No excessive(!) caloric surplus is needed to build muscle
Many athletes have always believed that in a muscle building phase, you can only build muscle properly if you increase your body weight accordingly. Behind this is often the idea that there is a fundamental distinction between two phases: the bulking phase and the cutting phase. In the bulking phase you gain a lot of weight, and along the way some fat. Then, in the cutting phase, the muscles are being carved out.
However, studies have shown that, apart from a few exceptional athletes with a very fast metabolism, in all others the increase in weight with this high excess of calories is only about 20% in the form of muscle. The other 80% are mostly in the form of water and above all the unwanted fat. Now, in the subsequent cutting phase, the calories are reduced again to lose body fat. However, loss of body fat is associated with at least a slight loss of muscle mass in almost all cases (even with and without the use of “supplements”). This loss of muscles is greater the longer the diet lasts. When an athlete in such an extreme bulking phase gains a huge amount of weight, the loss of muscle mass in the following prolonged cutting phase afterwards will be much larger.
Especially for natural athletes a high body fat percentage brings another problem with it: the body’s own testosterone release decreases in people with a lot of body fat, which reduces the ability to further build muscle. Even worse, a higher amount of bodyfat increases the activity levels of the “aromatase”-enzye which converts testosterone into estrogen. Estrogen can be simply called the female antagonist to the male testosterone hormone. Estrogen leads to more body fat and a lower stimulus for muscle growth
Of course, for successful muscle building, it is necessary to ensure a constant supply of protein to the body. However, overfeeding does not result in further muscle growth but merely in storing the excess calories in the form of fat.
For this reason, one should only increase the calorie intake in a bulking phase only slightly in order to build as much muscle and as least fat as possible. In a possibly subsequent cutting phase the diet should not take too long to prevent the unnecessary loss of even more muscle mass.