At age 18, Finnish men have to do compulsory military service for a period ranging from nearly six months to a year, and Finnish women can volunteer to do so.

The Finnish defence ministry announced the start the programme, which aims to promote better physical fitness and a more physically active lifestyle for young men and women of that age.

"The decline in physical activity among young people of conscription age is a serious issue for young people themselves and for society as a whole," Finnish Defence Minister Antti Hakkanen said in a statement.

Data from the check-up conducted on all new recruits when they are called up showed that physical fitness for that age group has been weakening, Ville Isola, who is leading the project, told AFP.

"The number of people in bad shape has increased, while the number of people in good shape has decreased," he said.

"We don't really know why these young people don't move enough," he said.

Over the next two years, the goals are to increase the amount of physical exercise during military service, and to motivate young people to become more physically active, for example by joining sport associations.

The plan is to develop practices that would remain after the project ended.

By having the scheme cover both military service and encourage civilian life choices of conscription-age citizens, Finland hopes it will ensure the country has "a functional reserve also in the future," said Hakkanen.

Two million euros has been put into the scheme, part of a wider project by the government to increase physical activity among all Finnish citizens.