Treadmill vs Outdoors...

Have you ever wondered which is better? Running outdoors or on a treadmill?

Running is one of the best exercises for promoting weight loss. Most runners have a definite preference for exercising either outdoors or on a treadmill. Outdoor running burns about 5% more calories at any given speed than treadmill running. Running outdoors subjects runners to wind resistance and they receive no assistance from the treadmill belt. Outdoors, the runner must push against solid ground to move forward. On a treadmill, the belt moves continuously, so the runner doesn't have to push as hard against the surface. However, outdoor runners have a higher rate of musculoskeletal injury than treadmill runners and have a 50% greater risk of stress fractures. Running outdoors burns more calories than on a treadmill, but increases the risk of injury.
(New York Times, May 6, 2008)