A large percentage of all kids drop out of physical activity by their sophomore year in high school. But the emphasis should be on interesting activity for all students, not just on high-level athletics for the elite few. The second most likely time for activity occurs immediately after school ends. The ASU researches say that such programs should encourage movement and non-competitive activities. Once at home, parents should give their kids and themselves every opportunity for many forms of activity.
Studies show that children with active parents tend to be more active themselves.
If I only had one wish I'd wish for good health. But when push comes to shove, too many people put studying and job success ahead of a legacy of health for themselves and their children.