" 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. 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. The most common running related injuries are due to over-use. Jeep Grand Cherokee Running Boards Repetitive stress on the same tissues without enough time for recovery or due to improper form or muscle imbalances, leads to many of the above. Generally these can be minimized by warming up beforehand, wearing proper running shoes, improving running form, performing strengthening exercises, and getting enough rest. "

" Types of running events Track running Road running Cross-country running Trail running Fell running Classification of running by distance Sprints Middle distance Long distance Ultrarunning Silent Running is a science fiction movie made in 1972, directed by Douglas Trumbull and starring Bruce Dern as the protagonist Freeman Lowell. It was made with a very limited budget but has since achieved a cult following. The movie depicts a dystopian future, in which all plant life on Earth is extinct and only a few specimens have been preserved in greenhouse-like domes attached to a fleet of three American Airlines "Space Freighters" positioned just outside of the orbit of Mars. Lowell, a crew member aboard one of these ships, the "Valley Forge", is in constant disagreement with his other, human crewmates, who are anxious to return to a bleak and deforested yet familiar Earth. However, Lowell does have a better relationship with humanlike drones who are also aboard the ships. The science and technology depicted in Silent Running are not always plausible, and Trumbull's special effects are low quality even by the standards of the time (he had a larger budget in his later film Blade Runner), but the melancholy message is powerful. The soundtrack songs are performed by Joan Baez and the film score was composed by Peter Schickele. Ici Running Boards Spoiler warning: Plot or ending details follow. When orders come from Earth to jettison the domes that contain the plants, blow each of them up via nuclear explosions and return, Freeman Lowell decides it is his mission to save the plants on his ship, the "Valley Forge. "