Don't worry about the time your teenager appears to be doing nothing. No, not really. All people, older kids included, need fun and exhausting exercise. This may be a team sport offered by Parks and Recreation or the YMCA in your community. Our son's primarily physical activity at ages 16 and 17 was the diving team at our local Parks and Recreation department.
Some kids prefer gardening and shoveling snow and farm-related physical labor.
And there are many adult-oriented groups that may appeal to your older kid, everything from ski club to Toastmasters. Volunteer opportunities for teenagers abound. Check out hospitals, libraries, museums, zoos, radio stations, political campaigns, and so on. Relax What you see during decompression is temporary. You have plenty of time for academics, so bury that vision of the perfectly-run high school down the street.