Physical working capacity of old workers and physiological background for work tests and work evaluations.

The worker's fitness for different jobs will be determined by a number of functions of which many are influenced by age. The physical working capacity has undoubtedly a maximum between 20 and 35 years of age. The decline after 35 years will be different in every individual, but certain average figures can be given. The reduction is mainly due to a decrease in the maximal values for circulation and respiration rate, that is, in the oxygen-transport system. Also the muscular strength will be reduced in the higher age-groups. The problem in work rationalization is to determine the maximum rate of work that man can carry on continuously and still retain vigour to an advanced age.The result of several work-analyses shows that actually in manual labour the workmen often utilize up to 50% of their aerobic capacity but avoid exceeding this percentage. As the aerobic capacity decreases with age it is important to know the upper limits and the safety margin for the different age-groups. For that reason one has to determine the working capacity of the man and the physiological stress of the job. It is also important to determine to what degree skill and experience can compensate for age-changes. A superior individual will, even in old age, exceed the average of the young. Age differences may often be of less importance than individual differences.It is still not known what physiological qualifications the different jobs demand, or what age-changes in the physiological functions are of importance for these jobs. The gradual increase in the average age of the population makes investigations in this field important.