[Physical work capacity of miners]

The effect of the occupational activity on the physical capacity of work is of great interest for labour physiology. In connection with that, the physical capacity for work of the miners from coal industry, at different age and with different length of service was studied. Submaximum loading of bicycle ergometer was applied--50, 100 and 150 wt. The maximum working capacity was determined by the nomogram of Astrand. The miners, aged from 21-30 (3.4 l/min maximum oxygen consumption) have the highest capacity. At the age of 31-40, it is abruptly dropped (2.54 l/min maximum oxygen consumption) anf is maintained at the same level after that age (2.49 l/min maximum oxygen consumption). The decrease of the physical capacity for work of the miners, over the age of 30, ie greater than the "normal" age decrease as well as than that of the workers from other occupations. The high physical capacity for work of the young miners (to the age of 30) allows the performance of heavy physical work (allowable energy expenditure 5.1 kcal/min, and in peak loading--8.5 Ical/min). The established decrease of the physical capacity for work after that age determines the lower allowable energy loss at work (3.8 kcal/min). The discrepancy between the real physical capacity for work of the workers between 31 and 50 years of age and corresponding allowable energy expenditure as well as the higher energy expenditure determined during work is a circumstance that requires particular attention. In fact, measures intended not to allow the exceeding of the maximum allowable loading are necessary for the older workers.