Everyone should maintain excellent physical conditioning throughout their lives. You never know when you may need to use it. When I lived in Nevada, sometimes a family would decide to spend a Sunday afternoon exploring one of the many ghost towns. Some ghost towns, although in a desert area 20 miles from a paved road, were reachable in a family car. The problem was that sometimes the car would break down and the family would be stranded in the desert. Then the father had to hike back to the paved road for help. Some did not make it. In December 1999, a radio station had a contest winner that got to run back and forth for a few minutes between a bank vault and a storage container carrying as much loose currency as he could carry each trip. He started off great but started slowing down and passed out from exhaustion after only a few trips and had to transported to a hospital. He ended up with $80,000 but could have had much, much more if he had been in good condition. Since you never know when it may be needed, you should stay in excellent physical condition at all times. As the late comedian George Burns once said "If I had know I was going to live this long, I would have taken better care of myself."

Taekwondo students train for many reasons. They train to strengthen themselves mentally and physically, to gain flexibility, and to perfect their Taekwondo techniques. They also train to replace instinctive responses, such as panic, covering, turning away, or clashing with attacks, with trained responses, such as calmness, evading, redirecting, and dispersing of attacks.

Students train to develop a constant awareness of their surroundings so they may quickly evaluate and react to problems. They train to remain a calm, dispassionate, and impartial when facing an attacker They train to develop their peripheral vision so they may defend against attacks from their periphery.

In a self-defense situation, the defender must evaluate what defense or attack is required and what amount of force is required. Intensive training is required before these evaluation may be made quickly and legally. Fear or surprise may make it difficult to execute subtle movements involving fine motor skills, so extensive training is needed to make these movements instinctive.

A 1990 study by University of Illinois researchers found that rats trained to cross rope bridges and pencil-wide beams to increase their coordination, possessed 25 percent more neuron connections to other brain cells that rats who only ran on treadmills.

A 1999 study by researches at the Salk Institute for Biological Studies found that running doubled the number of new brain cells that survived in adult rats.

A 2002 study by Stanford University had 6213 men walk on a steeply inclined treadmill until the point of exhaustion. After tracking the men for the next six years, the study found that the men who tired first on the treadmill test died at a 4 times greater rate then the men who were in the best shape. For every step up in physical fitness, the men were 12 percent more likely to live longer, even when they had other risk factors such as diabetes, smoking, hypertension or high cholesterol.

A 2002 British study of 2,341 women ages 60 to 79 found that doing housework as exercise does not seem to improve health or lower weight or resting heart rate, while brisk walks do. Work, no matter how strenuous, is not exercise. To increase health significantly, physical activity should be performed specifically as exercise, not as work.

A 2002 report from the National Academies' Institute of Medicine, recommends that people get one hour of physical activity a day. This is up from the half hour recommended in a 1996 surgeon general report. The activity may be from many sources, such as walking gardening, playing tag, Taekwondo, etc. and it may be done in increments that add up during the course of a day. The report also says the best diet for minimizing the risk of chronic disease is one that get 45% to 65% of calories from carbohydrates, 20% to 35% from fat, and 10% to 35% from protein. The daily intake for fiber should be 38 grams for men and 25 grams for women in the ages 50 and under. For men over 50, it is 30 grams, and for women over 50, it is 21 grams. The minimum daily intake of carbohydrates for adults and children should be 130 grams. No more than 25% of total calories should come from added sugars. Saturated fat (found in meat and high-fat dairy products), cholesterol, and trans fatty acids (found in cookies, cakes, and processed foods) should be kept as low as possible.

A 2002 study by Duke University of 111 sedentary, overweight men and women found that even modest exercise may benefit the heart by making cholesterol less damaging to the heart, even if the cholesterol level is unchanged. Previous research showed that exercise does not lower the dangerous LDL form or cholesterol and that only rigorous exercise can raise HDL, the good form. Cholesterol spreads through the body by attaching to protein particles. Cholesterol seems more likely to clog arteries when it is called by small dense protein particles than when it is carried by large fluffy ones. The study found that people who exercise develop these large protein particles. Good effects were found in subjects who either walked or jogged 12 miles a week while effects in those who jogged 20 miles a week were even more pronounced.

A 2002 study by the University of Ulster in Northern Ireland found that 10 minutes of exercise three times a day was just as effective as one 20 minute session. They found that the short bursts were also great for improving mood.  This is good information for people who are just starting an exercise program.

