We all dread cardio, but it's an important training component that helps to create a needed calorie deficit to speed up the metabolism. But which form of cardio is best: low-intensity steady state (LISS) or high-intensity interval training (HIIT)? While HIIT is finally gaining momentum as the preferred method of cardio, both have their place in a fat-burning program.
Low-intensity steady-state cardio allows for a longer fat-burning session, but HIIT training cranks up your metabolic rate and increases fatty oxidation rates for hours post-workout.
Instead of choosing one or the other as your “exclusive” form of cardio, try doing a few sets of HIIT, then moving into steady-state training. This will allow you to reap all the benefits of both, all in one workout. You'll get your interval work while your energy stores are high, and the steady state cardio will burn even more fat than usual because the intervals will have led to glycogen depletion.
Another option is to do LISS while fasting before breakfast for a minimum of 40 minutes, and to perform HIIT cardio in a separate session. A recent study from the UK published in the British Journal of Nutrition found that when fasted subjects did morning cardio, they burned 20 percent more fat than when they had a meal before the cardio.