Which is More Effective?According to an article published in Fitness Prescription magazine, running outdoors has the edge since it burns around five percent more calories than running on a treadmill. This is due to the lack of wind resistance indoors and the fact that the moving treadmill belt adds momentum. Running outdoors is also more motivating for some people than running indoors on a treadmill – particularly when the weather is nice outside.Treadmill vs. Outside Running: The Downsides of Running OutdoorsRunning outdoors has some disadvantages other than the weather. Running on hard pavement such as sidewalks and roads increases the risk of stress fractures and overuse injuries – particularly if proper shoes aren’t worn. Injuries sustained from running outdoors can mean weeks spent on the sidelines which requires starting over in terms of fitness. Plus, anyone who has orthopedic issues is better off running on a treadmill as opposed to outdoors.Interval Treadmill Running Despite the fact that running outdoors burns more calories, there are ways to make treadmill running just as effective. Try interval treadmill running to burn more calories. This involves running at a slow pace for two minutes followed by one minute of an all out effort to maximize oxygen consumption. Alternate back and forth for twenty minutes. This is a tough workout that gets fast results. You can also make treadmill running more effective by continuously varying the gradient to simulate the varying terrain you deal with when running outdoors. Resist the temptation to keep the incline low and the pace steady. Treadmill running should be challenging too.Treadmill vs. Outside Running: The Bottom Line?Running outdoors may be a more effective way to burn calories, but treadmill running can be as challenging as you make it. Challenge yourself by upping the speed and gradient and you’ll get an effective workout on those snowy days when running outdoors isn’t possible.