Road running is the sport of running on a measured course over an established road (as opposed to track and field and cross country running). These events are usually classified as long-distance according to athletics terminology, with races typically ranging from 5 kilometers to 42.2 kilometers in the marathon. They may involve large numbers of runners or wheelchair entrants. The three most common IAAF recognized distances for “road running” events are 10K runs, half marathons and marathons. Despite this, there are far more 5K road race events, due to their popularity for charity races and similar, less competitive reasons to hold an event. Road running may offer those involved a range of challenges and interests such as dealing with hills, sharp bends, varied surfaces, inclement weather, and involvement in a large group. Aerobic fitness, or the ability of the body to use oxygen, is the biggest factor contributing to success. The impact of running on roads puts more stress on the feet, knees and lower back than running on dirt or grass. It can compensate by providing a consistent, level surface. It may put less strain on the Achilles tendon.Top 10 Running Surfaces – Runner’s World General Before engaging in road running, one should choose a shoe that best suits one’s foot type and running style. Road running is one of several forms of road racing, which also include road bicycle racing and motor vehicle road racing.