While the date of your birth certificate tells you your chronological age, your health and fitness go a lot further in describing your biological and functional age. In addition, your physical capacity goes a long way in determining the quality of your life. Chronological age is best represented by a person's birthday but is often divided into young, middle, and old age. Biological age is assessed by such variables as muscle strength, bone mineral content, maximal oxygen uptake, or flexibility. All of which are components of physical fitness and all of which can be improved through an appropriate exercise program. A person who is 65 years of age may have a biological age of 45, based on that person's fitness and health status. The converse is also true, I have some college-age students in my classes whose biological age far exceed their chronological age for many physiological parameters. Numerous studies have found that exercise slows the deterioration in function of many of the body's systems. A study on middle-age men by Kasch and colleagues found that the normal 9% to 15% decline in maximal aerobic power and physical work capacity was prevented over a ten-year period of time in the group who followed a regular endurance exercise program. Nakurma et al. found those elderly men who exercised regularly had, on average, a biological age that was 4.7% lower than their chronological age. Generally aging is associated with disability and disease. Most Americans today ultimately die of cancer and heart disease. The Framingham study clearly proved the benefit of exercise in providing better health and longevity. Maintaining a regular fitness program can alter your biological age. Even preventive strategies initiated later in life may help improve the quality of your life. It is becoming increasingly clear that regular, lifelong physical activity is an important component of preventive health strategies. Here is a list of what exercise does to various body systems relative to aging - cardiac output: exercise - increase ; aging - decrease
- blood pressure: exercise - decrease; aging - increase
- blood triglycerides: exercise - decrease; aging - increase
- HDL-cholesterol: exercise - increase; aging - decrease
- muscle strength: exercise - increase; aging - decrease
- muscle endurance: exercise - increase ; aging - decrease
- bone mineral content: exercise - increase ; aging - decrease
- basal metabolic rate: exercise - increase ; aging - decrease
- sleep: exercise - increase ; aging - decrease
- cognitive function: exercise - increase ; aging - decrease
- anxiety and depression: exercise - decrease ; aging - increase
Whether you've been fit your entire life, or like most - sedentary more than active, there's no better time than the present to begin to turn back the clock. Being more active will keep your biological clock slower than the clock on the wall. | 
