rise too high, sugar can stick to the surface of cell membranes. Once stuck there, it can never get off. In a series of chemical reactions, glucose (the only sugar that circulates in your bloodstream) is converted to another sugar called fructose and eventually to a sugar alcohol called sorbitol that destroys the cell to cause every know side effect of diabetes: blindness, deafness, heart attacks, strokes, kidney damage and so forth.

When you eat, sugar can go into:
• your muscles, to make you a better athlete and prolong your life,
• your brain, to keep you smart and alert, or
• your liver to store sugar for future use. Sending too much sugar to your liver can make you fat, increase your risk for a heart attack and shorten your life.

At rest, your brain requires more sugar than the rest of your body combined. Ninety-eight percent of the energy to fuel your brain comes from sugar, so your brain has to have sugar available all the time. A constant supply of blood sugar to your brain helps keep you smart and alert. If your blood sugar level drops too low, you pass out, so your liver always tries to protect you from low blood sugar levels. When blood sugar starts to drop too low, your liver works to save your brain by releasing stored sugar from its cells into your bloodstream. If not enough sugar is available, the liver converts protein into sugar to keep your brain supplied.

Resting muscles are passive and can draw sugar from the bloodstream only with the help of insulin. Contracting muscles can remove sugar directly from the bloodstream without needing insulin. Contracting muscles are also extraordinarily sensitive to insulin, so it takes far less insulin to supply your muscles with sugar during exercise. These beneficial effects are maximal during exercise and for up to an hour afterward and then taper off to zero about 17 hours after you finish exercising.

When your muscles are inactive, you should avoid sugar and all refined carbohydrates. When your blood sugar rises too high, all the extra sugar goes to your liver, and that's when you damage your health. The high rise in blood sugar causes your pancreas to release huge amounts of insulin. This increases risk for a heart attack because insulin constricts arteries leading to your heart to block blood flow there. Insulin converts sugar to triglycerides and your blood fills with this fat (high triglycerides). High triglycerides increase risk for clotting, so your body tries to protect you by using the good HDL cholesterol to carry triglycerides from your bloodstream to your liver (low good HDL cholesterol). The increase in triglycerides can cause liver damage (fatty liver). Insulin also causes the extra fat to be deposited into fat cells in your belly (fat belly). Full belly fat cells block insulin receptors to make the blood sugar and insulin levels rise even higher.

People who have small buttocks are most likely to deposit fat in their bellies and are at the highest risk for diabetes and heart attacks. If you have a fat belly and small hips, you already have insulin levels that are high enough to cause severe damage to your health and are at high risk for diabetes and heart attacks. The combination of high blood insulin, triglycerides and sugar, low good HDL cholesterol and deposition of fat in the belly is called Metabolic Syndrome which means you are at high risk for diabetes and heart attacks. It happened because you eat too much sugar and refined carbohydrates when you are not exercising.

On the other hand, taking sugar when you exercise is good for you. I'll explain why in the next blog post.

Strength Training to Improve Endurance

Weight lifting can improve performance in endurance sports such as running, cycling or rowing. A study from Spain divided highly trained, competitive rowers into four groups:

1) four arm exercises leading to repetition failure,
2) four exercises not leading to failure,
3) two exercises not to failure, and
4) no resistance training.

All four groups did the same endurance training (Medicine and Science in Sports and Exercise, June 2010). Those who did the four exercises not to failure improved the most in *rowing performance, *lifting the heaviest weight that they could lift once, and *the highest muscle power output.

Athletes who train primarily for strength must train to muscle failure. That means that they lift weights repeatedly until they can barely lift that weight another time. This causes muscle damage that is necessary for maximum muscle growth and strength. The next-day muscles soreness tells them that their muscles are damaged and when thy heal, their muscles will be stronger. Then they take easier workouts until the soreness goes away and repeat their muscle-damaging workouts.

However, athletes in endurance sports must take long hard workouts lasting many hours. If lifting weights causes so much muscle damage that they cannot do their endurance workouts, they cannot compete in their sports. This study shows that athletes in endurance sports can benefit from lifting weights, but they should not go to failure so often that it reduces their workouts that are specific for their sports.

Lifestyle More Important than Genes for Longevity

How long you live is usually up to you. Extensive research show that most people who live to be 100 have never had any one else in their family also live to be 100. Longevity researcher James W. Vaupel of the Max Planck Institute in Germany feels that longevity is only three percent genetic and 97 percent environmental. Compare that to factors that govern how tall you will be, which are more than 80 percent genetic.

For most people, living to 90 or 100 requires a healthful diet, daily exercise and avoidance of exposure to life-shortening infections and toxins. Centenarians virtually never have diabetes or arteriosclerosis, the most common causes of death in North America today.

One of the best ways to compare the effects of genetics and environment on lifespan is to study twins (Twin Research, December 1998). The Danish Twin Study showed that a woman whose twin sister lives to be 100 has a four percent chance of living that long (the general population has about a one-percent chance). The Swedish Twin Registry Study followed 3,656 identical and 6,849 same-sex fraternal twins. By analyzing the age of death of twins born between 1886 and 1900, the authors found that longevity is determined a maximum of one-third by genetics and more than two-thirds by environmental factors.

Certain genes have been found to shorten or extend life, but reports on these genetic variations show that they are rare and exceptional. Paul Lichtenstein of the Karolinska Institute reported a gene called APO E4 that shortens life by carrying cholesterol into arteries to form plaques, increasing heart attacks and dementia. There is also a long-life gene called CETP-VV that prevents heart attacks and dementia. People who have CETP-VV have high blood levels of the good HDL cholesterol and large particle size cholesterol that prevent heart attacks.

However, most of the diseases that shorten life are caused primarily by environmental factors. The greatest killers in North America (heart disease, cancer, diabetes, dementia) share the same primary risk factors:
• being overweight,
• not exercising,
• not eating enough fruits and vegetables,
• eating processed meats and red meat,
• smoking,
• drinking alcohol to excess,
• storing fat primarily in your belly, and
• lack of vitamin D.

The more risk factors you have, the greater your chance of suffering debilitating disease and dying prematurely.

Emergency Resuscitation

You are in a room where a person suddenly drops to the floor unconscious. You put your ear over his heart and hear no heartbeats. That person is dead unless you pump on his chest immediately to circulate blood to bring enough oxygen to keep his brain alive, and then shock his heart with an electrical defibrillator to make it start beating again.

He passed out because •his brain suffered from lack of oxygen, •caused by lack of blood circulating to his brain, •caused by his heart fibrillating (shaking rather than pumping) or having a heart beat too weak to pump blood. His brain will die in a minute or two if you don't circulate blood by compressing his chest, and his heart will not start beating again unless you shock it as soon as possible, within about ten minutes.

