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VO2 MAX
- The correct title of this article is VO2 max. It features superscript or subscript characters that are substituted or omitted because of technical limitations.
VO2 max is defined as the highest rate at which oxygen can be taken up and utilized during exercise by a person. (The derivation is V̇ - volume per time, O2 - oxygen, max - maximum). It is also called maximal oxygen consumption or maximal oxygen uptake. Expressed either as an absolute rate in litres of oxygen per minute (l/min) or as a relative rate in millilitres of oxygen per kilogram of bodyweight per minute (ml/kg/min), the latter expression is often used to compare the performance of endurance sports athletes. VO2max is genetically predetermined for the most part, though it may be improved by several percentage points with training.
Measuring VO2 max
Accurately measuring V̇O2 max involves a ramp test (either on a treadmill or on a cycloergometer) in which exercise intensity is progressively increased until exhaustion while measuring the rate and oxygen concentration of the inhaled and exhaled air.
Dr. Kenneth H. Cooper conducted a study for the United States Air Force in the late 1960s. One of the results of this was the Cooper test in which the distance covered running in 12 minutes is measured. An approximate estimate for VO2 max is:
- VO2 max = (distance (in metres) covered in 12 minutes - 505)/45
There also exist several other reliable tests to estimate VO2 max.
VO2 max is properly determined by the Fick Equation: VO2 max = Q(CaO2-CvO2) where Q is the cardiac output of the heart, CaO2 is the arterial oxygen content, and CvO2 is the venous oxygen content.
VO2 max varies considerably in the population. The average young untrained male will have a VO2 max of approximately 3.5 litres/minute and 45 ml/min/kg. The average young untrained female will score a VO2 max of approximately 2.0 litres/minute and 38 ml/min/kg. These scores can improve with training and decrease with age.
In sports where endurance is an important component in performance, such as cycling, rowing, cross-country skiing and running, world class athletes typically have high VO2 maximums. World class male athletes, cyclists and cross-country skiers typically exceed 80 ml/kg/min and a rare few may exceed 90 ml/kg/min for men and 70 ml/kg/min for women. Three times Tour de France winner Greg LeMond is reported to have had a VO2 max of 92.5 at his peak - one of the highest ever recorded. By comparison a competitive club athlete might achieve a VO2 max of around 70 ml/kg/min. World class rowers are the physically largest endurance athletes and typically do not score as high on a per weight basis, but often score exceptionally high in absolute terms. A less size-biased measure is to divide by mass(2/3) rather than mass. Male rowers typically score VO2 maximums over 6 litres/minute, and some exceptional individuals have exceeded 8 l/min.
To put this into perspective, thoroughbred horses have a VO2max of around 180 ml/min/kg.
See also
External links
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