An 85-year-old runs in the Los Angeles Marathon and comes first in his class. A 78-year-old sailed solo to Hawaii and at 82 issues a challenge to other mature sailors to duplicate his feat. A 57-year-old woman swims almost 30 miles around Manhattan Island. A 90-year-old regularly visits Canadian schools to promote fitness and to encourage young people to accompany him on his regular long distance walks.

Unfortunately, these active seniors hit the news because, even in our health and fitness conscious society, they are the exception rather than the norm. According to the Canadian Fitness and Lifestyle Research Institute, two-thirds of all senior Canadians have dangerously inactive lifestyles. According to the 1996-97 National Population Health Survey, only 34 percent of men and 29 percent of women over the age of 55 engaged in 15 minutes or more of physical activity each day. The same study shows that among adults over age 74, only 29 percent of men and 19 percent of women are physically active, sobering statistics for an age group whose sustained quality of life and independence hinges on physical fitness.

Walking, weight lifting and flexibility training can help seniors avoid disabilities normally associated with aging and even reverse the aging process itself, according to a University of Texas study reported by the Center for Advancement of Health. Some decline in physical ability is an inevitable result of normal aging, but inactivity can hasten this decline and result in all-too-rapid rates of muscle atrophy, decreased endurance and loss of flexibility and balance, according the study’s lead investigator, and his colleagues at the University of Texas Medical Branch in Galveston.

Strength Training

Studies have shown that strength training by people in their 60s to 80s can improve longevity and quality of life. As we age, our bones and joints weaken. Strength training not only helps support the bones and joints and lessen the impact of their weakening but also improves coordination, muscle control and mobility.

Muscle can still grow and develop in people over 90. In documented research studies, older adults have increased their strength from 10 to over 100 percent in just eight weeks. There are documented cases of individuals who required a cane or a walker to get around, but after strength training they no longer needed those items for mobility.

Research at the University of Maryland has shown that strength training is effective for improving glucose metabolism, increasing bone mineral density and speeding up gastrointestinal transit. Studies at Tufts University have demonstrated that strength exercise adds lean tissue, increases resting metabolism and reduces arthritic discomfort. And researchers at the University of Florida has shown that strength training increases low back strength and alleviates low back pain.

Strength training means working a group (or groups) of muscles against resistance so that the muscles become fatigued. The stimulus of the resistance eventually causes the muscles to contract with greater force, resulting in increased strength and perhaps increased muscle size. The resistance can be applied in a number of ways. Machines, barbells, air cylinders, water, rubber tubing, elastic bands and even body weight can be used as resistance.

Walking

Walking has been recognized as important to health and well-being as early as 400 B.C. Hippocrates wrote, “Walking is man’s best medicine”. Walking more than four hours a week reduces hospitalizations from heart disease. For many people, walking 30 minutes three days a week can lower blood pressure five to ten points. Speed doesn’t necessarily count, since people who walk three miles per hour show the same six percent rise in good cholesterol as people who walk at five miles per hour.

Since it is a weight-bearing exercise, walking has specific benefits for the muscular, skeletal, endocrine and nervous systems too. Walking more than four hours each week can reduce the risk of bone disease like osteoporosis by maintaining bone mass. If you are diabetic, walking can help you use insulin more efficiently. Walking regularly can help you keep your weight in control and reduces anxiety.

The capacity of lungs to absorb oxygen normally declines an average of one percent a year after age 40. A walking program for people in their 70s cited in the University of Texas research study reversed 22 years of declining lung capacity in 22 weeks.

Aerobics

Walking is an aerobic exercise. Aerobic means using oxygen. To achieve aerobic conditioning, you must engage in vigorous, sustained exercise at least three times each week. You must raise your pulse rate to a target range and maintain it in that range for the entire time.

Calculate your Target Heart Range by subtracting your age from 220 for women and 226 for men and multiplying your answer by 60 percent and by 80 percent. The lower number suggests a safe rate for beginners, while the higher number would be your goal as your fitness level improves.

Other aerobic activities include jogging and running, bicycling, aerobic dancing, tennis, swimming and cross-country skiing. Most aerobic activities can also be done indoors on exercise equipment at home or in a gym.

Of course, there are some health conditions that mean you should avoid certain types of strenuous activity. So consult a doctor or fitness consultant before you begin a new exercise regimen. No matter what type of fitness activity you choose as you age, be sure to build 30 to 60 minutes of moderate physical activity into your life most days of the week as a prescriptive for ongoing health and independence.

