Update No. 1: In collaboration with the American College of Sports Medicine, the Centers for Disease Control has recommended that adults engage in physical activity totaling 30 minutes a day, no fewer than five times per week.
These activities can be "lifestyle" activities such as gardening, raking leaves or walking up stairs and they do not have to be continuous. The CDC emphasized that exercise does not have to be strenuous or time consuming to give benefits in terms of decreased risk for heart disease and cancer.This is a major change in focus for Americans in terms of the guidelines for fitness. These changes were brought about in an effort to encourage all of us to become more active and replace the old, more formal guidelines that required from 20 to 60 minutes of continuous, large muscle activity at a heart rate between 70 and 85 percent of maximum. Although the "old" guidelines were effective, and could make measurable changes in cardiovascular fitness, they probably sounded too difficult for the average, inactive American adult.
At the present time, only 22 percent of adults engage in leisure-time activity at the level suggested for health benefits under "Healthy People 2000" goals. More than 250,000 deaths annually can be attributed to physical inactivity.
Update No. 2: Speaking of the "Healthy People 2000" goals, 50 of the health goals for the year 2000 were designed specifically to improve the health of women. One of these, the prevalence of an overweight condition in women, is going the wrong direction. The preliminary data from the 1988-1991 National Health and Nutrition Survey, which is based on measured height and weight, show a 30-percent increase in the proportion of overweight women since the 1976-80 baseline. These data highlight the need for women to participate in physical activity, because physical activity is the most important predictor of success in weight management and long-term weight control.
Update No. 3: An interesting news release from the American Optometric Association supports the need for antioxidants in the diet. Although major studies are still under way, preliminary reports in the December issue of the Journal of the American Optometric Association are promising enough to recommend changing your diet or even adding a vitamin and mineral supplement to prevent age-related macular degeneration.
Macular degeneration is the result of the destruction of light-sensitive cells in the retina, which lines the back of the eye. The result is a loss of central vision needed for reading and close work. Color vision and distance vision are also affected. Apparently, the destructive changes are caused by free radicals, which are created in the retina through exposure to ultraviolet and blue light, found in sunlight.
Fortunately, the body has natural defenses against free radicals: antioxidants. In a study involving people over age 55 who were healthy and eating a diet considered normal for adults, three of four were deficient in two or more of the antioxidants (vitamins C and E and beta-carotene) thought to be important to eye health.