I love this reason:
1. Walking boosts your mood even when you’re not expecting it. In a recent study, researchers conducted three experiments on hundreds of college students to find out if they’d experience a positive mood boost while walking, without knowing that walking could be the reason. The researchers disguised each experiment as an alleged test of something else, all the while tracking mood changes linked to the simple act of taking a stroll. They found that just 12 minutes of walking resulted in an increase in joviality, vigor, attentiveness and self-assurance versus the same time spent sitting.