Do 3 seasons of school sports--sports that will enhance physical fitness and mental toughness.
Some options are:
Fall
1. Cross Country
2. Football
3. Soccer
4. Volleyball
5. Golf
Winter
1. Basketball
2. Wrestling
3. Track
4. Bowling
Spring
1. Track
2. Lacrosse
3. Baseball
4. Tennis
If you're good at golf and bowling, then join those teams, but those sports by themselves provide no effective conditioning. Baseball's a sport you get decent anaerobic workouts for, but do other spring sports if fat loss is your goal.
Recommended combos are:
1-1-1 Cross Country/Basketball/Track
3-1-2 Soccer/Basketball/Lacrosse
2-2-2 Football/Wrestling/Lacrosse
2-2-1 Football/Wrestling/Track
3-3-1 Soccer/Track/Track
1-3-1 Cross Country/Track/Track
2-1-2 Football/Basketball/Lacrosse