There's something to be said for muscle confusion. Mixing up your workout has been credited with yielding greater fitness benefits as well as preventing injury--but in our opinion, what's most notable about switching up your sweat sesh is that it keeps things interesting! There's nothing worse than going to the gym and running on the treadmill or using the elliptical for an hour EVERY DAY. We also think that there is something to be said with changing up your surroundings. That said, we've rounded up 7 great workout circuits you can do at a park nearby you. The best part? No equipment necessary and you can get your tan on while you work!