Washington D.C.: Dear parents, ask your kids to exercise daily from early childhood, as a study warns that level of physical activity may start tailing off as early as the age of seven, rather than during adolescence, which is widely believed. The study was published online in the British Journal of Sports Medicine.
"The present study found that 100 percent of boys and girls fitted into longitudinal trajectories which were inconsistent with the orthodox view that physical activity begins to decline at adolescence, declines much more rapidly at adolescence and/or declines much more rapidly in adolescent girls than boys," the researchers explained.
"The study questions the concept of the adolescent girl as a priority for research and policy efforts in physical activity," they pointed out. They tracked the physical activity levels of a representative sample of around 400 children over a period of eight years (2006-15).
The physical activity levels were measured when the children were seven, nine, 12 and 15, using a small lightweight portable monitor (Actigraph), worn for seven days at a time. Overall, the total volume of physical activity fell from the age of seven onwards in both boys and girls during this time, with declines no steeper during adolescence than in earlier childhood.
The study found that in 61 percent of boys, moderate levels of physical activity gradually tailed off from the age of seven. However in girls, moderate levels of physical activity that gradually tailed off from the age of seven were 62 percent.
"Future research and public health policy should focus on (A) preventing the decline in physical activity which begins in childhood, not adolescence, and (B) providing an improved understanding of the determinants of the different physical activity trajectories, including an understanding of the relative importance of biological and environmental influences," they emphasised.