Recent studies show that:

Compressing the chest first is just as successful as using the electrical defibrillator first (BMC Journal, September 2010). A study of 1,503 patients showed that survival rates were the same for immediate defribrillation and after at least 90 seconds of chest compressions before electrical defibrillation.

• Interrupting chest compressions during resuscitation reduces the chances of heartbeat return to normal after electrical shocking (defibrillation). For every second of a pause in compressions there is a one percent reduction in the likelihood of success (BMC Medicine, February 6, 2009; Circulation, October 2009).

• Mouth-to-mouth resuscitation is no better than just pressing on the chest (NEJM, July 29, 2010). You may not need to do mouth-to-mouth resuscitation in adults. However, this may not apply to children because of their small lungs.

• Place the heel of one hand between the nipples and the other hand on top of that.

• Keep elbows straight with your shoulders directly over your hands.

• With your upper body weight, push down on the chest two inches deep at 100 compressions a minute.

• Continue until signs of movement or until emergency help arrives.

Prolong Life with Exercise

How does exercise prolong life? The leading theory is that exercise prolongs life and prevents heart attacks and cancers by causing the body to dispose of free radicals with increased production of antioxidants.

Exercise speeds up the reactions that turn food into energy, so exercise actually increases the production of free radicals. The body responds to this increased production of free radicals during exercise by producing tremendous amounts of antioxidants that sop up the free radicals and render them harmless.

Most cells in your body have mitochondria, very small energy-producing chambers that number anywhere from a few to thousands in each cell. As you age, mitochondria in muscles decrease in number and size. This interferes with your body's ability to burn sugar efficiently for energy, so they produce more free radicals. Anything that increases the number and size of mitochondria helps to protect you from free radicals. Exercising helps to prevent loss of mitochondria and even makes them larger (Exercise and Sport Sciences Reviews, April, 2007).

• Mitochondria convert molecules from the sugar in food that you eat to other molecules to release energy to power most cells in your body.
• They do this by shuffling electrons from one molecule to another.
• As electrons are shuffled to produce energy, extra electrons accumulate inside mitochondria.
• Free electrons must attach immediately to something.
• They can attach to hydrogen atoms to form water and become harmless, or
• They can attach to oxygen atoms to form free radicals that can damage cells.
• Free radicals attach to your DNA genetic material in cells to damage them which causes cells to act differently than they are supposed to.
• The genetic material in cells tells the cell what to do.
• If your genetic material is functioning properly, it directs the cell to divide a certain number of times and then die, called apoptosis.
• If you genetic material in cells is damaged, the cells can become defective and go on to live forever to become cancers. • Cells with damaged genetic material also can cause heart attacks and other life-shortening conditions.

Furthermore, a team from Yale University showed that as you age, you lose your ability to make the enzyme AMP-activated protein kinase (AMPK). This enzyme functions to increase mitochondria in muscles (Cell Metabolism, February 2007). Anything that reduces the number or efficiency of mitochondria interferes with your body's ability to burn sugar for energy. As a result, blood sugar, fat and cholesterol levels rise. The extra calories that are not burned accumulate in your body as fat in your muscles, liver and fat cells. This causes you to gain weight. Extra fat in cells block their ability to take in sugar from the blood stream, so blood sugar levels rise and you are at increased risk for developing diabetes. Extra fat in the liver prevent the liver from removing extra insulin, so insulin levels rise to constrict arteries and cause heart attacks. Insulin also makes you hungry all the time to increase your chances of gaining weight.

AMPK is increased by exercise and by some of the drugs used to treat diabetes, such as metformin. The best way to increase the number and size of mitochondria in your cells is to exercise. If you do not have a regular exercise program, you are shortening your life.

Control Diabetes with Intense Exercise

"Insulin-insensitive" means that a diabetic has plenty of insulin, but lacks the ability to respond adequately to insulin that their body produces so blood sugar levels remain higher than normal. Twenty-two insulin-insensitive diabetic women participated in a supervised group endurance and resistance exercise program for six months (European Journal of Internal Medicine, October 2010). The more intensely they exercised, the better their bodies responded to insulin. Even those who did not improve their exercise capacity were able to markedly improve their body's ability to respond to insulin.

Diabetic control and cell damage is measured with a blood test called HBA1C that measures sugar stuck on cells. The more they exercised, the lower and better their HBA1C. More than 90 percent of diabetics are insulin-insensitive and have a potentially curable disease. This study shows that the harder diabetics exercise, the better their bodies respond to insulin. Insulin-insensitive diabetes can usually be cured by *losing weight, *avoiding red meat, *avoiding refined carbohydrates when not exercising, *growing larger muscles, *losing body fat, *getting blood levels of vitamin D3 above 75 nmol/L, *eating plenty of vegetables and fruits, and *EXERCISING INTENSELY. (Caution: intense exercise can cause heart attacks in people with blocked arteries. check with your doctor.)

Cycling Does Not Cause Bone Loss

During a six-day bicycle race, the bones of world class bicycle racers become stronger (Physiologie Appliquée, Nutrition et Métabolisme, June 2010). Bones are constantly changing. Certain cells called osteoblasts take calcium into bones to make them stronger, while other cells called osteoclasts take calcium out of bones to weaken them. During the race, hormones produced by osteoblasts to strengthen bones increased (osteocalcin increased by 300 percent, and C-terminal telopeptide of type I collagen increased by 43 percent).

The theory that cycling weakens bones flies in the face of our current understanding of bone metabolism. Any force on bones increases, and lack of force decreases, the rate of bone formation (Medicine & Science in Sports & Exercise, November 2009). 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.

I cannot find any studies showing that cycling weakens bones to increase fracture risk. Some studies show that 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. 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 review of 12 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.

A woman's bones are strongest when she is twenty years old. After that, she continues to lose bone for the rest of her life, and for the first few years of menopause, the rate that she loses bones more than triples. A study from the University of Erlangen in Germany shows that vigorous exercise during the menopause helps prevent osteoporosis (Archives of Internal Medicine, May 2004). In this study, fifty women lifted weights in group training sessions twice a week, and exercised by themselves twice a week. They also took calcium and vitamin D. As their muscles became stronger, so did their bones.

Sprint cyclists, and to a lesser extent distance cyclists, have greater tibia and radius bone strength than controls, with tibial bone measures being well preserved with age in all groups. This suggests that "competition-based cycling and the associated training regimen is beneficial in preserving average or above- average bone strength surrogates into old age in men" (Medicine & Science in Sports & Exercise, March 2009).

