Basic cardio isn't enough. In order to target the waistline, interval training is a must. It involves mixing up your regular pace with fast-paced bursts. Here's a 40-minute workout perfect for newbies that incorporates two-minute sprints with one-minute walking recovery intervals. Running isn't the only way to do intervals. They can also be done when biking, swimming, jumping rope, or even dancing. Doing hill repeats is also a form of interval training that as a bonus will also tone your tush.