Oxygen Consumption (V’O2) and physical Strainas measured by the occupational activity of cleaning personnel

M. J. Fröhlich, R. F. Kroidl, T. Welte

The aim of the study was to determine the physical effort and energy expenditure needed over a working period of 45-60 min, specifically for the occupational activity of cleaning. The effort was demonstrated in absolute terms (V'O2), in relation to the involved person's maximum physical capacity (peak V'O2) and in relation to the individual aerobic-anaerobic threshold (V'O2 at VT1, the point when lactate starts to accumulate but can be cleared). In addition to this, the aim was to verify the suitability of portable ergospirometry in determining the occupational workload in a real-life setting. Thirty-five cleaners performed a bicycle ergospirometry to determine their maximum physical capacity (peak V'O2 = L/min) and their aerobic-anaerobic threshold (V'O2 at the Ventilatory Threshold 1 [VT1]). This was followed by portable ergospirometry lasting 45-60 min while pursuing regular cleaning activities. Performance V'O2 (the average oxygen consumption over 45-60 min of work- time) was 1.06 L/min or 4.4 METs. This was scarcely lower than the individual V'O2 at VT1 and approached 45% of the maximum physical capacity (peak V'O2). In addition, there was positive feedback regarding the wearability of the portable device. The dropout rate was low. The occupational activity of cleaning was defined as a "committed activity", performed close to the upper limit of the continuous physical capacity (approaching V'O2 at VT1). The positive feedback and a low dropout rate proved good acceptance of portable ergospirometry in this field of work over a 45-60 min period.