As more Americans turn to walking for fitness, fun, and the pursuit of health, opportunities to participate increase every year. Walkers benefit from relay events specifically designed for them. Walkers also find many exciting opportunities to get off the concrete and blacktop and pursue walking on more natural and yielding surfaces, such as sand, grass, gravel, snow, and mud. As walkers venture off-road, they often experience a totally different physical walking experience than they have previously had on a flat, hard surface. They are challenged by walking up, down, and along hillsides.