The repeatability of the measurement of aerobic power in man and factors affecting it.

The repeatability of measuring man's aerobic power was tested with regard to the influences from the following; 1. The immediate repeatability of the test. 2. The time sequences in which the progressive load increments are applied. 3. The subject's personal activities in the eighteen hours prior to the test. 4. The temperature of the laboratory during the test. 5. The time of day at which the test is carried out. 6. The day of the week on which the test is carried out. 7. The nervous state of the subject during the test produced by drugs affecting the autonomic nervous system. It was considered that aerobic power can be consistently measured in man as a standard control measurement if the following criteria are taken into account. The subject should be tested: 1. during the first few hours of his working day, 2. in an ambient temperature of not more than 4 degrees C above that of his normal working environment, 3. when he has been normally active during the previous 24 h, 4. when he is systematically free from drugs, particularly those affecting the nervous system, 5. when free from a previous severe stress, 6. at least 1 h after a cigarette or contact with a smoke aerosol.