Longitudinal differences in running endurance and body mass index--a 25-year comparison.

Long-range repeated-measure sample differences in body dimensions, body composition and physical performance help to describe the changes in a population's lifestyle. The aim of our study was to analyse such changes in longitudinal studies repeated after a 25-year interval. Data collections repeated every six months for the periods 1977-1981 (n=152) and 2002-2006 (n=158) were carried out in nonathletic boys aged between 6.51 and 11.50 years from the same districts of Budapest. Means for height, body mass, BMI, body fat percentage, and distance covered during a running endurance test, as well as the slopes of the changes were compared. The children of the second series of studies were significantly taller and heavier, had more depot fat and showed poorer cardio-respiratory endurance than their peers 25 years before. The increases with age in weight, BMI and depot fat were steeper in the second series. The significant differences that developed in anthropometric traits and physical performance during these 25 years are regarded as indirect evidence for how severely the average physical condition had declined, as well as how health risks of the schoolchildren had increased.