Speaking of muscle growth, we can mean two phenomena – increase in the number of muscle fibers (hyperplasia) and enlargement of their size (hypertrophy). Until then, we can only rely on hypertrophy because hyperplasia does not have significant meaning in humans. There is no scientifically proven effectiveness of any training method, diet or supplement that would cause a significant increase in the number of muscle fibers in humans, although this phenomenon is quite common in other mammals. When it comes to hypertrophy, that is, the increase in the size of individual muscle fibers, it is responsible for increasing the volume of muscles and, consequently, strength.
When we start strength training, muscle growth does not happen immediately – the body first has to go through the period of adaptation or adaptation to new loads, and not only in relation to the muscles but also in relation to the central nervous system. Changes in the functioning of the nervous system mainly consist in increasing the frequency of signals sent from the brain to muscles during exercise and improving the synchronization of the work of individual muscles and their groups. Colloquially we perceive this as a process of “learning to do exercises, but actually in the first month at the gym there are many deep changes in us, mainly in the sphere of the nervous system and not the muscles themselves. This phenomenon is also the reason for the fact that in the first month of exercise, any muscle growth can be observed very rarely. The process of nervous system adaptation, depending on the type and intensity of training, usually lasts from 4 to 8 weeks. In this period, the person starting to exercise can mainly observe an increase in strength expressed by the ability to lift higher weights, which indicates both the adaptation of the nervous system and learning the correct technique for doing exercises.
After the initial adaptation period, we begin to observe the first signs of muscle growth. They usually appear about 4-5 weeks of exercise. In fact, what is the main factor stimulating muscles to grow is not known until the end, but several key factors have been identified without which muscle growth is impossible. These are
– metabolic work
– eccentric movement
– sufficient recovery time
– availability of building proteins
The load used in the exercises is an extremely important factor in the growth or lack of muscles. The minimum load that is able to stimulate the muscles to grow is about 60% of the maximum weight that we can only raise once in a given exercise. The optimum load range for muscle growth is from 60 to 85% of the maximum weight, which usually corresponds to the performance of 6 to 20 repetitions with a given weight in a given exercise performed for muscle fall (ie until we are no longer able to do one more repeats without rest). However, the load itself is not enough to stimulate the muscles to grow – they have to perform specific metabolic work. As a result of subjecting the muscles to load over time, the biochemical changes are intensified, the most well-known effect of which is the formation of lactic acid. For such changes to occur, the minimum duration of the exercise (one series) should be 20 seconds, optimally from 20 to a maximum of 60 seconds. Although it is not very important for beginners, it may be worth knowing that the series lasting from 5 to 20 seconds (1-5 repetitions, assuming that the repetition lasts 3-5 seconds), mainly affect the improvement of strength by improving the work of the central nervous system, series of 20-45 seconds (5-15 repetitions) stimulate mainly muscle growth by affecting muscle type IIa and IIb, while the 45-60 second series mainly build endurance influencing glycogen capacity increase, number of mitochondria in muscle cells and increase of sarcoplasm volume) .
It is not without significance what is happening during the series, or more precisely what kind of movement (work) they perform muscles. When we lift a weight, the muscles shrink, overcoming the resistance of the load and the force of gravity – this movement is called concentric. When we leave the weight in a controlled manner (i.e. such that it falls slower than if it fell under the influence of gravity), the muscles prolong and this movement is called eccentric. Eccentric movement is the key movement for muscle growth because it is in it are involved type II muscle fibers, which is precisely the ones on which we grow mainly because they are growing the fastest. What’s more, when lowering the weight, much less muscle fiber participates in such work, so the load per one fiber is higher, which can also be the reason that muscles grow better from “lowering than” than lifting. It is not without significance that in most exercises we are able to lower loads in a controlled way by 30-40% more than we can lift (absolutely not recommended for beginners) and that eccentric movements stimulate protein synthesis more than concentric movements. And finally, one more important thing – when leaving the weight, most of the micro-damage and lactic acid that stimulates the muscles to grow. From the information we have about the eccentric movement, one conclusion is coming – lowering the weight should always last a bit longer than its lifting and always take place in a controlled manner.
It is justifiable to say that muscles grow between workouts – indeed, training provides only a stimulus for growth that occurs in the regeneration trance. Depending on the degree of damage to the muscle fibers and the body’s effectiveness in removing lactic acid, muscles require between 4 and 7 days to break between workouts. We should also keep this gap by training individual muscle groups for weight gain.
The key element deciding on stimulating the muscles to grow is the progressive increase of the loads from the training to the training. Regardless of the training plan used, it will not bring long-term effects if we do not increase the weight weights. Interestingly, the slower we add weight, the longer we avoid stagnation, so especially for beginners it is recommended to increase the load by 0.5-2 kg. It should be remembered that the load is increased only when with the reserve of strength we are able to perform the assumed number of repetitions maintaining impeccable technique of performing the exercise. In this situation, we slightly increase the load on the next workout. If we increase the load considerably, the number of repetitions should be reduced accordingly.
In addition to the issues arising from the training should be remembered that muscle growth occurs only when the availability (excess) of calories and proteins. It is served by a well-chosen diet whose laying has been discussed many times in other articles.
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