Physical activity interventions for children have small impact on overall activity levels and consequently the body fat and mass of children, a study published on bmj.com today suggests. Previous studies have shown that greater activity levels are associated with lower levels of BMI (body mass index) but that physical activity interventions have been unsuccessful in improving children’s BMI. Many previous reviews have not, however, confined their analyses to whole-day activity and some relied on questionnaires rather than objective measures of physical activity like pedometers to measure daily steps taken. This is the first systematic review to measure physical activity using accelerometry devices which provide a measure of total bodily movement across waking hours.
