HIIT is an acronym for high-intensity interval training. HIIT is a form of cardiovascular exercise. In HIIT training you alternate periods of short intense anaerobic exercise with less-intense recovery periods. Usual HIIT sessions may vary from 4–30 minutes. These short, intense workouts provide improved athletic capacity and condition, improved glucose metabolism, and improved fat burning.



Studies have shown that HIIT training helps to stimulate the sympathetic nervous system to burn more fat as compared to steady-state exercise and in less time. Not only does HIIT optimize fat burning while exercising, but it also continues burning fat long after the exercise session is over. This is because of something called EPOC (excess post-exercise oxygen consumption). When your EPOC is high your metabolism is revved up and you have an increased secretion of growth hormone and noradrenaline. These hormones help break down stores of fat and increase their use as a fuel source. The body uses a ton of calories to return the body to its resting state. Some of the things the body needs to increase the burning of calories for is replenishing depleted energy reserves, repairing cellular damage, clearing metabolic byproducts and facilitating tissue growth. This effect lasts as long as 36 hours after exercise, burning as many as 150 calories a day beyond resting levels.


Long steady state cardio has been known as the best way to burn fat because it’s been said that fatty acid utilization usually occurs after 30 min. HIIT is kind of the exact opposite with short intense workouts, but has been shown to burn fat more effectively. There may be a number of factors that contribute to this, including an increase in resting metabolic rate. HIIT also significantly lowers insulin resistance and causes skeletal muscle adaptations that result in enhanced skeletal muscle fat oxidation and improved glucose tolerance.



There is no specific formula to HIIT. Depending on how fit someone is the moderate-level intensity can be a slow walk or for a more experienced person it could be a jog. A common formula involves a 2:1 ratio of work to recovery periods, for example, 30 seconds of hard sprinting alternated with 15 seconds of jogging or walking. Make sure the work period whether it be 20/30/45 seconds, , make sure it’s an all out effort. At first you may have to do a 1:1 ratio meaning 30 seconds of work and 30 seconds of recovery, but really work towards making it a 2:1 ratio for the best benefits.

I would not choose to do ONLY HIIT as my cardio program but alternating between HIIT and long duration steady state cardio. They each benefit you in different ways. I’ll get into the benefits of long steady state cardio in a separate post.