Chronological aging starts at birth and ends at death. Therefore, anyone in the work force (15–64 years of age) can be considered an aging worker. However, the definition of an aging worker is generally based on the period when major changes occur in relevant work related functions during the course of work life. Functional capacities, mainly physical, show a declining trend after the age of 30 years, and the trend can become critical after the next 15–20 years if the physical demands of work do not decline. On the other hand, workers' perceptions of their ability to work indicate that some of them reach their peak before the age of 50 years, and five years later about 15–25% report that they have a poor ability to work, mainly those workers in physically demanding jobs but also those in some mentally demanding positions.1Therefore, the ages of 45 or 50 years have often been used as the base criterion for the term “aging worker”. The main reason for the “early” definition of aging among workers from the occupational health point of view is that it gives better possibilities for preventive measures. The need for early action has been emphasised by the low participation rates of workers who are aged 55 years or older and by the early exit of this age group from work life all over the world.