In the past we have been bombarded with information from books, magazines, television shows and fitness experts about the right way to burn fat; 65% of your maximum heart rate for more than 30 minutes, three or more times a week. It’s true that this WILL burn fat. However, this classical view of training is not the only (or even the most effective) way to burn fat through exercise. Enter High Intensity Interval Training (HIIT).

HIIT is a form of training traditionally used by athletes to increase VO2 Max, but it’s fat burning capabilities and short sessions make it a perfect candidate for ANYONE to try. How does it work? HIIT is a form of Interval Training so it involves breaking your workout into 2 types of intervals, typically a high intensity interval, and a rest or low intensity interval. These two intervals last 10-40 seconds each and are repeated for a maximum of 20 minutes.

Interval One - High Intensity Interval, or the high intensity interval consists of the exerciser reaching their maximum heart rate and keeping it there for the duration of the interval. Maximum Heart Rate (MHR) Calculator.

Interval Two - Rest Interval, or rest/low intensity consists of the exerciser bringing their heart rate back down to around 60% of MHR in preparation to repeat Interval One. While it is the ‘rest’ interval, it’s best not to fully stop exercise during this interval but rather slowing to a fast walk.

Unlike traditional approaches to burning fat which focus on burning calories DURING exercise, the magic of HIIT occurs in the 24 hours after the workout by spiking your metabolism. HIIT boosts your metabolic rate and burns through those burgers while you sleep - not while your on the treadmill.

You can do a HIIT routine almost anywhere using almost anything. In my experience the most popular way to HIIT is running on a track, stationary cycling and skipping. Anything is suitable as long as you are in an environment where it is safe to exert yourself to maximum heart rate.

HIIT is not the latest get slim quick scheme, it’s not the Atkins diet of the training world, and it most definitely IS NOT easy. HIIT sessions are limited to 20 minutes due to the fact that it’s really not possible to go for any longer, due to intensity of the workout. If you find you can take your HIIT sessions longer than 20 minutes than your intensity is too low.

Let’s take a look at some typical HIIT routine:

Warm Up

15 seconds high intensity (sprint)
25 seconds low intensity (walk/jog)

Cool Down and Stretch

This routine is very common, and would be classified as HIIT because it is very possible to get your heart rate to maximum within a few minutes of intense exercise. This routine is suitable for more advanced trainers with a high level of fitness.

Warming up before starting your HIIT routine (including stretching) is extremely important in reducing the risk of injury. HIIT is intense, it pushes your body to the limit and if you don’t prepare yourself for that your going to get injured and lose motivation. It is recommended that at the bare minimum, your warm up should consist of light jogging for 5 minutes, and stretching for an additional 5.

The cool down occurs immediately after your HIIT routine and is as important as the warm up. The cool down helps flush lactic acid from the muscles and reduces the effect of DOMS (Delayed Onset Muscle Soreness). By making sure you cool down after your HIIT session you will increase your chances of making it to work the next day. The cool down should also consists of light jogging and stretching.