Do a workout at the park. Find a path that has an adequate amount of benches for instance. You can do different drills between benches:
- High knees
- Butt Kickers
- Lunges
- Squat Jumps
- Sprints
- Bear-crawls
And every time you get to a bench, the exercise door opens again:
- Push ups
- Close grip Push ups
- Dips
- Step Ups
- Jump Ups (make sure the benches are sturdy enough)
Do a workout in your yard. There are plenty of body-weight based exercises for which you do not need a gym or any equipment for that matter: You'll be surprised how good of a workout you'll get.
- Jumping Jacks
- Burpees
- Push Ups
- Sit Ups
- Planks
- Sprints
- Lunges
- Squats
- Bear-crawls
- Squat jumps
- etc.
Go for a interval based bike ride. Find a path with some hills. Sprint on the way up and coast on the way down. Why not stop in between for a quick set of burpees and push ups?