Ready, reset, go: our Flat-Belly Challenge has 21 days of belly-blasting workouts, tips, and recipes to help you start a new season on a fresh note. Today, day one is all about belly-fat-fighting intervals and a debloating smoothie made with pineapple, kale, and blueberries.
Fire-It-Up Interval Workout
Let's begin with the fat-blasting workout. We've created three versions of this treadmill run, along with a printable version of all three levels. If you're new to running, try the Walk/Run plan farther down the page. And if you want to increase the speed, use the Run Faster program.