The need for glutamine supplementation for high-intensity fitness muscle building training

　　If you have been exposed to more fitness knowledge, you should not be unfamiliar with glutamine, and this part can be divided into sports nutrition. If it is a fitness book, it may mention that glutamine supplementation is recommended for muscle building trainers. Glutamine supplementation should actually be given for prolonged, exertional exercise, such as marathons.

　　What is glutamine? Glutamine, which is an important fuel for the immune system, enhances the function of the immune system. Glutamine has important immunomodulatory effects and is necessary for the secretion and proliferation of lymphocytes and the maintenance of their functions. As a precursor and main energy source for nucleic acid biosynthesis, glutamine induces mitosis and differentiation of lymphocytes and macrophages to proliferate, and increases the production of cytokines such as TNF and IL-1 and mRNA synthesis of phospholipids.

　　Turn to the last page of Schwarzenegger's Complete Fitness Book and you will see a "What's wrong with my immune system?" tab. This section actually talks about glutamine in a cursory way, but does not go into detail about why. Let's see what the book says.

　　The main food of the immune system is glutamine. Intense training puts the body under a lot of stress, and if you continue to train, you also start to deplete your body of glutamine at the same time. A natural reaction to increased training intensity is that you may find yourself becoming more susceptible to illness.

　　It was previously thought that lymphocytes and macrophages derived their energy primarily from the oxidation of sugar, but it is now clear that these cells also use glutamine for energy, and that glutamine is utilized similarly to, if not more than, glucose. There is clear evidence to support the idea that glutamine is utilized by lymphocytes and macrophages in vivo at a high rate.

　　There is evidence that the number of leukocytes and subpopulations in the blood, as well as cytokine levels, are significantly altered after prolonged and exhaustive exercise. There is a large increase in the number of leukocytes in the blood. During the immediate recovery from a marathon or heavy training, not only is the number of leukocytes in the blood increased, but the number of lymphocytes in the blood decreases below pre-training levels, as well as lymphocyte proliferation is impaired. There is now much evidence that prolonged, exhaustive exercise is associated with negative effects on immune function.

　　A final word on how to use glutamine supplements. In general glutamine is recommended to be taken after exercise before meals and before bedtime. When taking it, try to take it on an empty stomach. A total intake of 20-30 grams of glutamine a day is appropriate for exercisers. Considering the dietary intake already, if glutamine supplements are consumed, the individual supplement should not exceed 15g a day, with 10g recommended after exercise and 5g before bedtime.

　　Note

　　1. Lymphocytes

　　Lymphocyte (lymphocyte) is a type of white blood cell, the smallest white blood cell, produced by lymphoid organs, is an important cellular component of the body's immune response function. Lymphocytes are a class of cell lines with immune recognition functions and can be divided into T lymphocytes (aka T cells), B lymphocytes (aka B cells) and natural killer (NK) cells according to their migration occurrence, surface molecules and functions.

　　When stimulated by antigen, T lymphocytes are transformed into lymphoblasts, which then differentiate into sensitized T lymphocytes and participate in cellular immunity, and their immune functions are mainly to fight against intracellular infections, tumor cells and allogeneic cells, etc.; while B lymphocytes are transformed into plasma cells, which then differentiate into plasma cells, produce and secrete immunoglobulins (antibodies) and participate in humoral immunity, and their functions are to produce antibodies, present antigens, and secrete NK cells do not depend on antigen stimulation but spontaneously exert cytotoxic effects and have the role of killing target cells.

　　2. Macrophages

　　Macrophages are white blood cells located in tissues and are derived from monocytes, which in turn are derived from precursor cells in the bone marrow. Macrophages and monocytes are both phagocytes and are involved in non-specific defense (innate immunity) and specific defense (cellular immunity) in vertebrates. Their main functions are phagocytosis (i.e., phagocytosis as well as digestion) of cellular debris and pathogens in the form of fixed or free cells and activation of lymphocytes or other immune cells in response to pathogens.