“This comes on the one hand from people getting more done during the hours they are at work, and on the other hand, from less absenteeism owing to sickness,” Ulrica von Thiele Schwarz and Henna Hasson, researchers behind the study in a statement, said in a statement.

A large Swedish dental organisation took part in the study and employees from a total of six work places were divided up into three groups.

One group was asked to devote 2.5 hours to physical activity, distributed across two sessions a week.

The second group had the same decrease in work hours but without the obligatory exercise, and a third group maintained their usual 40 hours work a week.

All employees retained the same salaries and the workload of the practice, in this case the number of patients treated, remained the same while study was being carried out.

The study showed that all three groups were able to maintain or even increase their production level during the study compared with the corresponding period the previous year.

Those who exercised also reported improvements in self-assessed productivity – they felt they got more done at work and had a greater capacity for work, as well as being absent from work less often.

A total of 177 participated in the study to its completion which lasted for 12 months.

Participants were asked to fill in a questionnaire at the beginning, mid-term and end of the study period.