Are hours of cardio training necessary for fat burning?
Cardio - you either love it or hate it. For most bodybuilders or fitness professionals, cardio is an essential part of a fat burning training effort, especially in preparation for competition stages. Cardio training can look like anything - some do 20 minutes of cardio twice a week, others do cardio twice a day, there are even those who spend 45 minutes a day 45 minutes a day on a treadmill or bike.
Many coaches or online sports forums warn against the "catabolic effect" of excessive length of cardio exercise. Here the question arises: But when does the length of cardio exercise become "exaggerated"? If we look at this question from a hormonal point of view, it looks like about 60 minutes is the time when cortisol levels start to significantly rise. Cortisol is a steroid hormone that, among other effects, is responsible for catabolizing (breaking down) muscle mass. Cortisol also promotes the secretion of myostatin, which actively stops muscle growth. However, there is also the often-overlooked effect of cortisol, which we can use to our advantage - cortisol helps to mobilize fats and provides us with these activated fats as a source of energy. However, muscle catabolism caused by elevated cortisol can be suppressed by taking branched-chain amino acids BCAAs during / before cardio exercise. These amino acids help to suppress the breakdown of muscle mass, but at the same time do not block the mobilization of fats.
I'm sure you can think of an equation - the longer the cardio - the more calories burned - the greater the loss of subcutaneous fat. However, this equation has a catch - there is another unstated parameter - the compensatory effect that occurs after the end of the training unit. If the body feels that it has been depleted, too much energy will start triggering automatic processes that lead to an increase in appetite - as a means of recompensing for lost calories (Note: this is why cardio exercise can be beneficial for people who have an appetite problem).
That’s the way the famous JOJO effect works.
However, the idea that it is enough to follow the equation - "I consume fewer calories than I burn" is not utterly complete. An especially important question is: "What did I lose weight from?" If an athlete loses lean muscle mass during cardio, he or she is all the more likely to regain lost fat. The proportion of pure muscle mass is a particularly important parameter of basal metabolism. If the athlete loses more lean muscle mass, the value of basal metabolism will be reduced. This means that the body suddenly needs LESS calories to regain weight - but most often in the form of fat. The combination of the compensatory effect and the slowing down of basal metabolism is thus the answer to the question of why it is so easy to regain so hard to break down fat after the end of the diet.
But what about strength training? Strength workout, thanks to the building of lean muscle mass, helps to boost the value of basal metabolism, which facilitates fat burning for the athlete. There are several studies that without adequate strength training it is almost unfeasible to keep the percentage of subcutaneous fat low for a long time!
does that mean I should omit cardio COMPLETELY?
NO! Cardio exercise not only keeps the cardiovascular system in good shape, but also helps with fat burning!
how much cardio needs to be PRACTISED for the most effective fat burning?
A 2012 study (the source below) tested 64 slightly overweight people aged 20-40 who were randomly divided into the two groups tested. One group completed 30 minutes of cardio, three times a week, while the other group completed 60 minutes of cardio, three times a week. The study lasted 13 weeks and returned a surprising result. Although the 60-minute group burned twice as much energy as the 30-minute group, both groups lost the same amount of body fat (14%)! Intriguingly, however, the exercisers in the 60-minute group developed a more intense compensatory effect in the form of a significantly increased appetite during rest!
From these findings, we can therefore recommend a combination of strength training and cardio exercise lasting 30-45 minutes for the most effective subcutaneous fat burning.
As a great alternative for lengthy cardio exercises is HIIT training, which we will talk about in more detail in the next article.
Have good sport! :)
Study: Rosenkilde, M, et al. Body fat loss and compensatory mechanisms in response to different doses of aerobic exercise--a randomized, controlled trial in overweight, sedentary males. Am J Physiol Regul Integr Comp Physiol 2012;303;R573=R579.
Author of the article: Vladimír Roško - The cult of the body from my point of view
