"Aerobic fitness" means the ability to carry on work for a long period. It increases the amount of oxygen that is delivered to our muscles, which allows us to work for longer periods. An activity which raises our heart rate and keeps it up for an extended period of time will ultimately improve our aerobic fitness.This is usually experienced in the abilities to walk, run, climb uphill, swim, etc. Most forms of sports, work, recreational and military activities include elements of aerobic fitness.
Generally speaking, any activity which lasts less than 12 minutes is not fully aerobic. Strenuous exercise lasting less than 12 minutes includes substantial portions of anaerobic metabolism whereby one uses energy sources stored in the body to perform the work. Since the body`s energy sources are limited, anaerobic work cannot last long. Fast runs, lasting 10 to 15 seconds, are mostly accomplished by anaerobic metabolism. With longer exercise time, more aerobic metabolism is involved, and exercise lasting more than 12 minutes is mostly accomplished by aerobic metabolism.
In aerobic work, oxygen is obtained from the air and is transferred from the lungs to the blood and then to the muscles via the circulatory system. Maximal oxygen uptake, or maximal aerobic power ( Vo2 max ) is the indicator of aerobic fitness. Vo2 max is determined by the measurement of oxygen uptake during the performance of maximal work, typically while running on a treadmill or while cycling. Aerobic fitness is dependent upon age and sex and it can be improved by training. It is highest at ages 18, 19 years in males and 15 to 20 years in females, and it decreases with age in adulthood. In general, males have higher Vo2 max than females. The main reason for this is that aerobic fitness is directly related to fat-free body weight, which consists mainly of the weight of muscles in the body, and on the average, males have a higher muscle mass than females. As with other physiological functions, there are large individual differences in Vo2 max of people of the same sex and age. Some people show high Vo2 max without exercising because of genetic and other factors, while other people who exercise regularly do not show high Vo2 max.
Importance of Aerobic fitness
- Aerobic fitness determines the degree of fatigue that almost everybody experiences in daily life. The higher your aerobic fitness, the less fatigue you experience.
- It is the most important asset in emergency situations in crises such as floods, earthquakes, fires, and other crises. The ability to reach safety or to survive under such circumstances may depend upon one`s endurance in walking, running, swimming, climbing, and similar activities.
- It plays an important role in growth and development during childhood and adolescence. A high level of aerobic fitness during the growing years indicates good development of the muscles, bones, and cardio-respiratory system. It is more important in this respect than body weight.