London, May 15 (IANS): Physically demanding jobs are linked to shorter working lives, more sick leaves and unemployment than jobs that don't rely on muscle and heavy exercises, say researchers.

For the findings, published in the journal The BMJ, the researchers looked at the working life expectancy of 1.6 million people in Denmark between the ages of 18 and 65 who had a job as of November 2013.

The level of physical demand required for each person's job was measured by the job exposure matrix or JEM for short. This covers 317 different types of occupation. The JEM score was categorised as low physical demands (below 16); moderate (16-28); and high (28 plus).

"This study showed that high physical work demands are a marked risk factor for a shortened expected working life and increased years of sickness absence and unemployment," the study authors from National Research Centre for the Working Environment in Denmark, wrote.

Jobs scoring high, included those in construction; manual labour, such as carpentry, masonry, painting and plumbing; cleaning; and manufacturing industries.

Periods of sick leave, unemployment, and disability pension payments were recorded for each participant for the next four years until 2017.

The final analysis is based on workers aged 30, 40, and 50. It showed that more men than women were categorised as having very physically demanding jobs according to the JEM score. Men in this group were, on average, nearly three years younger than their peers in physically undemanding jobs. Women, on the other hand, were around 10 months older. For both sexes, a physically demanding job was strongly associated with shorter working life expectancy, and more sick leaves and unemployment compared with a physically undemanding job.

At the age of 30, working life would be expected to last almost 32 years for men with physically demanding jobs and nearly 34 years for men with physically undemanding jobs. Among women, the equivalent figures were just over 29.5 years and nearly 33 years, respectively.

In all, a 30-year-old woman would be expected to have three fewer years of working life; 11 more months of sick leave; and 16 more months of unemployment, the analysis showed.

The equivalent figures for a man would be two years; and 12 and eight months, respectively.

The researchers point out that there are likely to be other factors in the ability to work, which were not accounted for in this analysis, including lifestyle factors, such as obesity and smoking, as well as long term conditions.