VALIDITY OF OXYGEN CONSUMPTION MEASUREMENT AT THE WORKPLACE: WHAT ARE WE MEASURING?

The measurement of oxygen consumption ( $V˙$ o ₂ ) is generally put forward as the most accurate method for estimating the work load at a given work site. A study was conducted to compare, for two groups of 12 workers, the results of $V˙$ o ₂ measurements during a 30-min period with the data provided by a continuous recording of the heart rate over a whole shift. Results show that the measured metabolic rates may be unrepresentative of the working situation. From a joint recording of HR levels during the whole shift, this representativeness could be assessed. If both techniques cannot be carried out, preference must be given to the continuous HR recordings, as they enable one to analyse the cardiovascular strain due to the work both at a given time in correlation with the work done and in average over the whole working period.