There’s nothing wrong with opting for a treadmill, especially if the weather’s nasty. But treadmill and road running each shape your running style differently. Running on a treadmill can affect your foot strikes, for example, in good and bad ways. In general, to prevent bad running habits, you should ask an experienced running coach to diagnose flaws in your running form, both indoors and outdoors.
When you run, you should strike the ground flat-footed, with your foot underneath your hips. If you strike with your heel first -- called overstriding -- you decrease the power and efficiency of the stroke. On a treadmill, overstriding becomes more likely as you tire, according to Jay Dicharry of the University of Virginia, Charlottesville, as quoted in a January 2007 article in “Runner’s World.” Trying to match the pace set by the machine can cause you to neglect proper running form. When you're running outdoors, in contrast, maintaining proper form just involves slowing down, even for a few seconds.
If the belt on your treadmill is narrow, you must avoid letting your feet land too far to either side -- unless you like tumbling to the ground in front of everyone in the gym. This problem is more likely to occur if you have a wide running stride, according to the book “The Runner's Book of Training Secrets” by Ken Sparks and Dave Kuehls. Also, if you continually adjust your foot strikes to compensate for a narrow treadmill, you might develop an unnatural or inefficient running stance.
Reduced Foot Stress
The good thing about running on a cushioned surface is it offers you some relief from running on hard concrete or pavement. The shock waves that result from repeated foot strikes on hard surfaces can cause joint problems and stress fractures, especially if you don’t see a doctor at the first signs of pain. The relatively springy surface of a treadmill fosters less-intensive foot strikes, relieving some of the lower-body stress runners often suffer.
A treadmill’s moving belt pulls your foot back slightly with each strike. In contrast, when running outdoors, your leg muscles do all of the pulling back. As a result, running on a treadmill can condition your body to get used to faster leg movements, leading to faster leg turnover and improved cadence when you return to road running, according to the book “Long May You Run: All Things Running” by Chris Cooper.
Stan Mack is a business writer specializing in finance, business ethics and human resources. His work has appeared in the online editions of the "Houston Chronicle" and "USA Today," among other outlets. Mack studied philosophy and economics at the University of Memphis.