Physical Fitness, Physical Activity and Obesity Among Children and Youth

Purpose To evaluate the differences in physical fitness and physical activity between 9- and 15-year old girls and boys in Oslo, and to evaluate the relationship of those variables with obesity.

Methods Four hundred and ten 9-year olds and 347 15-year olds participated in a cross-sectional study as a part of the European Youth Heart Study. Cardiorespiratory fitness (VO_2peak) was indirectly measured using an incremental, maximal bicycle ergometer test. The Computer Science and Application (CSA) activity monitor was used to register physical activity. As a measure of obesity the skinfold thickness was registered at four sites with a Harpenden caliper.

Results Significant differences (p <0.1001) were observed regarding VO_2peak physical activity and the sum of four skinfolds between girls and boys in both age groups. The level of physical activity was also significantly lower in the oldest cobort than in the youngest one. The sum of four skinfolds showed a significant correlation with physical fitness for both girls and boys in the two age groups This correlation could not be found for physical activity.

Conclusion Our results support today’s knowledge that boys are more physically active than girl and that the physical activity revel decrease with increasing age. It is therefore of importance to provide action toward those children who are least physically fit and simultaneously prevent the general physical activity level to decline.