" 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. 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. A courier delivering a message on foot over 60 miles of road would expend more energy jogging the distance at a 13 minute mile pace rather than briskly walking it at the same pace. Slow jogging is pure exercise, with no practical application. Timex Running Watch Because jogging is inefficient, it's often associated with poor form. Joggers, or runners who are jogging, sometimes move in ways that wouldn't be done in a competitive running situation: excessively bounding into the air, landing heavily on the heel, carrying the arms too high, and so forth. "

" 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. 097 km, 13. 1 miles), or marathon (42. Womens Running Watch195 km, 26. 2 miles), but non-standard distances are also acceptable. "