How Exercise Prolongs Life by Making You Stronger

As you age, you become progressively weaker. If you exercise regularly, you will not become as weak as other people your age who do not exercise. The same mechanism that makes you stronger will also help you to live substantially longer than people who do not exercise.

Harvard researchers have proven that exercise prevents loss of the connections between nerves and the muscles that they enervate caused by aging (Proceedings of the National Academy of Sciences, published online August 29, 2010). The researchers studied genetically engineered mice with nerve cells that glow in fluorescent colors. Muscles are made up of millions of individual muscle fibers. Every muscle fiber is innervated by a single nerve. If the nerve dies, the muscle fiber innervated by that nerve also dies. With aging, all humans and mice lose nerves that cause their corresponding muscle fibers to die also. However, mice placed on just one month of exercise in later life actually regained some of the lost connections between nerves and muscle fibers. This is the same mechanism that helps revive nerves in the brain to slow down and even stop the loss of mental function associated with aging. Exercise also prevents loss of strength associated with aging that causes falls, broken bones and injuries in older people.

Researchers at The University of Western Ontario in London just reported that competitive runners with an average age of 65 had the same number of nerves and muscle fibers as younger recreational runners, and far more muscle fibers and nerves than non-exercising age-matched controls (Medicine & Science in Sports & Exercise, September 2010).

This helps explain why exercisers live more than 12 years longer than those who do not exercise (British Journal of Sports Medicine, March 2008). Many other studies show that lifelong physically active older mammals have greater numbers of muscle fibers and their associated nerves than comparable-age mammals that do not exercise. Intense exercise is far more effective than casual exercise to:
• Prevent and treat diabetes (Circulation, July 2008; J. Applied Physiology, January 2006)
• Prevent heart attacks in obese people without weight loss (MSSE, October 2006)
• Prevent heart attacks (MSSE, July 1997)
• Reduce belly fat (MSSE, November 2008)
• Prevent premature death (Heart, May 2003)
• Prevent metabolic syndrome and heart attacks (Exercise and Sports Sciences Reviews, July 2009)
• Raise HDL cholesterol (Journal of Strength and Conditioning Research, March 2009)
(Caution: Exercise can cause heart attacks in people with blocked coronary arteries.)

Banned Drugs Probable Cause of Athlete Deaths

If vigorous exercise is good for you, why have so many former world-class athletes died of heart attacks?

The most likely cause is previous use of anabolic steroids and human growth hormone (HGH). Doctors at the Massachusetts General Hospital found that apparently healthy, older former long- term users of anabolic steroids have weaker left ventricles, the major pumping chamber of the heart. This markedly increases their risk for heart failure and heart attacks (Circulation: Heart Failure, July 2010).

Many world class athletes in sports requiring extreme strength took anabolic steroids from the early 1960s on. When these athletes were in competition, their training made their hearts stronger than those of other people their age, and available tests failed to show any heart muscle damage. With aging, the hearts of all people weaken because they lose muscle fibers. As these former users of anabolic steroids reach middle and older age, tests can detect the heart muscle weakening that increases their risk for sudden death from heart attacks.

Taking large amounts of HGH can cause sudden death from irregular heart beats. HGH causes heart muscle to grow far more than its nerves do, and everyone loses nerves with aging. The effect of former HGH use on the hearts of older athletes has not been documented, but we do know that people who have acromegaly, a brain tumor that produces large amounts of HGH, are at increased risk for sudden death from irregular heart beats.

How Sugar Makes You Faster and Stronger during Exercise

Just about everyone agrees that taking carbohydrates, particularly sugar, during exercise increases endurance in both humans and animals. For years, I have told everyone that eating sugar preserves stored muscle sugar called glycogen. However we have to find a new explanation because recent data show that taking sugar during exercise does not preserve muscle glycogen (Sports Medicine, September 2010). The NEW most likely explanation is that during prolonged, intense exercise, you become exhausted because you cannot keep up with your requirements for oxygen. This interferes with the sodium/potassium pumps, inside cell membranes, that pump potassium into cells and sodium out of cells.

Your brain sends electrical messages along nerves to tell your muscles to contract. When the electrical message that travels along nerves reaches its connection with muscles, other electrical messages travel along muscles to cause them to contract. The electricity comes from your cells' ability to keep sodium outside cells and potassium inside cells. This is done by "pumps" in the cell membranes.

During intense exercise, how fast you can move is limited by how long it takes to get oxygen into muscles. Anything that reduces your requirements for oxygen will help you to move faster. Sugar and other carbohydrates require less oxygen than fat and protein to supply energy to your "pumps", so sugar is a very efficient source of energy for the sodium/potassium pumps during exercise. When the sodium/potassium pumps lose their efficiency from lack of oxygen, potassium leaks from cells and you can't get enough electrical current to contract your muscles with the force you need to compete. So your muscles weaken and you have to slow down.

If you want to compete in sports that last more than 45 minutes, you will probably be faster and have greater endurance if you take in sugar while you exercise. Taking caffeine with sugar during prolonged exercise increases endurance even more. We drink sugared, caffeinated soft drinks when we race, and avoid them when we are not racing. When muscles contract, they remove sugar so rapidly from the bloodstream that you do not get a high rise in blood sugar. However when muscles are not contracting, you lose this benefit and can develop a high rise in blood sugar that can damage all of the cells in your body.

Heavy Weights Not Needed for Muscle Growth

Exciting research from McMaster University in Hamilton, Ontario shows that you do not have to lift very heavy weights to grow large muscles (PLoS ONE. August 10, 2010).

The heaviest weight that you can lift once is called your "One Repetition Maximum" (1RM). This study questions what many non-competitive lifters do. They find their 1RM and do three sets of five repetitions at 90 percent of their 1RM.

In the Ontario study, fifteen men were assigned four sets of leg presses with one leg. They were asked to continue to extend and contract their leg muscles until they were exhausted against 30 percent of their 1RM, and against 90 percent of their 1RM. At 90 percent of their 1RM, they were usually exhausted at five to ten lifts. At 30 percent of their 1RM, they could do about 24 lifts before they were exhausted. So the lighter the weight, the more repetitions they could do. The authors used sophisticated tests for muscle growth (mixed, myofibrillar, and sarcoplasmic protein synthesis) to show that those who lifted more times at a lighter weight have greater immediate muscle growth.

This is just another case of scientists explaining and supporting training methods after athletes have used them to be successful in competition. Richard A. Winett, a professor at Virginia Tech who has published extensively on strength training, says "the stimulus from resistance training for muscle growth comes from the effort at the end of a set, where the last repetition in good form can be performed. There's no reason to use heavy resistance; moderate resistance, good form with controlled repetitions, and a longer time under tension is effective."

