Prayer walk
A prayer walk is an activity that consists in walking and praying at the same time. It's done not for the physical benefit but for the spiritual exercise, either publicly functioning also as a demonstration or rally (to let other people know the group is praying), or quietly in sight of the subject. For instance, a person or group may be praying for a town or city, and walk the streets of the city while praying, either out loud, or in silence.