It’s well-known that African American adolescent girls have a higher prevalence of obesity than Caucasian or Asian adolescents. And it’s widely understood that in part this is because they are often less physically active than their peers. But the question of why they are less active has always been a bit of a puzzle. There are probably many factors at play, not least the fact that many African American kids grow up without access to the facilities, coaches and leagues that are simply a part of life for kids from wealthier families.