Dr Winett explains that for muscle growth:
• You do not have to use very heavy weights
• You should make an effort to exhaust your muscles (lift towards failure).
• Optimal growth comes from three sets to failure for each muscle and two or three exercises per muscle group.
• You should feel mild soreness on the next day. If you are very sore, you may have used too much resistance, too much volume, too large a range of motion on an exercise, too much emphasis on the eccentric part of the repetition, or you did not get enough sleep for recovery.

Do not lift weights that are so heavy that you lose form and do only partial contractions of your muscles. Try to find a workout that is not painful when you do it, but that makes your muscles feel mildly sore on the next day. As with all exercise, check with your doctor before starting a weight lifting program.

Cholesterol in Foods OK

A review of the world's literature shows that dietary cholesterol itself is not associated with increased risk for suffering a heart attack (Current Atherosclerosis Reports, September 2010). More than 80 percent of the cholesterol in your bloodstream is made by your liver. Less than 20 percent comes from your diet. When you take in more cholesterol, your liver makes less so that your blood cholesterol remains virtually the same. The few people who do increase their blood levels of total cholesterol when they eat cholesterol-rich foods, have an increase in the good HDL cholesterol that prevents heart attacks.

Since the 1960s various organizations have recommended eating no more than 300 mg of cholesterol per day, the amount found in one egg. However, eating three eggs per day does not increase blood cholesterol levels. Poultry, eggs and shellfish, all rich sources of cholesterol, have not been shown to increase heart attack risk. Meat IS associated with increased risk for heart attacks, but I believe that the culprit is not cholesterol. A more likely explanation is the sugar-protein called Neu5GC found in meat from mammals, which may cause inflammation.

Prolong Life with Methionine Restriction?

Humans live longer when they exercise, eat lots of fruits and vegetables, keep body fat low, and restrict excess calories, meat and protein. The latest research show that restricting a certain protein building block called methionine may be more effective in prolonging life than restricting calories or proteins.

Caloric restriction with adequate intake of nutrients prolongs life in fruit flies, roundworms, and mice by increasing insulin sensitivity and heart function, and decreasing inflammation and the muscle wasting of aging. In humans, calorie restriction helps to prevent diabetes, heart disease and cancer. However, getting all of the nutrients you need while restricting calories is very difficult.

Anything that increases cell growth and increases production of new cells in your body appears to shorten lifespan. Your cells are programmed so that when food is scarce, cells lie dormant in an attempt to conserve energy to help you survive. However, when food is plentiful, extra calories stimulate new cell growth which ultimately shortens lifespan. Researchers have identified a protein in cells called TOR (Target Of Rapamycin) which promotes cell growth. Blocking TOR increases lifespan in yeast, worms, flies and mice (Aging Cell, September 2010). Caloric restriction and a drug called rapamycin block TOR to decrease cell growth and prolong life (Nature, July 8, 2009). However, rapamycin is not safe because it suppresses immunity to increase infections and it also markedly increases blood levels of triglycerides to increase risk of heart attacks.

The most potent dietary activators of TOR are amino acids, the building blocks of protein. Restricting protein lowers TOR and another major promoter of cell growth called Insulin-like Growth Factor-1 (Rejuvenation Research, October 2007). Restricting just one amino acid, methionine, extends the life of flies and mice as much as caloric restriction does (Medical Hypotheses, February 2009). Methionine is found primarily in animal products, and is very low in foods that come from plants. Eating a diet high in fruits and vegetables and low in meat and dairy products markedly restricts intake of methionine. Furthermore, this diet is much easier to follow than one that restricts calories.

Lack of Vitamin D Weakens and Injures Muscles

Because of injuries in the springtime, I missed six Boston Marathons back in the 1960s. It wasn't until 40 years later that I found the cause: my vitamin D3 blood level was 20 nmol/l (normal is greater than 75 nmol/L, equal to 30 ng/ml). Recently I moved to Florida and have been relatively injury free for the first time in my life. I now know that people genetically susceptible to vitamin D deficiency are the ones most likely to suffer muscle weakness, injuries and poor athletic performance. Many exercisers and even competitive athletes are vitamin D deficient even if they live in the sunbelt. I believe that sunlight offers benefits that cannot be obtained just by taking vitamin D pills.

Vitamin D acts directly on specific receptors in muscles to make them stronger and prevent injury (Scandinavian Journal of Medicine & Science in Sports, April 2010). As people age, they become increasingly susceptible to muscle weakness and falls caused by lack of vitamin D. Muscles are made of thousands of individual fibers that are classified into two types: slow twitch fibers that govern endurance, and fast twitch fibers that govern primarily strength and speed. Vitamin D specifically maintains the function of the fast twitch strength fibers. A review of the world's literature showed that lack of vitamin D is associated with muscle weakness in older people (Molecular Aspects of Medicine, June 2005). With aging, you lose muscle fibers. For example, the vastus medialis muscle in the front of the upper leg has 800,000 fibers in a 20 year old, but only 250,000 in a 60 year old. Vitamin D slows this loss of muscle fibers, preserves muscle strength and helps to prevent falls, while lack of vitamin D increases loss of fibers, muscle weakness and falls (Pediatric Clinics of North America, June 2010).

If you suffer muscle weakness, pain or injuries:
• Check your vitamin D3 level. That is the only available dependable test. If it is below 75 nmol/L (30 ng/ml), you are deficient.
• You can try taking vitamin D3 at a dose of at least 2000 IU/day for a month.
• If that does not bring your D3 level to normal, you can check with your doctor about taking higher doses.
• A certain percentage of people will have their vitamin D3 levels go above a normal 75 nmol/L and still suffer from muscle weakness, fatigue, pain and injuries.
• These people may benefit from exposure to sunlight.
• Since skin cancer is caused by cumulative exposure to sunlight over a lifetime, you should restrict exposure to sunlight on your head, face, top of ears, arms and hands.
• Try exposing your legs and bathing trunk areas. Be careful to avoid sunburn.
• Start at low exposures of less than a couple of minutes and work up gradually. You cannot tell that you have suffered a sunburn until the next day when your skin will burn, itch and perhaps blister.

Cold Drinks Improve Sports Performance

Drinking cold fluids lowers body temperature. More than 70 percent of the calories that you use to convert food to energy are lost as heat. So the more intensely you exercise, the more heat you produce. A rise in body temperature slows you down because the heart has to work harder to pump extra blood from your hot muscles to your skin to dissipate the heat. Seven studies show that cold beverages lower body temperature and improve performance by an average of 10 percent (International Journal of Sport Nutrition and Exercise Metabolism, April 2010).
How much water do you need?

