A clear link exists between oxygen consumption (VO2) of the body and cardiorespiratory fitness because oxygen delivery to tissues is dependent on lung and heart function. VO2max (maximal oxygen uptake, maximal aerobic power) is the maximal rate at which oxygen can be used by the body during maximal work; it is related directly to the maximal capacity of the heart to deliver blood to the muscles. VO2max can be measured or predicted by fitness tests (e.g. maximal tests, submaximal tests, Polar Fitness Test). VO2max is a good index of cardiorespiratory fitness and a good predictor of performance capability in aerobic events such as distance running, cycling, cross-country skiing, and swimming.
VO2max can be expressed either as milliliters per minute (ml/min = ml ■ min-1) or this value can be divided by the person’s body weight in kilograms (ml/kg/min = ml ■ kg-1■ min-1).
The relationship between oxygen uptake (VO2) and heart rate (HR) is linear within an individual during dynamic exercise. Percentages of VO2max can be changed to % of HRmax with the following formula: %HRmax = (%VO2max + 28.12)/1.28.
VO2max is the basic variable of the intensity of exercise. When determining target exercise intensities heart rate is more practical and useful because it is easily and noninvasively obtained, e.g. on-line during exercise with heart rate monitors.