Understanding High Intensity Interval Training (HIIT)

Fat loss is one of the major reasons that individuals take up exercise. However, traditional training methods have relied on “steady state” aerobic type exercise to no avail. Current research indicates that High Intensity Interval Training (HIIT) may be more advantageous in achieving health benefits. University of NSW Associate Professor Stephen Boutcher has highlighted the fat loss benefits of High Intensity Intermittent Exercise (HIIE) in a highly regarded research article calledHigh-Intensity Intermittent Exercise and Fat Loss published in 2011.

The excitement over High Intensity Intermittent Training stems from the economical and time saving promise of the exercise protocol. Given how time poor we all are these days, very few people have the time or energy to incorporate several gruelling hours on the treadmill without seeing worthwhile results. HIIE provides a more efficient option whereby each minute of exercise is maximally contributing to fat loss.

What is High Intensity Interval Training?

In general, High Intensity Intermittent Exercise (HIIE) is synonymous with High Intensity Interval Training (HIIT) and involves short bouts of near-maximal exertion, followed by equal or slightly longer bouts of low intensity or rest.

For example, in A/Professor Boutcher’s research, they explored the use of “life sprints” which involved 8 seconds of maximal sprint on a stationary bike followed by 12 seconds of slow cycling. The two intensities were alternated continuously for 20 minutes.

At Activate Clinic, we use High Intensity Interval Training to maximise the benefits of exercise relative to invested time. We combine a variety of exercises using primarily a resistance (weights) based program where we alternate a work set with a brief rest.

How Does Interval or Intermittent Training Improve Results?

Shorter intervals of high intensity result in a large aerobic and metabolic response from the body. During the low intensity interval, the body maintains its metabolic response but without the individual continuing to stress the body physically. This allows, for example, a 20 minute interval training session to generate a response similar to going 20 minutes at a high intensity but with only 10 (or so) minutes of actual exertion.

The rest periods allow for the individual to recover and not feel as exhausted as they would if they were going flat out for the entire duration.

Boutcher’s research has reviewed several studies that have outlined the positive impact of High Intensity Interval Training on physical response:

  • Improved Fat Loss
  • Improved Hormonal Response (including catecholamines, cortisol, and growth hormones).
  • Improved Aerobic & Anaerobic Fitness
  • Decreased Fasting Insulin & Insulin Resistance
  • Improved Muscle Strength & Activation

What’s not to love about those adaptations!

How You Can Implement Interval Training In Your Program

That’s the fun part – interval training is hugely customisable to fit a variety of different training modes. Here a few suggestions for common interval exercise strategies, but as always, consult an exercise professional to get the most out of your training.
  • Walking – Instead of going for a long casual stroll, alternate fast or power walking with leisurely strolling.
  • Running/Treadmill – Similarly, alternating between high intensity bouts (sprinting/uphill running) and lower intensity bouts (walking or resting).
  • Cycling – Whether on the road or on a stationary cycle, alternating between high intensity intervals and low intensity intervals can maximise physical response.
  • Resistance Training (Weights) – One of the best forms of High Intensity Interval Training – resistance training involving a high intensity set with a short rest can improve physical response over doing longer, low intensity sessions. [Our Supervised Gym incorporates HIIT training protocols]


Boutcher, S. (2011). High-Intensity Intermittent Exercise and Fat Loss. Journal Of Obesity, 2011, 1-10. http://dx.doi.org/10.1155/2011/868305

About The Author