A 2003 study by Queen's University in Belfast Ireland found that only vigorous exercise helps lower the risk of early death from heart attack. This contradicts Unites States guidelines and a World Health Organization consensus report that say 30 minutes of moderate activity daily is sufficient. The study followed about 200 men, between the ages of 49 and 64 with no evidence of heart disease, for ten years. The study found that men who did the most exercise over the ten years were 40 percent less likely to die than those who did the least.

A 2003 study by the American Cancer Society tracked 900,000 adults for 16 years and found that excess body fat may contribute to about 20% of all cancer deaths in women and 14% of all cancer deaths in men. Overweight and obese women had a higher risk from most types of cancer, including cancer of esophagus, colon, liver, pancreas, and kidneys. Overweight and obese men had an increased risk of death from cancer of the stomach and prostrate. Obesity did not raise the risk of death from lung cancer, brain cancer, or melanoma.

"I don't need to work out, I work hard everyday!" In 2003 study, German researchers looked at nearly 800 people, 40 to 68 years old, about 40 percent of them with confirmed heart disease, to discern the relationship between heart disease and exercise. They found that people who work hard during the day, such as landscapers or dock workers, but are couch-potatoes at night are more likely to develop heart disease than desk jockeys who train regularly. They found that those who experienced heavy work-related physical strain had a 5 percent chance of having coronary heart disease–five times the rate of those in jobs without physical strain. Regular exercise helped lower the risk for hear disease in both groups.

Many studies suggest that when people fall into rapid-eye-movement (REM) sleep soon after learning something new, they are more likely to retain the new knowledge. And non-REM sleep may give inactive neurons a chance to repair damage caused by free radicals. So late night Taekwondo classes are good for learning new patterns.

Larry Katz, a Duke University neurobiologist says, to increase your range of mental flexibility, you should stimulate rarely activated pathways in your brain by doing such things as brushing your teeth with the wrong hand, showering with your eyes closed, sleeping on the wrong side of the bed,  or taking a new route to work.

Research has shown that waist size is a better indicator of body-fat than the popular body-mass index (that uses weight and height). Fat on the lower portions of the body, such as the buttocks, hips. and thighs, is less dangerous than fat in the abdomen. Fat on the lower body collects just under the skin. Abdominal fat collects internally around the organs. According to The National Heart, Lung, and Blood Institute, the risk for health problems increases at a waist measurement of 35 inches for women and 40 inches for men. However, a recent study by the New York Obesity Research Center at Columbia University found that the risk of heart disease and diabetes starts increasing at a waist measurement of 33 inches for women and 35 inches for men. These numbers hold true regardless of height or age. You cannot get rid of abdominal fat through spot exercises, you must decrease your overall weight. The good news is that when you exercise and lose weight, the metabolically active abdominal fat comes off faster than fat on lower parts of the body. When measuring your waist, you must measure accurately. Along the side of your body, locate your lowest rib and the top of your hipbone. Place a tape measure around your abdomen at a point halfway between these two points. Stand up straight, do not suck in your stomach, take a deep breath, exhale, and take the measurement at the end of the exhalation.

Two studies published in 2003 in The Journal of the American Medical Association show the benefits of exercise on women. One study of 74,171 post-menopausal women over five years found that those who did 75 to 180 minutes of exercise per week had a 18% less chance of developing breast cancer than inactive women. A second study of 201 obese, sedentary women who were on the same specified diet found that moderate exercise for an hour a day was more effective in losing weight than shorter more intense exercise sessions and was more effective in preventing heart disease.

In 2004, the American Council for Exercise reported that people burn 10 percent more fat calories with early morning workouts, but that endurance peaks between 3 and 7 p.m. Morning exercisers are more consistent in the fitness habits, but the risk for injury lessens later in the day since synovial fluid, which lubes our joints and lessens inflammation, works better as the day progresses.

A 2004, a study published in Medicine & Science in Sports & Exercise in the journal of the American Colleges of Sports Medicine reaffirms the value of the "talk test" in determining when you are exercising too hard. People who can converse or, as test subjects did, recite the Pledge of Allegiance, while exercising are not likely to overexert themselves. This test works for people of all levels of fitness. The bottom line is, you should be able to talk normally while exercising.

In 2006, in the Journal of the America Medical Association, researchers at Brigham and Women's Hospital in Boston reported on the measured risk for heart diseases among more than 27,000 women as a part of their continuing Women's Heath Study. They found that being either overweight or inactive each independently raised risk factors for heart disease but that women at any weight reduced their risks by exercising. They found that that even inactive women had lower risks than slightly overweight active women. They also found that thin women who exercise had lower risks that thin women who did not exercise. The study showed that, not matter your weight, exercise lowers you risk of heart disease.