The ACSM (American College Sport of Medicine) ranked high intensity interval training (HIIT) at number 1 of the training trends of this past 2014.
The truth is that today, the evolution of fitness has placed HIIT as a fashionable product, on which training methods such as Crossfit are based. Although it is nothing new, and interval training at high intensities has been used in athletes for more than a century, we must echo this trend and know what science gives us about it in order to apply it safely in ourselves themselves or in our clients or athletes.
What is HIIT
High intensity interval training (HIIT) is a training modality that consists of performing multiple sets of cardiovascular training at high intensity and with total or partial rest between sets.
HIIT has been used in athletes for more than a century, but it is science that has opened our eyes to the treasure that we had in our hands and that perhaps it is not being used as well as it should be.
That is why we must listen to what our researchers say about this field and not simply get carried away by the fashions that flood our rooms from one day to the next and in a massive way.
HIIT has great health benefits, preventing vascular disease, improving cardiovascular fitness or improving resting blood pressure (Burgomaster et al. 2008). It also improves insulin sensitivity in overweight subjects (Whyte et al. 2010; Hood et al. 2011), something very important to consider in the prevention and treatment of type 2 diabetes. The benefits in sports performance have also been demonstrated in numerous studies (Ziemann 2011; Gosselin 2012), also obtaining the extra benefit of saving time in each training being able to allocate it to less worked tasks, being also more pleasant to perform than the extensive continuous (Bartlett 2011). But it also carries risks that only the qualified coach knows how to handle, through a good dynamic warm-up and a tight individual
In this way, we cannot speak of the “HIIT Method”, as if it can be done with CrossFit or Pilates, but of one more training system, which generates stimuli with effects on the body that vary greatly depending on the stimulus. applied and the person who performs it (Borreani and Burdiel, 2014. “HIIT Guide”)
There are no miracle workouts, but good trainers who know how to combine scientifically proven training systems to achieve the best shape of a subject.
Talking about HIIT in just two pages is not easy. There are countless ways to do high intensity interval training. Of course, it must be a cardiovascular training, since the use of loads would no longer correspond to a HIIT itself. It can be running, even walking according to physical condition, by bicycle or any ergometer that mobilizes large muscle masses to provide a high oxygen consumption.
HIIT must attend to the duration of the intervals and the rest between them, as well as the number of final series. The intensity, as a key factor in the prescription of any exercise, will depend on the aforementioned aspects.
The work intervals must be greater than 90 seconds, being between 2-5 minutes the usual. It can be used for up to 8 minutes in trained people.
The intensities should be close to 90% of the maximum heart rate and the recovery between intervals can be passive or active, around 3 minutes. We will evolve and play with the execution time and its repetitions without having to reach exhaustion since the improvements already occur before.
Maintaining that intensity in such long intervals is not easy and therefore can be a good training volume reduction strategy for experienced athletes.
Talianan et al (2006) observed a higher consumption of fats to the detriment of carbohydrates in long intervals, which will allow athletes to have more tolerance to high intensity due to lower lactate peaks.
Short intervals will have a job of between 30 and 90 seconds. It is important to evolve in ratios of 1: 2, 1: 1, 2: 1 to ensure a correct adaptation, since the intensities of these intervals are still 90%, and we will only play with the densities, as we have just mentioned.
Gosselin (2012) studied the metabolic response of different types of short interval high intensity exercise with a maximum total duration of 10 minutes and continuous exercise of 20 minutes at 70% of the maximum heart rate. It was interesting to observe that the metabolic response was similar in all cases, the density being 3: 1, logically, the one with the highest