Why run at all? 35 minutes of brisk walking is more likely to get someone off the couch. The dirty secret is, no one can make any money off you, once you buy your sturdy shoes, or non slip boots for winter. Add poles and a hill if you want more cardio and upper body stuff. Wear layers, as I plan to today, to face the minus 20 weather.  Problem is, anyone with functional feet can do it, so it lacks cachet.  It's so...pedestrian.