Estimates indicate that nearly 250,000 deaths per year in the US -- about 12 percent of total deaths -- are due to a lack of regular physical activity. Surveys show that only 22 percent of American adults get enough leisure-time exercise to achieve cardiovascular fitness.

Exercise benefits every part of the body, including the mind. Exercising causes the body to produce endorphins, chemicals that lead a person to feel peaceful and happy. Exercise can help some people sleep better. It can also help with mental health issues such as mild depression and self-esteem.Exercising can help you look better, too. People who exercise burn calories and look more toned than those who don't. In fact, exercise is one of the most important parts of keeping your body at a healthy weight.

The normal vital sign values change with aging.The vital signs include body temperature, pulse (heart rate) , respiratory rate (breathing), and blood pressure .Normal body temperature does not change significantly with aging.Because of changes in the heart, the resting heart rate may become slightly slower. It takes longer for the pulse to speed up when exercising, and longer to slow back down after exercise. The maximum heart rate reached with exercise is lowered.

Blood vessels become less elastic. The average blood pressure increases from 120/70 mm Hg to about 150/90 mm Hg and may remain slightly high even if treated. The blood vessels also respond more slowly to a change in body position.There may be decreased tolerance to exercise. Some elderly people have a reduced response to decreased oxygen or increased carbon dioxide levels (the rate and depth of breathing does not increase as it should).

Older people who have long been physically active, and remain so, have better balance than less vigorous seniors, while those who pick up the exercise after retirement fare almost as well, French researchers report.

However, individuals who exercised in the past, but stopped after retirement, had balance control nearly as bad as those who had never been active, Dr. Philippe Perrin of the Universite Henri Poincare-Nancy, Villers-les-Nancy, and colleagues report.

Many older people experience a decline in their balance control, reducing their independence and putting them at increased risk of falling, Perrin and his team note in the January issue of the International Journal of Sports Medicine.

Exercise interventions, such as tai chi programs, improve balance and reduce fall risk, they add. There is also evidence that people who have been active for a long time can control their balance more effectively due to stronger muscles and a better ability to gauge their position in space using sensory receptors and the inner ear's balance system.

To investigate how physical activity affects balance, Perrin and his team assigned 130 men and women, who were an average of 70 years old, into four groups based on past and current activity level. The groups included people who were physically active before and after retirement, averaging 45 years of activity; those who started to exercise after retirement, and averaged 11 years of physical activity; those who were active before they retired, for an average of 15 years, but were no longer active; and people who had never been active.

All underwent the Sensory Organization Test, in which they tried to maintain their balance under challenging conditions.

Seniors who were active and continued to be so in retirement scored highest on the test, while the totally inactive group scored the lowest. Men and women who first started to exercise in retirement had balance abilities similar to those who were always active, while those who had stopped being active had scores close to the men and women who were never active.

Active individuals had balance test scores similar to those of inactive people 10 to 15 years younger, the researchers found.

"Our data encourage people who have never practiced physical activity in their life, without cardiovascular (limitations), to take up physical activity...both to counteract the effects of aging on balance function and to reduce the risk of falls," they conclude.

Some things to keep in mind:

• Use your medicine, particularly your inhaler, before your exercise to help you exercise longer with less shortness of breath.
• If you become severely short of breath with only minimal exertion, check with your health care provider about changing your medicines. He/she may even suggest having you use supplemental oxygen before you begin your activities.
• It is important to take plenty of time to warm up and cool down before and after exercise. For those with exercise-induced asthma, a 6-10 minute warm-up period before exercising is recommended.
• Keep your level of exercise well below those levels that cause severe shortness of breath.
• Swimming can be quite helpful for those with chronic lung disease since cold and dry air can make breathing and exercising more difficult.
• Strengthening exercises such as light weightlifting and rowing may be helpful, particularly for people who have become weakened or de conditioned from medications such as steroids.