There's a reason runners refer to the treadmill as the "dreadmill." The exercise machine provides limited visual stimuli and is typically located in a gym or basement, which can be a stuffy, uninviting place to run. Clocking mile after mile in the same place, especially for a long run, can mean an hour or more of boredom.
There are, however, benefits to running on the treadmill, running coaches and exercise scientists say. The record-breaking temperatures and the poor air quality from the Canadian wildfires this year have made running outside risky or outright dangerous at times. Treadmills allow runners to keep training despite inclement or hot weather.