Answer: 16.7%
Explanation: Children and adolescents (ages 6 to 17 years) engage in 60 minutes or more of moderate-to-vigorous physical activity daily as described by the CDC in The Physical Activity Guidelines for Americans (second edition).
However, elementary and high schools usually run from 8 a.m to 3 pm (or 3.30pm in some cases) daily. High school students take six one-hour classes or four 90-minute classes and an hour lunch break daily.
Thus, the CDC recommends 60minutes of physical activities daily, which account to 16.7% of the total class duration (6 hours) per day.