One of the fastest ways to lose belly fat and improve your aerobic capacity is utilizing the Fartlek system of training. We've all run outside or on the treadmill at the same pace over and over for a long period of time. While this burns calories it also bores us to tears. Fartlek training allows you to run at differing tempos, recovering and upping the intensity again. It's a time saver and anyone can train using this system. You should always do a 5 minute warm-up before running at higher speeds as well as a 5 minute cool down.