Practical considerations in the testing of VO2max in runners.

Maximal oxygen intake (VO2max) may be the most physiologically significant and, therefore, the most commonly measured parameter in the physiological assessment of well trained runners. To insure valid and reliable VO2max values, there are a number of practical concerns that must be addressed. An exercise modality must be selected that activates the specific muscle mass and duplicates the motion utilised in the runners' training programme. Motorized treadmill running has been shown to allow the most efficient, valid and reproducible VO2max values in a controlled testing environment. A testing protocol must be used that is easily administered, comfortable for the runner, allows test completion within 10 minutes, uses grade increments at a constant speed, and is reproducible. Speeds should be selected that approximate the runner's training pace. The criterion for the attainment of VO2max include the levelling off of VO2 with an increase in work stage, the onset of extreme exhaustion, the respiratory exchange ratio exceeding 1.1, blood lactate levels approaching or exceeding 10 mmol/L, and ratings of perceived exertion of 19 or 20. Quality control in terms of standardisation of procedures and calibration and maintenance of equipment is essential for the minimisation of technological error. Measurement equipment must be affordable, dependable, easily calibrated, yield reproducible data, and be within the technical skill levels of the operating personnel.