" In the 1960s or 1970s the word "roadwork" was mostly supplanted by the word "jogging" and this form of running became quite popular among many people at that time in the United States. Jogging is a "high-impact" exercise that places strain on the body, notably the joints of the knee . This is actually one of the basic reasons for doing the exercise, as the impact drives growth processes in the body. Some dropped jogging in order to take up "low-impact" exercises such as stair climbing. Jogging can be combined with other kinds of exercising. Special trails that combine them are called trim trails. Some people define jogging as an inefficient form of running which, for the given individual performing it, and all other conditions held constant, is less efficient than walking. Running Bear Lyric Above a certain pace, running is a more efficient form of locomotion (requires less effort). Below that pace, running is less efficient than walking and makes no sense as a means of getting from point A to point B. "

" Anaerobic fitness, that is, the body's capability at responding when there isn't enough oxygen for the muscle, is necessary to charge up hills and past competitors on the finish line. A common saying for runners is that the sport is 90% mental. Recreational running became popular due to high-profile runners such as Steve Prefontaine. Race courses are usually held on the streets of major cities and towns but they could be on any sealed road. Most road races are either 5 km (3. 1 miles), 10 km (6. 2 miles), half-marathon (21. Running Bear Song097 km, 13. 1 miles), or marathon (42. "