one muscle group that should be recognized as optimal in the training mode we are considering. But a given number of repetitions is optimal for maximum destruction of myofibrillar proteins, but is maximum destruction optimal for achieving maximum muscle over-recovery during rest?

The law of restoration of energy reserves states that the greater the energy consumption during muscle work, the more intense the recovery processes and the greater the excess of the initial level of energy resources in the supercompensation phase. However, with excessively intensive work associated with a significant accumulation of metabolic products, the rate of recovery processes may decrease, and the supercompensation phase will be reached at a later date and less pronounced. Apparently, the processes of restoration of muscle protein structures also obey the same law. As I have already shown in the second part, excessive destruction makes recovery processes difficult and can even lead to a negative result. Therefore, it should be recognized that the number of microtraumas received during training should not be maximum, but optimal, sufficient to initiate recovery processes, but not too large to disrupt the recovery capabilities of the body. It is impossible to unambiguously indicate the number of approaches necessary to achieve the optimal number of microtraumas, since this number depends on the level of muscle training and the intensity of the load. So, even one intensive approach (hereinafter, we mean the intensity that allows you to perform the exercise within the required range of load duration) may be more effective than several less intense approaches, and several high-intensity approaches may be too much. destructive to the body.

There are two competing methodological approaches in adjusting the level of training load:

The first one is when the volume of the load to be performed is set in advance, for example, 5-6 approaches, but at a given intensity level and for a given duration of the approach (the weight of the projectile and the number of repetitions are known in advance), of course, the approaches are not performed to failure, but are interrupted when the given work is completed. As the fitness of the muscles increases, the intensity of the approaches (projectile weight) also increases, in this way a clear dosing of the load is carried out. The mistake, in this case, is not to regulate the load in advance, but seeks to perform all approaches to failure at the intensity limit, trying to squeeze the maximum out of the body.

The second approach is based on the exact opposite principle - the work uses the maximum intensity load that can be developed within the required range of duration, but the overall effect of training on the muscle is regulated by the number of repetitions of such a load (that is, the number of sets). In this case, the required number of approaches, as a rule, is less than in the first method. The achieved effect depends not only on the magnitude of the load, but also on the level of muscle training. So in untrained muscles, even one approach of far from extreme intensity causes severe destruction (remember, your feelings the next day after the first visit to the gym) and vice versa, in a trained muscle, even a lot of high-intensity approaches may not cause the desired effect.

As you remember, with rare workouts recommended by Mentzer, the energy potential of the muscles remains at a rather low level even during a long period of training, since the immediate training effect in the energy sphere does not turn into long-term adaptation due to a large break in training, which facilitates the impact of the load. on the muscle. In Mentzer's 'Supertraining', each workout is close to the "first" workout in terms of myofibrillar protein-destroying effect, which is why with this type of training, one single "failure" approach is sufficient.

What should be the number of repetitions in the exercise?
Another perennial question is what should be the number of repetitions in the exercise?

The determining factor is not the number of repetitions, but the time spent under load. The probability of occurrence of microtrauma increases significantly after a decrease in the concentration of creatine phosphate by half of the initial level, which in fast fibers occurs approximately at the 7th 10th second of the most intense work. At the same time, the probability of getting microtraumas is significantly reduced after reaching the maximum rate of ATP reproduction due to glycolysis and a decrease in ATPase activity of muscles due to the accumulation of acidic metabolic products, which is observed approximately 30–40 seconds after the start of work. Thus, to achieve the desired effect in fast fibers, the approach should last no less than 7 mi and no more than 40 ka seconds. So how long exactly should the load last. Интенсивная работа до отказа длительностью 7 секунд обеспечивает более высокую скорость расхода энергии, чем работа длительностью 40 секунд, но малая длительность такой работы не обеспечивает максимального воздействия on the muscle. On the other hand, work lasting 40 seconds lasts much longer and already after a significant decrease in the level of creatine phosphate, but the rate of energy consumption developed at the same time is much lower than in the first case. Apparently, the optimal duration of the load lies somewhere in the middle of the specified interval and is 20-30 seconds.

Why do different muscles, even in the same person, respond better to different numbers of repetitions? The fact is that different movements last different times. The greater the amplitude of movement, the longer the repetition lasts and the less they fit into the required time. So for 20-30 seconds of work in such movements as squats and deadlifts, you can do 6-8 repetitions, in pressing exercises and when working on biceps, triceps 8-10 repetitions, but already in exercises on the lower leg and forearm, the number of repetitions can be 10-15. As you can see, there is no fundamental difference in training the biceps, triceps femoris or lower leg, in all cases, despite the different number of repetitions, the load lasts approximately the same time.

But not rarely recommended, by some practitioners, the number of repetitions goes beyond the limits defined above and reaches 20-30 repetitions even in such exercises like squats and deadlifts. The fact is that muscles consist not only of fast, but also of slow fibers, and it is also useful to pay attention to training slow fibers. As I said earlier, the rate of ATP consumption in slow fibers is much lower than in fast fibers, so the contraction of slow fibers is energetically more stable. It is practically impossible to create a temporary deficit of ATP, necessary to obtain microfractures in slow fibers, in a period of 15-20 seconds. But, since the intensity of glycolysis in oxidative fibers is not high, and the maximum rate of ATP production by the oxidative pathway can be achieved only 60-120 seconds after the start of work, and muscle tension at a load of more than 30% of the maximum practically stops blood circulation (which makes it difficult to deliver oxygen and obtaining energy by oxidative means), then with extremely intensive work lasting 60-90 seconds, one can expect an ATP deficit and microruptures in slow fibers.

The contribution of slow fibers to overall muscle hypertrophy depends on their proportion in muscle composition. Apparently, claims that high repetitions work better on certain muscles come from people who have slow fibers predominate in these muscles. In general, it should be recognized that maximum muscle development can be achieved only by paying attention to fibers of all types.