Daylight savings time tied to more exercise in children

Kids are somewhat more active in the evening when daylight savings time is in effect than when it’s not, researchers report October 23 in the International Journal of Behavioral Nutrition and Physical Activity.

Anna Goodman of the London School of Tropical Medicine and Hygiene and colleagues analyzed data from 15 studies of more than 23,000 children age 5 to 16 years who wore devices on their waists that measured physical activity. The scientists tabulated exercise on days before and after daylight-savings time changeovers, both spring and fall, and accounted for rainy days.

The kids were active 33 minutes a day on average. During daylight savings time, the kids averaged an additional two minutes of moderate-to-vigorous exercise overall. Children’s activity was unaffected in mornings and early afternoons, but kids in Europe and Australia were more active in late afternoon and evening during extended daylight. That effect didn’t show up in children monitored in the United States, Brazil or the Portuguese archipelago Madeira.

The two-minute addition is “modest but not trivial,” the researchers note, since it represents roughly 5 percent more daily activity. That suggests increasing periods of daylight savings time “could yield worthwhile public health benefits,” they argue.