Parents who are active during pregnancy and early in their child's life tend to raise more active children, finds a study published on bmj.com.
Some risk factors for adult diseases are associated with lower levels of physical activity in children. Associations have also been reported between early life factors (from birth to around five years) and childhood obesity.
But little is known about the early life influences on children's physical activity.
So researchers identified children aged 11 to 12 who were taking part in the Avon Longitudinal Study of Parents and Children (ALSPAC). Each child was asked to wear an accelerometer for seven days, which recorded minute by minute the intensity and frequency of physical activity.
Valid data, defined as at least three days of at least 10 hours per day, were collected from 5,451 children and were analysed against various factors hypothesised to affect physical activity.
Several factors showed a modest association with later physical activity. These included mother's activity during pregnancy (specifically brisk walking and swimming), season of birth, one or both parents' physical activity when the child was aged 21 months, and having an older sibling.
The authors explain that the link with mother's activity during pregnancy is unlikely to be due to biological factors inside the womb. Instead, mothers who are physically active during pregnancy are likely to keep active after pregnancy, and that this in turn influences children's physical activity.
The association with season of birth is difficult to explain, they add, but it may be linked to school starting age.