On principle, I really enjoy walking with a pipe, but I mostly smoke a pipe indoors. My walks usually last longer than a bowl of tobacco, and a bowl tends to burn faster when you are out walking because of the breeze or wind. A slow saunter is best of smoking a pipe, whereas a more brisk walk is better for exercise. I do enjoy the challenge of lighting or relighting a pipe in the wind, using trees, berms or other obstacles to block the wind. It is almost a sport to itself. Walking is even better for mind-tripping; you have creative ideas, remember things you have to do that you'd forgotten, and generally stimulate your mind. You get a slightly different mind trip when you smoke a pipe, which also demands attention.