For a serious runner intending to participate or compete in a road race, road or track running is crucial for success. The most intrinsic difference between road and treadmill running is the function of the runners center of mass; on a treadmill the center of mass is static, as its main function is to keep the runner from falling backward with the tread, whereas on the road, the center of mass depends on the runner to propel it forward. The propulsive forces the runner must initially create by the leg as it pushes off the ground propels the center of mass forward, and repeats with each gait cycle as the runner continues to accelerate and decelerate her center of mass with each step of her run. Instead of producing propulsive forces to move the center of mass on treadmill, the runner is attempting to keep the center of mass stable.
Less scientific benefits to road running include the advantages of incline and variant surfaces. Inclines are crucial to a runner's progression, as different muscles are used at each grade of incline; even if distance is the main goal, hill-trained muscles give the runner a a powerful advantage and decreases muscle fatigue. The variation of surfaces, such as track, pavement, dirt, sand and grass are beneficial to joints that face repetitive pounding motions. Scenery, fresh air and exploration are, though subjective, also benefits to outdoor running.
For many, the treadmill at times is the only option, and regardless of preference for tread or road, most runners agree that treadmill running is better than no running. The treadmill does have its own distinct advantages. In regions where outdoor running is not always possible due to meteorological conditions such as heat or severe cold, ice, snow and rain, the treadmill is a great alternative to a slip on the ice or a bout of heat stroke. The mill is also a valuable tool for sprint work, and for runners living in flat regions, the incline feature of most mills allow for hill training when otherwise impossible.
Many runners make mistakes both both on the road and on the treadmill. The number one mistake treadmill runners make is the use of the hand rails; the ultimate objective of a treadmill is to imitate road running, therefore whatever is not available out in the open should not be used while on the treadmill. Holding on to the machine while running affects form, cadence and lessens the leg muscles' function. If holding the hand rails proves necessary during any stage of the run, then the speed of the belt needs to be decreased. The attention to form and cadence is particularly crucial to treadmill running; improper form and cadence on the treadmill can transfer and affect road running performance.
A common misconception in treadmill running is distance ability. A runner who can run five miles on a treadmill is not necessarily able to run five miles on the open road.
There are advantages and disadvantages to both treadmill running and road running. Many beginning runners question the effectiveness of tread running opposed to road running. Each have unique benefits that contribute to a runners training depending on the goal to be reached. For fitness alone, exclusive treadmill running suffices. However for a runner whose goal is a race on the open road, a balance between indoors and outdoors is crucial for success.