Most Heart Attacks are Preventable

It is now established that arteriosclerosis is reversible and that most cases of heart attacks are preventable (Journal of Cardiovascular Drugs and Therapy, published online June 15, 2010). Most heart attacks occur in people with known risk factors:

Plaques caused by cholesterol:
Fatty plaques are covered by a fibrous cap that shields the fat inside from the bloodstream. Rupture of this cap releases fats from plaques into the bloodstream. The released fat causes clots that block the arteries to cause a heart attack. Heart attacks are not caused by plaques causing progressive narrowing of these arteries. Since the bad LDL cholesterol causes plaques to form, and the good HDL cholesterol prevents plaques from forming and rupturing, people with high LDLs or low HDLs are at high risk for heart attacks.

Most people could control cholesterol with diet. If this diet does not lower your LDL cholesterol below 100 or raise your HDL cholesterol above 40, your doctor may prescribe medications.

Your immunity is supposed to be good for you. When bacteria or viruses enter your body, you make proteins and cells to kill them. As soon as the germ is gone, your immunity is supposed to stop making large amounts of these antibodies and cells. However, if your immunity stays active, these white blood cells continue to produce cytokines that are supposed to dissolve the membranes of bacteria. Instead, they dissolve the caps of plaques to release fat from plaques into your bloodstream to cause clots that block arteries to cause heart attacks. Your doctor can diagnose an overactive immunity with blood tests called CRP (above 1) or Sed Rate (above 15).

Any chronic infection can turn on your immunity to increase risk for a heart attack. Check with your doctor if you have symptoms of any infection, such as bladder problems (burning on urination, frequency, night-time urination, urgency when your bladder is full), stomach problems (belching, burping, burning in your abdomen), a chronic sore throat, chronic cough, or chronic joint or muscle pains.

Metabolic syndrome (pre-diabetes) or diabetes:
People with high rises in blood sugar are at high risk for heart attacks and strokes, even if they are not diagnosed with diabetes. A high rise in blood sugar can cause plaques to rupture. You can tell if you have high rises in blood sugar if you store fat in your belly, have small buttocks, a HDL cholesterol below 40, an LDL cholesterol above 100, or triglycerides above 150. When your blood sugar rises too high, your pancreas releases large amounts of insulin (=high insulin) which causes fat to be deposited in your belly (=large belly). Insulin converts sugar to triglycerides (=high triglycerides). Then you use up your good HDL cholesterol to carry triglycerides from your bloodstream into your liver (=low HDL).

If you have metabolic syndrome or diabetes:
1) Check your vitamin D3 level. If it is below 75 nmol/L, you need more sunlight or vitamin D pills. Lack of vitamin D blocks insulin receptors to raise blood sugar levels.
2) Avoid refined carbohydrates. Altered carbohydrates cause higher rises in blood sugar. The worst offenders are flour and sugared beverages.
3) Restrict meat from mammals. The saturated fats in meat may block insulin receptors.
4) Eat plenty of vegetables and fruits. They do not cause high rises in blood sugar.
5) Lift weights. Larger muscles draw more sugar from the bloodstream.
6) Lose excess fat. Full fat cells produce hormones that prevent your cells from responding to insulin.
7) Exercise. Contracting muscles remove sugar from your bloodstream without needing insulin.

Other risk factors to avoid:
• Do not smoke or live with a smoker.
• Do not take more than two alcoholic drinks a day (a drink is a 5-ounce glass of wine, 12 ounces of beer, or 2/3rds of a shot glass of alcohol).

Sitting is Hazardous to your Health

Researchers at the University of South Carolina found that men who spent more than 23 hours a week watching TV and sitting in their cars had a 64 percent greater chance of dying from heart attacks than those who sat for fewer than 12 hours a week (Medicine and Science in Sports and Exercise, May 2010).

Many of the men who suffered heart attacks also exercised regularly. Their exercise programs did not protect them from the heart attack-causing effects of sitting in cars or while they watched television. This month, a review of the world's literature shows that exercise may not protect you from the life- shortening effects of prolonged sitting (Exercise and Sports Sciences Reviews, July 2010), and many studies show that animals (rats and mice) that do not have exercise wheels in their cages develop insulin resistance, have higher blood fat levels, are fatter, and die earlier than those who have the exercise wheels.

Now we have to explain:

1) Why sitting causes premature death and heart attacks:
• Resting muscles require insulin and respond poorly to insulin in drawing sugar from the bloodstream.
• North Americans eat a lot of refined carbohydrates that cause a high rise in blood sugar.
• A high rise in blood sugar causes sugar to stick to cell membranes, which kills these cells to cause heart attacks, strokes, premature death and nerve damage.

2) How exercise prevents premature death and heart attacks:
• Contracting muscles prevent a high rise in blood sugar by pulling sugar from the bloodstream without needing insulin.

3) Why exercise does not protect many people who spend a lot of time sitting in one place:
• Contracting muscles draw sugar maximally from the bloodstream during exercise and for up to an hour after you finish and tapers until you lose all of its benefit at about 17 hours (Am J Clin Nutr, 2008 July; 88(1): 51-57; Am J Physiol Regul Integr Comp Physiol 1983;245(5):R684-R688; Journal of Applied Physiology, February 2010).
• While you sit, your resting muscles do not draw sugar effectively from the bloodstream and 17 hours after you finish exercising, you have lost this benefit of exercise.

4) Why intense exercise is more effective than more casual exercise in:
• Preventing and treating diabetes (Circulation, July 2008).
• Preventing heart attacks in obese people without weight loss (MSSE, Oct, 2006).
• Preventing heart attacks than exercising more frequently (MSSE, July, 1997).
• Reducing belly fat (MSSE, November 2008) (storing fat in your belly is a sign of inability to respond to insulin).
• Preventing premature death (Heart, May 2003).
• Preventing metabolic syndrome and heart attacks (Exercise and Sports Sciences Reviews, July 2009).
• Raising HDL (good) cholesterol (Journal of Strength and Conditioning Research, March 2009).

Further data to show that intense exercise is superior to casual exercise:
• The faster aged runners run, the lower their blood pressure, cholesterol, and blood sugar levels (MSSE, October 2008, Arch Int Med, 1999;159(8):882).
• High intensity interval training maximally improves every conceivable measure of heart function and heart strength. (Exercise and Sports Sciences Reviews, July 2009).

Caution: Intense exercise can cause heart attacks in people who already have blocked arteries.

Why Back Surgery Fails So Often

Researchers from Duke University show that back pain is usually caused by a person's immunity attacking the disc in the same way that it attacks invading germs, not by a broken disc pressing on a nerve (Arthritis & Rheumatism, July 2010). They found that people with back pain associated with damaged discs have high levels of Interleukin-17, produced by your immune lymphocytes and known to cause asthma, rheumatoid arthritis and other autoimmune diseases.

