When people contemplate aging, the ability to live and function independently is a primary goal. There are many threats to this ambition, including loss of physical strength and coordination, erosion of thinking and reasoning skills, and the toll of chronic illness. Genetic background also plays a large role in the quality of a person's old age.

Geriatric disability presents a challenge to individuals, as well as to society as whole, particularly since it has been projected that by 2030, 1 out of 5 Americans will be 65 years or older. Although there are numerous medications that attempt to address various age−related problems, they typically fall far short of restoring an individual to completely normal function. Every day an older person can read about some anti−aging remedy or another. Most are not definitively proven by research.

[The most vigorous walkers] had a 50% higher chance of successful survival than their more leisurely walking peers regardless of their weight and even if they didn't do any other exercise.

The Answer is Exercise
However, there is one way to improve your old age. The profound benefit of regular exercise is receiving enthusiastic attention from the medical community and holding up to close scientific scrutiny.

But what kind of exercise — stretching, strength training, toning, aerobic? How much exercise is needed and how often must it be done? Can most adults achieve the goal of exercising enough to make a difference without getting injured or causing other health problems? What if they've never exercised before? Several studies recently published in the January 25 edition of the Archives of Internal Medicine take on these issues and begin to sort out this complex area.

Walking Works
One study addressed the relationship between exercise and healthful aging. The researchers followed 121,700 women who had no chronic illnesses and were ages 30−55 years old in 1976. They administered questionnaires every two years that included physical and mental health, demographic, and lifestyle information. In 1986 they added detailed questions about physical activity and exercise habits and translated different activities into a standardized measure, metabolic equivalent tasks (METS.) Using this standard measure allowed them to compare the amount of exercise obtained from a variety of activities based on how many METS each form of activity produced. For example, running generates 12 METS per hour while bicycling generates 7 METS. Thus it takes almost two hours of bike riding to equal an hour of running.

Walking was found to be a surprisingly effective form of exercise. Among participants whose major exercise was walking, there was a clear advantage to those whose walking generated more METS, in other words, those who walked most vigorously. Researchers found that the people in the two groups which were ranked first and second highest in the amount of energy used in walking all had a 50% higher chance of successful survival than their more leisurely walking peers regardless of their weight and even if they didn't do any other exercise.

The investigators concluded that both lean and overweight women who engaged in midlife leisure time physical activity were more likely to be healthy in old age and that walking at a moderate to brisk pace was a form of exercise that could make a difference. This finding places an exercise−based intervention easily within the grasp of most Americans.

"Successful Survivors"
Between 1995 and 2000, the researchers on this study invited all participants who were 70 years or older to participate in an evaluation of their physical and mental states.

Their goal was to see how exercise was related to successful aging. They defined a successful survivor as someone who reached at least age 70 with:
  • No history of several chronic illnesses (cancer, diabetes, heart attack or bypass, congestive heart failure, stroke, kidney failure, pulmonary disease, Parkinson's disease, multiple sclerosis or amyotrophic lateral sclerosis)
  • No impairment of thinking function
  • No physical disabilities,
  • No mental health limitations.

Ten percent of their original study group were successful survivors. Women who engaged in rigorous physical activities such as playing tennis, jogging, running and doing aerobics were more likely to be successful survivors than those who didn't. Increasing the amount of exercise made an increasing difference in successful aging. Those people who had exercise routines with the most METS were twice as likely as the lowest group to be successful survivors.

Exercise for Bones, Heart and Balance
Another group of researchers questioned whether a single exercise program would decrease fracture risk, number of falls, and incidence of coronary heart disease. They realized that there were different types of exercises prescribed for different situations. For example, balance and endurance practice might improve risk of falls, weight−bearing exercise is prescribed to improve bone mineral density, and aerobic exercise is aimed at cardiac improvement. They felt that most seniors would not want to do multiple exercise programs and so they tried to design one that would encompass all goals and be appealing to most senior citizens. Additionally, they wanted their exercise program to be effective without increasing health care costs by leading to injuries or other health problems. They recruited 246 women who were 65 years or older and were living independently. The study group participated in an 18−month exercise program and the control group participated only in a wellness program with low intensity and low frequency exercise.

[E]xercisers were roughly half as likely to fall as those not in the exercise program and if they did fall, they less likely to be injured. There were twice as many fractures among the non−exercise as among the exercise group.

The test group's program was a low volume, high impact and high intensity strategy requiring two one− hour exercise classes and two 20 −minute at home sessions per week. It included aerobics, static and dynamic balance, strength training and stretching and addressed both the upper and lower body muscle groups.

Exercise had a positive effect on the bone mineral density. After 18 months the bone mineral density of the upper leg bone, (the femoral neck) of exercisers increased slightly, while the non−exercisers showed a decreased BMD. More compelling was the fact that exercisers were roughly half as likely to fall as those not in the exercise program and if they did fall, they less likely to be injured. There were twice as many fractures among the non−exercise as among the exercise group.

Both the test and the control groups had improved blood pressure. The test group also had improved blood lipid measurements, which decreased their risk of coronary heart disease. There were no musculoskeletal injuries, cardiac events or other adverse affects in the high exercise group. The researchers concluded that it was possible to design a safe, acceptable, multipurpose exercise program for seniors that could improve quality of life by increasing bone mineral density, decreasing risk of falls, and improving risk factors for coronary heart disease.

Another study, reported in Archives of Neurology and discussed in a related news item on TheDoctor, addressed the way exercise can help maintain thinking and reasoning skills as people age.

Because it puts a promising intervention well within the reach of the average citizen, this research is both exciting and reassuring. Multiple studies are being done to help develop appropriate recommendations. Middle−aged and senior citizens may want to find ways to include exercise safely into their daily routines. It is important to work with a physician and a trainer or exercise coach who is knowledgeable about the challenges of older "athletes" and knows how to adapt programs to meet each individual's physical abilities and preferences. One resource for guidelines for exercise can be found on the Center for Disease Control website: http://www.cdc.gov/physicalactivity/everyone/guidelines/olderadults.html