All I did in the past was run for half an hour at a time on the same zero percent incline, at a relatively fast but consistent pace. Now, I've found success in using running apps to help me get creative with my workouts. One, Apptiv ($15 per month), features guided audio runs with trainers who break down what you need to do and add in plenty of motivating one-liners, too. Peloton's digital app ($20 per month) lets you follow along to live or on-demand videos filmed in the Peloton Tread Studio, and its this app that taught me that you can hike up a 15 percent incline for 20 minutes and get an amazing sweat out of it. Plus, it legitimately has "fun runs" to choose from. Those are two that have worked for me; here's more.