Oxygen consumption of lumberjacks in logging with a power-saw

Abstract

To study the cardiovascular load and strain in logging, oxygen consumption was measured with portable equipment in 15 loggers at work both in the autumn and the winter. In addition, heart rate was measured telemetrically in six loggers in the winter. The mean age of the loggers was 34 years; they used a power-saw and were paid on a piecerate basis. When the logger worked at his own pace at a range of tasks the oxygen consumption was 1.9 ± 0.3 1/min (mean ± S.D.) in both seasons. This corresponded to 49 ± 7% of the maximal oxygen consumption obtained in a treadmill exercise test. Oxygen consumption during bunching of wood (2.2 ± 0.3 1/min) was higher than that of either felling or limbing and bucking in both seasons. The heart rate in logging was 123 ± 4 beats/min in the winter, which corresponded to 66% of the maximal heart rate in the exercise test. The heart rate was higher in bunching than in other working phases. The wages, the daily output of wood produced by the loggers and the type of wood lots did not differ between autumn and winter. Using regression analysis, various factors of work difficulty reflecting external working conditions had no association with the oxygen consumption at work. Based on the classification of the World Health Organization, motor-manual logging was physically heavy. There were no marked differences in the oxygen consumption of logging work between the two seasons.