This is a Tabata workout, which is a form of HIIT, and it's proven to help diminish belly fat better than steady-state cardio. Each four-minute section of this workout involves eight rounds of 20 seconds on and 10 seconds off. What makes this workout so intense is that it's long: 45 minutes total!
Equipment needed: jump rope (or just pretend!) and a set of medium-weight dumbbells