" Competitive running Perhaps the most basic of athletic contests, running races are simply contests to determine which of the competitors is able to run a certain distance fastest. Today, competitive running events make up the core of the sport of athletics . Running competitions have probably existed for most of humanity's history, and were a key part of the ancient Greek Olympics, as well as the modern Olympic games. Events are usually grouped into several classes, each requiring substantially different athletic strengths and involving different tactics, training methods, and types of competitors. Running affects not only the body, but the mind as well. Runners who finish a great run are often said to have a "runner's high" - a strong feeling of accomplishment and pride. Some sources point to the origin of a runner's high being increased endorphin production as a result of exercise. Dallas Cowboys Running Back Running injuries There are many injuries associated with running (due to it being a high impact activity). Common injuries are "runner's knee" (pain in the knee), shin splints, pulled muscles (especially the hamstring), "jogger's nipple" (soreness of the nipple due to friction), twisted ankles, and Iliotibial Band Syndrome. "

"4 km (5. 2 miles), the SBLI Falmouth Road Race in Falmouth Cape Cod is 7 miles long, San Francisco's "Bay to Breakers" is 12 km (7. 46 miles); "City to Surf" in Sydney, Australia is 14 km, Honolulu's "Great Aloha Run" is 8. 15 miles (13. 12 km), and the "Charleston Distance Run" in Charleston, West Virginia is 15 miles (24. 14 km). Any running that covers a distance further than a marathon is called ultrarunning; the event is an ultramarathon. Best College Running Back Such events can be measured in distance (for example, 100 kilometers) or by time (whoever has run the farthest after 24 hours). Examples include the London to Brighton run in England which is just over 54 miles (87. "