The most effective training you can do for fat loss is intervals.
The main reason is that intervals are more metabolically demanding, which means you to burn more fat and calories in the 24 hours after you finish exercising, when the muscles are busy repairing, recovering and replenishing themselves.
As many of you know, the term “intervals” refers to exercise where the intensity is varied rather than steady-state where the intensity doesn’t change much. Intervals use all-out sprints sandwiched between easier paced recovery cardio. An example might be sprinting for 30 seconds and then recovering for a minute at a slower pace. You would then repeat this sequence for a number of repetitions or a specified time.
I just read a new study from Australia that compared intervals to steady-state aerobics for fat loss. The researchers, Trapp & Boutcher, put 45 overweight women through a 15 week study where one group was a control, one group did intervals (20 minutes of eight seconds of sprinting on a bike followed by 12 seconds of recovery at a slower pace), and one group did 40 minutes of steady-state aerobics.
The interval group lost an average of 2.5kg in the 15 weeks and the steady-state group gained .5kg. In other words, the interval group lost three times as much fat doing half as much exercise.
I think these results speak for themselves!