Many people believe that muscle pain is a necessary condition for their growth. The scheme is simple: muscle fibers are damaged, the body accelerates protein synthesis to repair them, and then builds a little more to protect itself from further stress.
If this theory is correct, after each workout a person should feel pain, otherwise the load was not enough and it needs to be increased. In fact, this approach can backfire for several reasons:
Delayed muscle soreness reduces their ability to produce force, so you can do less in your next workout.
Constant pain is tiring and reduces motivation to exercise.
Inadequate load can lead to overtraining and hit the indicators hard.
New studies are gradually appearing that prove the absence of a connection between the repair of muscles after damage and their further growth. And although science does not yet give a clear answer to this question, there are reasons not to consider pain the only indicator of a good workout.
Why muscles grow and how they are damaged
Repetitive muscle contractions during exercise cause mechanical stress. It starts the process of adaptation of the body to the load - it gives a signal for the addition of fibers. The more tension managed to create, the more stimulus for growth the body will have.
But if the load is too high or the muscles are not ready for it, their fibers are damaged, inflammation and swelling increase, the tissues squeeze the receptors in the muscles and you feel pain.
Thus, mechanical tension is responsible for both muscle growth and muscle damage.
However, these are two different processes that can occur both simultaneously and separately from each other.
Why muscle recovery and muscle building are not the same thing
There are several proofs of this theory, both scientific and empirical.
Increased protein turnover after damage does not cause hypertrophy
After injuries, protein turnover is stimulated in humans: both production and breakdown. It is believed to help build muscle fibers. However, there is also a reverse view: protein turnover increases in order to increase their volume and repair damage.
Due to increased decay, the body cleans the damaged parts of muscle fibers, and due to synthesis, restores them or grows them anew.
The body simply fixes what was broken, and this does not affect the emergence of new muscle fibers.
This assumption was confirmed in the study. Scientists found out that increased protein turnover in the early stages of strength training, when muscle damage is most significant, does not lead to hypertrophy of their fibers.
Eccentric exercises may not cause pain
Eccentric exercises are those in which the muscles are stretched under load; concentric - when shortened. For example, if you swing biceps with dumbbells, then the lifting of the arms is a concentric phase, and the lowering is eccentric.
Some studies show that eccentric training causes greater muscle growth than concentric training. At the same time, they create a strong delayed pain in the muscles.
However, eccentric training can cause pain.
This was confirmed by a study with two groups of participants. One of them exercised for three weeks on an eccentric ergometer for 5 minutes, and then began an eight-week program of more serious training for 20 minutes.
The second group immediately started the main loads, without preliminary training. And as a result, people in it experienced muscle pain, but not in the first one. At the same time, everyone built up muscles and strength equally.
Activation of progenitor cells does not increase the number of nuclei in muscles.
After damage in the muscles, the activation of progenitor cells increases. It is assumed that this leads to the creation of new nuclei in muscle cells and, as a result, the appearance of new fibers.
However, the study refuted this dependence. It turned out that at the beginning of the strength program, when the muscle damage is the most severe, the number of nuclei does not increase, despite the activation of progenitor cells.
Not all muscle damage coincides with growth
Since growth from mechanical stress and pain from this stress occur at the same time, it is difficult to separate them from each other.
To do this, scientists came up with the idea of damaging the muscles without mechanical stress and seeing how this would affect growth. The results confirmed: despite the injury, no muscle growth occurred without load.
Some muscle groups do not hurt, but grow
For example, the deltoid muscles that cover the shoulder joint or the muscles of the forearm rarely hurt after training, even in beginners. However, they still increase in size under the corresponding load.
Muscles hurt more often in those who exercise irregularly
At the same time, the results in strength indicators and muscle building are much better in those who perform strength exercises regularly.
Do not judge the quality of training by the amount of pain. If you don't have any pain, it doesn't mean that you didn't train well and the results will stand still. It is better to focus on volume and weight growth in strength exercises.