Physical inactivity remains the greatest public health problem of the 21st century: evidence, improved methods and solutions using the '7 investments that work' as a framework.

The article discusses various reports published within the issue, including one on seven evidence-based investments for limiting physical inactivity-related disease, another on the link between the physical activity level of adolescents and children and academic achievement and a report on a questionnaire for assessing sedentary behavior in the primary care setting.