One of the great myths that circulate through all gym training rooms, even occasionally endorsed by coaches with a certain prestige, and that as a personal trainer I have to constantly deny, is the alleged negative relationship between aerobic training and strength development And muscle mass. According to those who defend this theory, if you perform aerobic training, either in the form of work at moderate intensity and constant, or HIIT (High Intensity Interval Training), would reduce the development of muscle strength and mass, if performed in parallel training for this purpose. For this reason so many regulars to the training rooms that try to obtain these results leave this type of training, at least until the summer begins to approach, for fear that it hinders the desired evolution.
But beyond myth and tradition, what do we really know about this alleged negative relationship between aerobic exercise and muscle development?
BACKGROUND
Those who have defended this supposed relationship knowingly, and not because someone bigger than himself, were based on a molecular mechanism observed in vitro and in rodents, where aerobic exercise increased the activity / presence of the enzyme AMPK, something that occurs when our energy reserves decrease, which supposedly would nullify the activity of mTOR (target of rapamycin in mammalian cells), a key protein in muscle development. Today has not been able to show that this process occurs in living humans, beyond what was observed inside a test tube.
MUSCULAR DEVELOPMENT (HYPERTROPHY)
Several studies have been carried out where the same protocol of training for the development of muscular mass was added or not, aerobic training, either at the end of the session, or on different days of the week, with opposite results to the expected, since in the worst muscle development was the same but, surprisingly, in other cases was even higher.
DEVELOPMENT OF FORCE
In the different studies in which a greater development of muscle mass was obtained in those protocols where both strength and hypertrophy and aerobic training were performed, there was, curiously, no improvement in strength in this group compared to those who did not perform the aerobic part . One possible explanation would be that the extra muscle mass obtained in the group that also performed aerobic exercise was not due to an increase in tissue with contractile capacity, possibly water. Especially representative is another study where, despite having obtained further development of muscle mass the group added aerobic exercise (6% vs. 3%), the concentric force decreased versus the group did not make this Part of the training (5% vs. 10%).
CONCLUSION
If your goal is to maximize gains in strength and / or muscle mass, do not be afraid of aerobic exercise, whether at moderate and steady intensity or HIIT. Say what they say those who, by their appearance, seem to know something of what they say, scientific evidence are what they are, despite who weighs. If you notice that the weight gain suffers, think that having extra energy consumption is possible that you are getting less fat, which affects the figure we observe on the scale, but not the muscle mass gained.