High Intensity Training (HIT)
General information on HIT for weight loss
For many years it has been believed that the best way to lose weight is to practise a lot of aerobic activity which, as we have said, allows you to selectively consume – with a certain training condition – the fatty acids of the adipose triglycerides.
It is not wrong, but neither is the only system. You can also lose weight by practicing high intensity workouts (HIT). Let’s see how and above all why.
Some studies show that high intensity training is no less effective than aerobic activity in promoting weight loss.
These insights refute what some (more and more), thanks to the experience in the field, a claim about slimming training; or that even HIT can effectively promote weight loss.
This contrasts with the trend of most professionals, who continue to promote aerobic activity as the most effective weight loss strategy.
First, to fully understand these studies, it is necessary to correctly define what high intensity training comprises.
HIT, IT and HIIT: what are they?
High intensity activity can develop in various ways, not necessarily starting from an aerobic metabolism base.
In practice, it is not necessary to run or swim or pedal or jump the rope until you go beyond the Anaerobic Threshold, but you can super-activate your energy metabolisms in order to immediately commit them to the maximum, for example by using muscle exercises.
In this case we consider such an exercise that brings the Heart Rate above the Anaerobic Threshold, since the studies examined use this parameter to define the training protocol itself as HIT.
If this work takes on the characteristics of an Interval Training (IT), it is commonly called High Intensity Interval Training (HIIT) or high intensity interval training.
Some find it superfluous to specify that it is an IT, since this activity is purely anaerobic and cannot be endured by the body for prolonged periods; it is therefore inevitable that it will be alternated with passive or active recoveries or in any case with activities of less intensity than the Anaerobic Threshold, to guarantee the continuity of the exercise itself.
The recovery interval, active or passive, is therefore a necessary condition; the difference lies in the fact that active recovery training represents a “variation of rhythm”, while passive recovery training constitutes a system of “repetitions” (REP or RIP).
Some athletes can continue the effort around the Anaerobic Threshold even for 40 minutes, which would make this training a “threshold” protocol.
Note: the following researches are all published in authoritative scientific journals and therefore have been conducted with absolute rigor.
Scientific Studies: HIT and Weight Loss
1st Study Tjnna and Co.
Tjnna and colleagues, who study metabolic syndrome, conducted this experiment to test various biochemical effects of two different physical activity protocols.
The first involves four periods of 4 minutes of activity at 90% of the maximum HR, interspersed with 3 minutes of recovery at an intensity of 70% HR max; the second protocol instead provides for a constant activity at 70% of the HR max, for a period that leads to the same calorie consumption of the first group.
These workouts are done on a treadmill 3 times a week for 16 weeks.
At the end of the study, various parameters are measured, including the FATP-1 and FAS enzymes, which in short are lipogenic enzymes present in the adipocytes responsible for the deposition of new adipose tissue.
The result is that the high intensity training protocol further reduces the presence of these enzymes in fat cells.
2nd Study Trapp and Co
Trapp and Co directly studied the effects on fat loss of two different training protocols.
The first, HIT, involved 8-second sprints followed by 12 seconds of recovery, for a maximum of 20 minutes, while the second involved pedalling at a constant speed, keeping the frequency close to 60% of the FC max, for a maximum of 40 minutes of training.
Note that also in this case the duration of the aerobic training was much longer in terms of time than the high intensity one.
Among the various results got with this study there is also the measurement of fat loss after 15 weeks of training: once again, the group trained with high intensity achieves a significantly greater fat loss than the other.
There are many other interesting data in this study, but in order not to become too dispersive I prefer not to talk about it.
3rd Study Tremblay and Co
This research dates back to 1997 and in this case 15 weeks of high intensity were compared with 20 weeks of aerobic activity.
Tremblay and colleagues studied two different high intensity interval protocols and compared them with a 30-45 minute workout in the aerobic range.
The results of this experiment are surprising, as the high intensity – in addition to increasing the production of various enzymes of the oxidative pathway to a greater extent than aerobic activity – has promoted a loss of fat nine times higher than that of aerobic training .
Does High Intensity Training Lose Weight?
Those listed are only part of the studies that show how HIT is as effective for weight loss as aerobic work.
There are also studies that show how weight training promotes weight loss effectively, but it is a topic in its own right. Other insights do not make the direct comparison between the two forms of training, but show unimaginable results on how high intensity makes you lose weight.
In conclusion, the proposed studies show that although from a purely biochemical point of view it is known that to consume fat for energy it is necessary to carry out aerobic activities, to activate the Krebs cycle and beta oxidation, there are other mechanisms. physiological able to promote lipolysis, therefore slimming.
The possible physiological and biochemical explanations are varied and some still to be fully demonstrated; however, the production of the particular enzymes mentioned above allows to plan some hypotheses.
Probably, the exclusive activation of aerobic systems promotes weight loss less effectively than a mixed training system would.