Fitness can be measured by the volume of oxygen you can consume while exercising at your maximum capacity. VO2max is the maximum amount of oxygen in millilitres, one can use in one minute per kilogram of body weight. Those who are fit have higher VO2max values and can exercise more intensely than those who are not as well conditioned. Numerous studies show that you can increase your VO2max by working out at an intensity that raises your heart rate to between 65 and 85% of its maximum for at least 20 minutes three to five times a week. A mean value of VO2max for male athletes is about 3.5 litres/minute and for female athletes it is about 2.7 litres/minute.
Factors affecting VO2max
The physical limitations that restrict the rate at which energy can be released aerobically are dependent upon:
- the chemical ability of the muscular cellular tissue system to use oxygen in breaking down fuels
- the combined ability of cardiovascular and pulmonary systems to transport the oxygen to the muscular tissue system