Poor air quality can make it hazardous to run outside.
So how does running on a treadmill stack up?
There are two fundamental differences when running on a treadmill compared to running outdoors.
1. The belt is moving under you
2. There is no wind resistance for your body to work against.
These two differences theoretically should make it easier to run faster and/or further on a treadmill for the same amount of effort.
Research has shown that setting the treadmill on a 1% gradient offsets these two advantages and makes treadmill running similar to outdoor running in terms of the amount of effort required.
Our friends from The Body Mechanics teach us how to keep correct form.