Dunton GF, Liao Y, Almanza E, Jerrett M, Spruijt-Metz D, Chou CP, Pentz MA. Joint physical activity and sedentary behavior in parent-child pairs. Med Sci Sports Exerc. 2012 Aug; 44(8):1473-80.

Purpose
The research examined joint physical activity and sedentary behavior among 291 parent-child pairs who both wore an accelerometer and Global Positioning System (GPS) device during the same 7-d period.

Methods
Children were 52.2% female, 8-14 yr, and 43.0% Hispanic. Parents were 87.6% female. An ActiGraph GT2M accelerometer and GlobalSat BT-335 GPS device collected activity and global positioning data, respectively. Linear distance between the parent and child for each 30-s epoch was calculated using geographic coordinates from the GPS. Joint behavior was defined as a separation distance less than 50 m between parents and children.

Results
On average, during nonschool waking hours, parents and children spent 2.4 ± 4.1 min·d (mean ± SD) performing moderate-to-vigorous physical activity (MVPA) together and 92.9 ± 40.1 min·d in sedentary behavior together. Children engaged in an average of 10 min·d of MVPA during nonschool waking hours when their parent was nearby but not engaging in MVPA. During this same period, parents engaged in 4.6 min·d of MVPA when their child was nearby but not engaging in MVPA. Household income level and the child’s age were negatively associated with joint MVPA. Girls engaged in a greater percentage of their total MVPA together with their parent than boys. Girls and older children engaged in more sedentary behavior together with their parent than boys and younger children. Older parents engaged in a greater percentage of their sedentary behavior together with their children than younger parents.

Conclusions
Replacing the time that parents and children spend together in sedentary pursuits with joint physical activity could have health benefits, especially for girls, older children, older parents, and higher income families.