AGE AS A FACTOR IN PHYSICAL FITNESS
People undergo many changes as they grow older. For example,
the amount of blood the heart can pump per beat and per minute
decreases during maximal exercise, as does the maximum heart rate.
This lowers a person's physical ability, and performance suffers.
Also, the percent of body weight composed of fat generally increases,
while total muscle mass decreases. The result is that muscular
strength and endurance, CR endurance, and body composition suffer.
A decrease in flexibility also occurs.
Men tend to maintain their peak levels of muscular strength
and endurance and CR fitness until age 30. After 30 there is a
gradual decline throughout their lives. Women tend to reach their
peak in physical capability shortly after puberty and then undergo
a progressive decline.
Although a decline in performance normally occurs with aging,
those who stay physically active do not have the same rate of
decline as those who do not. Decreases in muscular strength and
endurance, CR endurance, and flexibility occur to a lesser extent
in those who regularly train these fitness components.
People who are fit at age 40 and continue to exercise show
a lesser decrease in many of the physiological functions related
to fitness than do those who seldom exercise. A trained 60-year-old,
for example, may have the same level of CR fitness as a sedentary
20-year-old. In short, regular exercise can help add life to your
years and years to your life.