Tracking of pedometer-determined physical activity: a 5-year follow-up study of adolescents in Sweden.

Tracking refers to the tendency for individuals to maintain their rank in a group over time. The authors explored tracking of pedometer-determined physical activity. In October of 2000, 2003, and 2005, data of physical activity as steps per day were collected with sealed Yamax SW-200 pedometers (Tokyo, Japan) for 4 consecutive schooldays in 97 (46 boys and 51 girls) Swedish adolescents (mean age 12.7 in 2000). In general, tracking of pedometer-determined physical activity was low to moderate during adolescence. A sex difference, with boys expressing higher tracking, was seen. Moderate tracking was seen in the individuals who, according to recommendations, were insufficiently active.