Purpose: This population-based study describes fitness profiles in aerobic capacity (N = 387088) during the years 1975-2004, muscle performance (N = 280285) from 1982 to 2003, and body anthropometry (N = 324911) from 1993 to 2004 among the Finnish conscripts at the age of 20 yr.
Methods: Endurance performance was tested by the 12-min running test. Muscle fitness tests consisting of sit-ups, push-ups, pull-ups, a back-muscle test, and standing long jump were scored to muscle fitness index (MFI).
Results: The mean body mass of the conscripts increased from 70.8 to 75.2 kg (P < 0.01) during the years 1993-2004. The mean distance of the conscripts" 12-min running test increased first by 4% from 1975 to 1979, but after it that decreased by 12% (from 2760 m to 2434 m, P < 0.001) compared with the year 2004. MFI increased during the first decade of the follow-up, but thereafter, the number of conscripts who achieved excellent and good MFI decreased from 66.8 to 41.2% (P < 0.001) during the years 1992-2004. The physical ability of the conscripts to meet military service declined during the last 15 yr.
Conclusion: Both the increase in body mass and the decrease in physical fitness may lead to serious health problems in the future.