HIIT: What is it and what are its benefits?
Article proofread on: 16/2/2018
High-Intensity Interval Training (HIIT) is an acronym that is quickly becoming a prevailing expression within the world of sports. Essentially, this is a training method that consists of performing compound exercises (multi-joint movements that work several muscles or muscle groups at a time), in short sets, at a high-intensity level and with short recovery times between sets.
Advocates of High-Intensity Interval Training claim this technique gathers the best of two worlds that, traditionally, are not compatible: retaining/gaining lean tissue while, simultaneously, losing fat. Allegedly, this type of workout can also accomplish another important feat, which is to burn more calories and in less time than with conventional cardiovascular and resistance training. According to recent research, that measured and analysed several relevant body indexes, this allegation is substantiated by the metabolic and hormonal response the body gives this high-intensity effort.
The use of traditional low-intensity cardiovascular training to burn body fat relies on the assumption that this type of routine leads to a significantly high utilization of body fat to fuel the exercise. However, data registered in equipment that measures cardiovascular performance reveals that low-intensity exercise, performed at about 60% of maximum heart rate, is actually not the best strategy to burn fat.
In reality, a fast-paced walk or a light jog do manage to burn more fat relative to glycogen. However, relative body fat burn and total fat burn are two different things and, for someone who exercises looking to lose fat, total fat burn is the index that really counts. At higher heart rates, total body fat burnt is significantly higher than what is achieved with long, low-intensity training routines.
Furthermore, High-Intensity Interval Training increases stamina, allowing athletes to exercise at very high intensities for a much longer period of time than steady state, burning more fat in the process.
Lastly, High-Intensity Interval Training produces an extremely interesting secondary effect, called EPOC (Excess-Post Exercise Oxygen Consumption). The EPOC effect, generated by the metabolic acceleration created by HIIT, prompts the body into continuously burning additional calories over a period of up to 24 hours after exercise. Unlike with HIIT, the EPOC effect produced by low-intensity cardiovascular exercise is minimal, burning very few calories after exercise.
Concerning the anabolic effect generated by HIIT, there is solid data demonstrating its efficacy. Firstly, doing HIIT has been shown to increase lactate threshold, which means your ability to handle increased lactic acid buildup in your muscles increases. By increasing lactate threshold, athletes are able to train harder and for longer periods of time, promoting muscle development.
HIIT can also improve insulin sensitivity. This hormone optimization effect leads the body into quickly using the available glucose as an energy source, instead of storing it the fatty tissue. Optimizing insulin sensitivity also improves several functions associated to muscle recovery and development.
Data gathered with specific research also enabled to determine HIIT combined with consuming slightly more calories than your normal caloric expenditure, creates an anabolic effect that helps you put on muscle. The opposite occurs with steady state cardio, that actually becomes catabolic in long training sessions, since it prompts the body into breaking down muscle tissue, to use as energy.
The ideal training plan is composed by multiple training methods and techniques, that are able to constantly surprise the body, forcing it to adapt and respond with some level of muscle transformation.
Recent findings on the effects of HIIT have allowed us to determine it is a very valuable and effective training method for anyone looking to lose weight, without compromising muscle volume. Nonetheless, traditional cardio training does have its merits as well and, in the interest of promoting variety in training, it should be incorporated into any athlete’s workout routine.
To get the best possible results, be sure to include both these training methods in your exercise program, to constantly stimulate your muscles, thus promoting evolution.