Abstract
Energy expenditure in 14 fishermen engaged in fishing was determined by direct measurement of oxygen uptake and by indirect assessment based on continuous recording of the heart rate. Urinary excretion of catecholamines was assayed as an index of stress response. The average energy expenditure during all activities on board for the whole work day amounted to the equivalent of about 1 litre O2 uptake per min, corresponding to about 39% of the fishermen's maximal aerobic power, with peaks up to 80%. On the average, about a tenfold increase in epinephrine and a fourfold increase in norepinephrine excretion were observed during work as compared to resting night values.