Secular trends in body dimensions and physical fitness among adolescents in Sweden from 1974 to 1995

Abstract

Aim: To investigate changes over time in body dimensions, and muscular and aerobic fitness in a representative sample of 16-year-old-girls and boys in secondary schools in Sweden from 1974 to 1995 (n = 855).Method: Height and weight were measured and five tests were performed: run–walk, two-hand-lift, Sargent jump, sit-ups, and bench-press.Results: In 1995, girls and boys had higher body mass index (BMI) than in 1974. Girls and boys performed less well in bench-press, sit-ups, and run–walk-tests in 1995. Boys, but not girls, performed better in Sargent jump in 1995 than in 1974. Girls and boys performed better in two-hand-lift in 1995 than in 1974. However, after adjustment for body dimensions, there were no differences in performance in two-hand-lift or run–walk-tests between 1974 and 1995.Conclusion: There was a decreased aerobic fitness and an increased maximal static strength among adolescents in Sweden between 1974 and 1995. These changes were partly due to increased BMI. However, decreased daily physical activity level cannot be excluded as a contributing factor to the decreased aerobic fitness. The reduced performance in muscular endurance in 1995 was not related to increased BMI. Instead, it is suggested that it is to be related to a specific decrease in hip flexion and arm muscle endurance.