High Intensity Interval Training (HIIT)

High Intensity Interval Training


High Intensity Interval Training (HIIT) has become a popular strategy for improving general fitness, reducing body fat and is currently being used by personal trainers and strength & conditioning coaches. This article will try and shed some light on the latest research on this training protocol and if it can benefit you.

A standard type of HIIT protocol involves alternating bouts of high and low intensity exercise with the theory being that you will increase the total amount of high intensity work performed in a session. The high intensity interval is performed above the lactate threshold and pushed close to fatigue, and this is then followed by the low intensity recovery period that facilitates the body to buffer and clear lactic acid from the blood, allowing the individual time to recover prior to performing the next high intensity interval (Schoenfeld et al, 2009).

Many traditional exercise programs focus on steady-state aerobic activity for fat loss and general fitness. Using the HIIT program has shown greater improvements in blood pressure and cardiac contractibility when compared to moderate aerobic activity. Schoenfeld (2009) has noted that HIIT has also been shown to be superior to steady-state training for people looking to reduce their body weight. While moderate steady-state aerobic training (“fat-burning zone”) results in an increased percentage of fat burned in a workout, the total caloric expenditure is substantially higher in the HIIT protocol and the resulting effects on fat loss are significant. These findings were substantiated by Koziris (2013), where it was shown the effectiveness of this type of interval training comes from the continued elevated metabolism during the hours after the session.

There are many variations of HIIT prescription, and 3-5 minutes work bouts with a work/rest ratio of 1:1 has been used for athletic groups (Reuter et al, 2008).  A study by Rozenek (2008) looked at favourable responses with the work/rest ratio at 1:2 and this enhanced both the aerobic and anaerobic energy system development.

Some points for you to consider in your decision to understand if this type of training may be beneficial for you. It is important that you have a reasonable level of cardiorespiratory fitness prior to adding HIIT into your routine. This type of program is extremely time-efficient, so it can assist in the time management of your training regime, which can consolidate exercise adherence. The HIIT protocol can also assist the athlete, as this training is a viable option to decrease body fat, improve overall fitness levels in reduced training time, allowing extra time to address skill development within your sport.

If you require further information, our trainers are available at the ANU Sport gym to discuss your individual training needs at any time.



The Fitness Services Team