" 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. Discount Running Apparel 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. "

" For these reasons, "jogger" and "jogging" are considered derogatory terms by some athletes who consider themselves runners. Other people use the terms "running" and "jogging" interchangeably, and see nothing derogatory about "jogging". Jogging is also used for active recovery intervals during interval training. The runner who may just have completed a fast 400 meter repetition at a sub-5-minute mile pace, may drop to an 8 minute mile pace for a recovery lap. The jog might be carried out in much poorer, looser form whose purpose is to "shake out" the body and maintain circulation to eliminate the waste products of exercise metabolism. 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. Man Running Apparel 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. "