[Lactate threshold and the physiological cost of work]

Mean values for body size, fitness and endurance performance indices have been obtained from 20 industrial workers. Then the pulse rate from ECG using the Holter method during the worktime was registered and from the regression line PF on load energy expenditure was calculated. The "somatic" and "fitness" indices of subjects were not statistically significantly different from average workers population in Poland. The mean AT demonstrated that the subjects were able to perform hard work without metabolic acidosis developing, though those exhibiting lower AT worked with higher physiological cost of work. The study confirmed that the Holter method is extremely good for energy expenditure investigation during the worktime. Furthermore it was demonstrated that the physiological cost of moderate-heavy work was lower in subjects with higher AT. The authors suggested that the level of AT for medium-fit workers should come to about 2 dm3(02) X min.-1 (60%v02 max.