While increased physical activity has been linked to lower body mass indexes in children, exercise interventions to increase activity levels have little impact on the overall health and activity of children, according to a study recently published in the British Medical Journal.
The findings are the result of a meta-analysis that examined the outcome of 30 exercise intervention trials conducted between 1990 and 2012. The trials, which involved youths 16 years old and younger, lasted at least four weeks and provided participants with additional weekly activity sessions. Rather than increasing the overall amount of time youths spent active, though, researchers found that in some cases these added sessions actually resulted in lower overall activity during the week, and in instances when total activity time did increase, the effect was negligible (overall activity time increased by just four minutes on average) and short-lived.
"Physical activity interventions are not increasing physical activity sufficiently to impact on the body mass or body fat of children," said lead researcher Brad Metcalf, of the department of endocrinology and metabolism at Peninsula College of Medicine and Dentistry in Plymouth, England.
The authors of the study speculated that such exercise interventions might be replacing other opportunities for activity, such as after-school clubs or free play time. Moreover, said director of the Yale University Prevention Research Center Dr. David Katz in response to the findings, the results point to the need for a more encompassing approach to changing exercise behavior.
"We have cause to question if we are doing enough to make routine activity the cultural norm, so that such programming can achieve greater effects," said Katz. "An intervention, no matter how good, can only achieve so much if not surrounded by cultural supports."
