If you've ever returned home from a yoga class, a walk with neighbors, or a friendly pickleball game with some extra pep in your step, you've experienced firsthand the mood-boosting benefits of group exercise. What you might not realize is that by gathering with others to move and sweat, you've unknowingly tapped into the power of the "third space." To continue reading this article, you must log in . Subscribe to Harvard Health Online Plus (HHO+) to unlock expert-backed health insights,