The natural history of back pain from "disc disease" usually starts after you hurt your back. You often appear to recover after several weeks or months of pain. However, the back pain can recur any time later, even many years after your original back problem.

The bones of your spine are separated by pads called discs . When you hurt your back, you can crack the outer layers of a disc, so the softer inner layers protrude through the cracks into the spinal canal. The softer inner layers of a disc normally are not exposed to the immune system. So the human immune system does not recognize it as self and attacks it in the same way that it attacks invading bacteria and viruses. The protruding inner portions of the disc then swell to press against nearby nerves to cause pain. This research implies that the immune reaction that attacks the protruding broken inner portion of the disc causes the disc to swell and press on nerves. The authors feel that the pain is not caused primarily by broken pieces of a disc pressing on nerves so it is incorrect to use the common term "slipped disc".

If this is true, future treatment for disc disease would be to inhibit the lymphocytes that make interleukin-17. This would allow the treatment to reduce pain without blocking the body's ability to prevent infections and tumors. Either way, surgery for "disc disease of the back" has among the highest failure rates of any surgery today.

Sodas with HFCS and Caffeine May Be Best Drinks for Endurance

The limiting factor in endurance racing is the time that it takes to get enough oxygen into muscles to burn food for energy. Anything that reduces oxygen requirements allows you to race faster. Sugar stored in muscles, called glycogen, requires less oxygen than fat or protein. Anything that helps you keep sugar in muscles longer gives you greater endurance.

A study from Georgia State University shows that drinks that contain both glucose and fructose burn more carbohydrates than those containing only glucose, and allow cyclists to ride much faster over 60 miles (International Journal of Sport Nutrition and Exercise Metabolism, April 2010).

Most soft drinks are sweetened with high fructose corn syrup (HFCS). Both HFCS and conventional sugar (sucrose) contain a mixture of two sugars, glucose and fructose, in nearly the same concentrations: HFCS has 55 percent fructose/42 percent glucose, while sucrose is a 50/50 mixture. So the relative concentrations of glucose and fructose are not significant. However, the fructose in sucrose from cane or beet sugar is bound to glucose and must first be separated from it, so it is absorbed more slowly into the bloodstream. The manufacturing process for HFCS frees the fructose from glucose to makes it into a free, unbound form that is absorbed more rapidly into the bloodstream. This could cause a higher rise in blood sugar (Pharmacology, Biochemistry and Behavior, March 18, 2010) and provide more sugar for muscles during exercise. We need to wait for more research to know if HFCS drinks improve endurance more those made with cane or beet sugar.

Caffeine increases endurance (Medicine & Science in Sports & Exercise, July 2010) by increasing absorption of sugar by muscles (Journal of Applied Physiology, June 2006). Those who took sugared drinks with caffeine were able to absorb and use 26 percent more of the ingested sugar than those who took the same drinks without caffeine.

On long rides, we drink colas for their sugar and caffeine. However, you should take sugared drinks only when you exercise and for up to an hour after you finish. Contracting muscles remove sugar from the bloodstream rapidly without needing much insulin. Taking sugared drinks when you are not exercising causes higher rises in blood sugar that increase risk for diabetes and cell damage.
More on High Fructose Corn Syrup

18,000 Calories per Day in Race Across America

You need to take in large amounts of food when you exercise for more than a few hours, otherwise you will slow down and eventually have to stop. In the Race Across America, four cyclists alternated shifts as a relay team and completed the race distance of 2800 miles in 6 days, 10 hours and 51 minutes. Each rode up to 10 hours per day in approximately one hour shifts. Even though they cycled only a quarter of the time and distance, they each burned an average 6,420 calories per day, compared to the average for North American men of a little over 2000 calories per day. They ate and drank as much as they could but were able to take in only 4918 calories/day, for a deficit of 1503 calories per day (International Journal of Sports Medicine, July 2010).

Six years ago, a 33 year old bicycle racer used a continuous heart rate monitor to show that he used up more than 18,000 calories per day in the same race. He rode for 20 to 24 hours/day, sleeping no more than 4 hours/day. Yet he could eat only about half that much (9000 calories per day), and he lost 11 pounds of body fat in the nine days of competition (International Journal of Sports Medicine, July-August 2005).

More than 75 percent of North American adults weigh more than they should because they exercise too little and eat too much. These studies show that during long-term continuous intense exercise it is impossible to meet your needs for food, no matter how much you try to eat.

Caffeine to Improve Performance in Sports

Caffeine preserves muscle sugar. The limiting factor in racing in any sport is the time that it takes to get enough oxygen into your muscles to burn food for energy, so anything that requires less oxygen allows you to race faster. Sugar stored in muscles, called glycogen, requires less oxygen than fat or protein. Anything that helps you keep sugar in muscles longer gives you greater endurance.

Since caffeine is abundant in our food supply (coffee, tea, colas, chocolate and so forth), most people consider it to be very safe. However, Italian researchers report two bicyclists who took massive overdoses of caffeine and developed severe low blood levels of potassium that can cause irregular heart beats and sudden death (Clinical Journal of Sport Medicine, March 2010).

Very small amounts of caffeine help to preserve muscle sugar and increase endurance. You can increase endurance with as little as a third of a cup of most caffeinated soft drinks. No data exists to show that taking large amounts increases benefit. Up to five cups of coffee a day should not damage healthy people. A cup of coffee contains about 100 mg of caffeine, equal to two cups of tea, three cups of Coca Cola or five ounces of dark chocolate.

Caffeine is a diuretic, but not during exercise. It raises blood pressure only temporarily so this should be of concern only to people with high blood pressure. It can cause irregular heart beats, but is not likely to do so in people with healthy hearts. Caffeine appears to lower risk for diabetes.

Brown Rice Reduces Diabetes Risk

Researchers at Harvard Medical School report that replacing 50 grams of white rice daily with the same amount of brown rice lowers the risk of type 2 diabetes by 16 percent, and replacing the same amount of white rice with whole barley or wheat lowers diabetes risk by 36 percent (Archives of Internal Medicine, published online June 14, 2010). Those who ate five or more servings of white rice per week were 17 percent more likely to become diabetic than those who ate less than one serving per month. Those who ate two or more servings of brown rice per week were 11 percent less likely to develop type 2 diabetes than those eating less than one serving of brown rice per month.

White rice causes a much higher rise in blood sugar than brown rice does. The higher the rise in blood sugar, the more insulin is released by the pancreas. Excessive insulin production can eventually stop the pancreas from making insulin which increases risk for diabetes. A high rise in blood sugar also causes sugar to stick to the surface membranes of cells. Once stuck on a cell, sugar cannot get off and is eventually converted by a series of chemical reactions to sorbitol that destroys the cell to cause all the side effects of diabetes: heart attacks, strokes, blindness, deafness, kidney damage and so forth.

