A new study by researchers at the WHO attempts to throw some insight into how many boys and girls, between the ages of 11-17 years, are physically active across the globe. The study, published in the journal The Lancet Child and Adolescent Health, analysed data from 1.6 million students in that age group during the years 2001-2016. It found that most adolescent boys and girls—four in five—aren’t as physically active as they ought to be in 2016.