Physical fitness has four components:
- Aerobic (cardiovascular) fitness - The
body's ability to take in and use oxygen to supply energy throughout the body
- Muscular fitness - The strength and
endurance of muscles
- Flexibility - The ability to move joints
and stretch muscles fully through their normal range of motion
- Body composition - The amount of fat
tissue in relation to other tissue in the body
Aerobic (or cardiovascular) fitness is one of
the most important components of overall physical fitness.
It reflects the amount of oxygen in the blood
pumped by the heart and transported to the working muscles,
as well as the
muscles efficiency in using that oxygen.
When you're working hard,
your bodys metabolism increases. When faced with increasing energy demands,
your body eventually reaches a limit for oxygen consumption/uptake (represented
as VO2). At this point VO2 reaches a peak value referred
to as your aerobic capacity, or maximal oxygen uptake (maximal aerobic power,
Increasing your aerobic fitness means increasing
your heart and cardiovascular systems capacity to perform their most important
task, supplying oxygen and energy to your entire body.
The best way to
improve your aerobic fitness is through activities that put the body´s
large muscle groups to work dynamically-for example, walking, jogging, running,
swimming, skating, cycling, stair-climbing and cross-country skiing.
Although your exercise habits have a big affect on your aerobic fitness,
it's also related to age, gender and heredity. Maximum fitness values occur
between the ages of 15 and 30, decreasing progressively with age. With a
sedentary lifestyle, VOmax decreases by 10% per decade-but if you maintain an
active lifestyle, you can bring that number down to less than 5% per