White rice is "refined" by removing the bran and germ portions of brown rice, which removes fiber, vitamins, magnesium and other minerals, lignans, phytoestrogens, and phytic acid. All of these nutrients may help to prevent diabetes.

All whole grains are seeds of grasses which have a thick outer capsule that requires extensive cooking to make them palatable. Removing the outer coating or grinding whole grains into flour makes the sugars readily available for rapid absorption and higher rises in blood sugar levels. More on whole grains

Skin Cancers Linked to Human Papilloma Wart Virus (HPV)

Recent research shows that both squamous cell skin cancers and actinic keratoses (pre-cancers) are caused by a combination of ultra-violet light exposure and infection with HPV, the Human Papilloma wart virus (Expert Review of Dermatology, April 2010). Some types of HPV are already known to cause cervical, head and neck cancers.

Most, if not all, actinic keratosis cells are infected with HPV (New England Journal of Medicine, May 15, 2003). Dr. Eggert Stockfleth, of the Charité Hospital in Berlin, found specific types of HPV (21, 5, 8, 16 and 18) that convert normal skin to the pre-cancerous actinic keratoses, which may then progress to become squamous cell carcinomas (Disease Markers, April 2007). To block this process before it begins, Dr. Stockfleth and his team are now developing an HPV-specific vaccine designed for the prevention of these skin cancers.

Chronic exposure to ultraviolet light damages DNA in skin cells. Your immunity tries to repair this damage, but the Human Papilloma wart viruses can prevent your immunity from repairing the DNA. Most of the time when your DNA is damaged, the cells die because they have a programmable cell death called apoptosis. However, the HPV virus prevents DNA from healing and also prevents the programmable cell death that would have removed the damaged cells (Cancer Detection and Prevention, June 2001). Then you develop scaly areas and bumps on your skin called actinic keratoses. With further exposure to sunlight, HPV causes these damaged cells that do not die to develop into squamous cell skin cancers that can spread through your body.

I think that the most effective treatment for actinic keratoses is to use a generic version of imiquimod cream (brand name Aldara) that can cost less than $200 for 36 doses. It enhances your immunity so it can better kill the Human Papilloma wart Virus (HPV). It is applied twice a week for 16 weeks, left on the skin for about eight hours and then washed off. Current treatment by most dermatologists is to destroy the lesions with liquid nitrogen or electrocautery. Surgery is rarely needed for actinic keratoses. However, once an actinic keratosis becomes a squamous cell carcinoma, surgeons usually remove the entire cancer. A pathologist usually checks the removed tissue to see that there is a 360-degree margin of non-cancerous skin around the removed cancer.

Protein After, Not During, Exercise

High-protein meals eaten immediately after hard exercise have been shown to help athletes recover faster, but the data that taking protein during exercise improves an athlete's performance is extremely weak.

Researchers from the University of Birmingham, UK, showed that adding protein (19g/hour) to a sugared drink does not improve one-hour cycling time trial, maximum power; or post exercise isometric strength, muscle damage (CPK) or muscle soreness (Medicine & Science in Sports & Exercise, June 2010). Protein also does not help athletes cycle faster in a 50-mile time trial (Medicine & Science in Sports & Exercise, August 2006). Most studies showing that adding protein to a carbohydrate drink improves performance were in people working at a fixed rate of effort over a long time, rather than using spurts of energy as athletes do in competition.

Just about everyone agrees that taking in a carbohydrate drink helps improve performances in athletic events lasting more than an hour. In events lasting more than three hours, you also need salt. Calories come from carbohydrates, fats, and proteins. During highly-intense exercise, your muscles use carbohydrates far more efficiently than proteins or fats. So carbohydrates are the calorie source of choice during intense exercise.

All sugared drinks except those with added artificial sweeteners contain eight percent sugar because that is the concentration at which the drinks taste best. You can increase endurance equally with fruit juice, special energy drinks or sugared carbonated soft drinks. Adding caffeine to the drink increases endurance even more because it helps to preserve your stored muscle sugar.

Training on Depleted Glycogen Stores?

An article from Australia shows that novice exercisers who train after skipping breakfast have higher muscle levels of glycogen (stored sugar) than those who train after eating breakfast (Journal of Science and Medicine in Sport, May 2010). When you run out of stored muscle sugar, you have to slow down, so having more sugar stored in a muscle should help you exercise longer. The faster you exercise, the greater the percentage of sugar that you use for energy. However, starting workouts with depleted stores of glycogen will not benefit competitive athletes who train for many hours each day, because restricting carbohydrates will cause them to tire earlier and thus do less work.

In another study, researchers asked competitive athletes to train either on a high or low-carbohydrate diet (Journal of Applied Physiology, November 2008). Those training on the low carbohydrate diet had much greater gains in stored muscle sugar and ability to use fat for energy during cycling, although they couldn't train as intensely as the high-carbohydrate group in the first few weeks. However, during the last week there were no differences in training. Both groups improved their one-hour time-trial performances by about 12 percent.

More recent data show that taking sugar during training sessions increases the amount of training an athlete can do without interfering with racing times (Journal of Applied Physiology, February 2009). At this time we do not have enough data to recommend restricting carbohydrates during training, or that it will increase endurance during competition.

CAVEAT! Eating foods or drinks that cause a high rise in blood sugar within an hour before a race will cause you to tire earlier. A high rise in blood sugar causes your pancreas to release huge amounts of insulin which causes you to use up your stored muscle sugar at a much faster rate. When you run out of stored muscle sugar, you have to slow down because it forces you to burn more fat which requires more oxygen. Getting oxygen into muscles is the limiting factor in how fast you can race. Researchers at the University of Hull in the United Kingdom showed that bicycle racers rode much faster 40 kilometer time trials 45 minutes after eating a low glycemic index (GI) pre-race meal than a high glycemic one (Journal of Science and Medicine in Sport/Sports Medicine Australia, January 2010). The low GI meal led to an increase in the availability of carbohydrates and a greater carbohydrate oxidation throughout the time trial. More references

Nuts Prevent Heart Attacks

A review of 25 studies shows that eating nuts (including peanuts) lowers cholesterol to help prevent heart attacks (Archives of Internal Medicine, May 10, 2010). Eating an average of 2.5 ounces of nuts per day lowers total cholesterol 5.1 percent, LDL (the bad cholesterol) 7.4 percent, and triglycerides 10.2 percent. It even lowers Lp(a), a genetic component of cholesterol that increases risk for strokes and heart attacks in young people. The more nuts a person eats, the lower the cholesterol. Those with the highest bad LDL cholesterol had the greatest lowering when they ate nuts.