Do you get one cold after the other all winter? Afraid you'll be a flu victim this year? According to researchers, avoiding getting sick may be as easy as taking a daily walk or following a simple exercise routine a few times a week. Exercise not only helps your immune system fight off simple infections, but it may actually decrease the incidence of illnesses such as heart disease, osteoporosis and cancer.

One of the first studies to look at the effects of exercise on the immune system took place in the 1980s. Researchers then reported that 61 percent of 700 recreational runners surveyed said they had fewer colds once they began running, while only four percent felt they had experienced more.

More recent studies have found that two or three short exercise sessions throughout the day can be just as beneficial – if not more so – than one long bout. A study at Texas Christian University found that exercisers who rode a stationary bike for one hour twice a day – once in the morning and again in the afternoon – not only had significantly higher counts of important immune system cells than non-exercisers, but their immunity was even higher after the second bout of exercise.

Fortunately, you don’t have to pedal two hours a day to benefit, says lead researcher Brian McFarlin, a PhD candidate in exercise physiology at Purdue University in West Lafayette, Indiana. He told the American College of Sports Medicine’s annual meeting in 2001 that “when you can’t find a 30- or 45-minute block of time to exercise, your immunity may benefit even more by grabbing a few shorter workouts throughout the day.”

According to research published in Medicine & Science in Sports & Exercise, even elderly people who aren’t able to work out in the normal sense can strengthen their immune systems with a bit of increased physical activity. A group of Dutch scientists worked with 112 frail men and women for 17 weeks. The volunteers, whose average age was 79, all lived independently but required some outside assistance such as home care or home delivered meals.

The participants were divided into four groups. One group engaged in a moderately intensive, 45-minute exercise program twice a week; a second group consumed daily portions of food enriched with vitamins and minerals that are frequently under-represented in the diets of older adults; a third both exercised and ate enriched food; and a fourth did neither.

The researchers found that those individuals who participated in the exercise program showed a small but meaningful increase in their immune response. While the group eating enriched foods experienced a beneficial increase in their blood levels of vitamins and minerals, there was no observed change in their immune response.

Although researchers are not yet entirely sure why exercise is so good for the immune system, they do know that during moderate exercise, several positive changes occur in the immune system. Once the moderate exercise bout is over, the immune system returns to normal within a few hours.

One theory is that physical activity may help by flushing bacteria out from the lungs (thus decreasing the chance of a cold, flu or other airborne illness) and may flush out carcinogens by increasing waste output, such as urine and sweat.

Exercise increases the heart rate, which in turn speeds the circulation of antibodies and white blood cells through the body. Research shows that white blood cell counts can increase by anywhere from 50 per cent to 300 percent after exercise.

In addition, the temporary elevation of body temperature may inhibit bacterial growth, allowing the body to fight the infection more effectively.  Finally, exercise slows down the release of stress-related hormones, and stress hampers the immune system, increasing the chance of illness.

In 1989 by David Nieman, PhD., a professor of exercise science at Appalachian State University and a leading expert on exercise and immunity, reported that moderate exercise produces a steady increase in the activity of natural killer cells, one kind of white blood cells, compared to those who don’t exercise regularly.

Nieman studied 50 women in their 30s and 40s, half not exercising and half who walked for 45 minutes a day, five days a week. The walkers reported half as many days with cold or flu symptoms as their counterparts. Blood tests showed that antibody levels climbed steadily among the walkers during the 15-week experiment. Nieman also charted a steady increase in the activity of natural killer cells.

While all this is good news for those who already exercise, there can be too much of a good thing. People who already exercise regularly are cautioned not to develop too vigorous a workout program. Studies have shown that prolonged bouts of high intensity endurance exercise can make athletes susceptible to illness – especially upper respiratory tract infections – for up to 72 hours. Heavy, long-term exercise may actually decrease the amount of white blood cells circulating through the body and increase the presence of stress-related hormones.

So, while we don’t know exactly how and why exercise increases our immunity to certain illnesses, we do know that exercise helps. It decreases our chances of developing heart disease and osteoporosis and may help us avoid those nagging coughs and colds. Exercise can help us feel better about ourselves, just by making us feel more energetic and healthier. Studies have shown that the people who benefit most from starting  an exercise program are those who go from a sedentary lifestyle to a moderately energetic one. A moderate program can consist of daily 20 to 30 minute walks, going to the gym every other day, playing golf regularly or bicycling with the children a few times a week.