An earlier review of five large epidemiologic studies and 11 clinical studies showed that eating nuts reduces risk for heart attacks (Nutrition Reviews, May 8, 2001). The most improvement came from eating two ounces (four tablespoons) of nuts five or more times a week. Eating an ounce of nuts more than five times a week can result in a 25 to 39 percent reduction in heart attack risk.

Nuts are a rich source of monounsaturated fatty acids. Before the bad LDL cholesterol can form plaques in arteries, it must be converted to oxidized LDL. LDL formed from monounsaturated fat is highly resistant to oxidation, so the LDL is less likely to be converted to its form that damages arteries. The nuts in these studies included almonds, brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pistachios, walnuts, and peanuts. Among Americans, peanuts account for approximately half of all nuts consumed.

Strenuous Exercise Prolongs the Lives of Cells

Italian researchers showed that after running a marathon, a person's lymphocytes live longer (BMC Physiology, May 2010). This could help to explain why exercisers live more than 12 years longer than those who do not exercise (British Journal of Sports Medicine, March 2008).

Every cell in your body has a programmable cell death called apoptosis. For example, skin cells live 28 days and then die. Cells lining the inside of your mouth and intestines live 48 hours, and your red blood cells live 120 days. When cells become cancerous, they live forever. They lose apoptosis and forget to die. Cancer cells then transfer to other tissues to prevent them from functioning. For example, breast cancer cells become so abundant that they may travel to your liver and damage it so you lose liver function. They travel to your brain and you lose brain function. Cancer cells kill by preventing other tissues from functioning in your body.

What would happen if your cells lived longer than they are supposed to, but still retained apoptosis and died, only later than they normally do? Perhaps you would live longer. This study shows that running a marathon prolongs the life of cells by increasing many of the messenger chemicals associated with delayed apoptosis, including SIRT1 (an enzyme that contributes to longevity).

Shortened telomeres (chromosome caps) represent aging. An earlier study showed that fifty-year-old competitive marathon runners have telomeres that were almost the same length as those of 20-year-old runners on the German National Team, and more than 40 percent longer than those or inactive men of the same age (Circulation, December 2009; reported in the February 10 eZine)

Bicycle Riding Posture

Recreational bicycle riders probably should not try to tuck their heads down in the form of racers. A study from Trinity College in Dublin, Ireland shows that "aerodynamic position" (with the head down near the handlebars) causes bicycle riders to tire earlier when they ride fast (European Journal of Applied Physiology, March 2010 and January 2006). Researchers compared how quickly cyclists tired during high-intensity cycling at constant speed in upright and supine postures. During the fatigue tests, riders performed a 10-second all-out effort followed by riding at a fast speed for 50 seconds. They repeated the all-out, 10-second bursts every minute until they couldn't go fast any more. Riding supine caused a drop in power and fatigue earlier than riding upright.

Riding bent over can reduce lung capacity in cyclists who have not trained in an aero position and adapted to it. The limiting factor in how fast a person can ride is the time it takes to move oxygen from the air you breathe into your muscles. If your lung volume is diminished, you take in less oxygen and tire earlier.

Then why do virtually all bicycle racers try to ride lower and lower? Because air resistance slows you down and the lower and narrower you ride, the less air pushes against your body. When you pedal on level ground with no wind blowing, 60 percent of your energy is directed to overcome air resistance against your body. Ed Pavelka, a world-class endurance bicycle racer, says: "The fastest speeds in cycling are obtained on aero bikes with the handlebar well below the height of the saddle. Fatigue is caused by the duration and intensity of effort, and reducing the work you have to do against air resistance is more important than anything else."

If you are not a bicycle racer, you will probably be more comfortable and ride longer if you don't try to get as low as possible. To receive Ed Pavelka's free weekly newsletter, with great information for racers and recreational riders, go to

Muscles: Incredible Health Benefits

Almost all people should do some form of strength training as they age. Aging causes loss of muscles which increases your risk for metabolic syndrome, diabetes, obesity, heart attacks and premature death (Sports Medicine, May 2010). Contracting muscles remove sugar from the bloodstream to prevent high blood sugar levels which damage every cell in your body.

The authors reviewed the world's literature and found 13 placebo-controlled studies of the effect of lifting weights on health in later life. Weight lifting reduced HbA1c (a measure of cell damage caused by sugar stuck on cells), body fat, and systolic blood pressure. It did not affect diastolic blood pressure, triglycerides, HDL, LDL or total cholesterol.

The only way you can enlarge muscles is to exercise them against progressive resistance. However, a recent report explains why middle-aged people are at such high risk for injury when they start a weightlifting program (American Journal of Lifestyle Medicine, May 2010). To enlarge muscles, you have to lift weights heavy enough to cause pain while you lift. This damages muscle fibers. Your immunity responds to this cell damage as it responds to an infection: with pain, swelling, and increases in white blood cells, cytokines and blood flow. You usually recover within hours or days. However, if you repeat a heavy workout before you recover from the previous one, it takes longer to recover and the tissue weakens, rather than being given time to heal and become stronger. You develop a condition called inflammation in which your immunity stays active all the time and attacks your own body (in the same way that it attacks invading germs) to prevent healing. Older people have exaggerated changes of inflammation in their muscles (American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, April 2010). If you continue to take stress and recover workouts over many months and years, your muscles become stronger and heal faster so you can lift heavier weights to grow larger muscles.

If you are a middle-aged person who wants to start a weight lifting program to gain the incredible health benefits of being stronger and having larger muscles, and at the same time, avoid the extremely high rate of injury in older weight lifters, you should avoid lifting heavy weights when your muscles feel sore and are still damaged from your previous intense workout. Check with your doctor to see if you have any condition that could be aggravated by lifting weights.

The first rule is that beginners should lift light for several months before they try to lift heavy. Join a gym and use 10 to 20 machines every day. Pick the heaviest weight that you can lift 10 times in a row comfortably without hurting, and do this every day. If you feel sore, take a day or more off. As it becomes easier to lift a weight, increase the repetitions until you can lift that weight 25 times in a row without discomfort.

After you have followed this program for several months, you are probably ready to lift heavier weights that cause pain while you lift them. Unfortunately, the correct way to grow muscles also puts you at increased risk for injuring yourself. Pain is necessary for the muscle damage to grow larger and stronger muscles. I recommend getting special instruction on how to perform multiple sets that hurt, using proper form to minimize the risk of injury. Many lifters pick the heaviest weight that they can lift 10 times in a row, do three sets of 10 and feel very sore in their last set. After an intense workout, you should not lift heavy again until the soreness goes away. More