Sports knowledge: The three major energy systems of the human body

The human body is like a machine, and energy is needed to make this machine work. The fuel needed by the human body is the food we eat. After processing it through the digestive system, the nutrients in it are transformed into the energy form required by human cells through a series of metabolic processes - adenosine triphosphate (ATP, Adenosine Triphosphate).

In order to maintain life, the body organs will continue to operate, so the human body consumes energy 24 hours a day. However, the energy required during intense exercise is of course much higher than that during static activities, even about 200 times. Therefore, the body must respond quickly to it to provide sufficient energy.

Together, let’s look at the energy conversion during exercise!

The human body requires a lot of energy when exercising.

When the human body is exercising, it is achieved through muscle contraction, and muscle contraction The energy required for contraction comes from the decomposition of ATP stored in the muscles into ADP (adenosine diphosphate). However, the ATP present in muscle cells is very limited and will be depleted in about 2 to 3 seconds. In order to continue exercise, the body will continuously provide ATP for cells to use through other metabolic pathways, including:

(1) Resynthetic through the decomposition of creatine phosphate (PC);

(2) Carbohydrates are re-synthesized through the "saccharide decomposition effect (glycolysis)” is produced;

(3) Metabolize sugars, fats and proteins through oxidation.

Three energy systems during exercise

1.ATP-PC system: explosive/high power/extremely short time

The ATP-PC system or phosphide system is the fastest way for the human body to make ATP. When the ATP in muscle cells is decomposed, the Phosphocreate (PC) originally stored in muscle cells will be used to creatine kinase (Creatine) (Creatine) phosphate (PC) originally stored in muscle cells will be used to creatine kinase (Creatine) (Creatine) (Creatine) (Creatine) phosphate creatine (PC) originally stored in muscle cells at the same time will be used to creatine kinase (Creatine) (Creatine) (Creatine) (Creatine) (Creatine) phosphocreatine (PC) originally stored in muscle cells will be used to creatine kinase (Creatine) (Creatine) (Creatine) (Creatine) (Creatine) (Creatine) (Creatine) The catalytic decomposition of Kinase into creatine and phosphoric acid, and it also releases energy. The energy generated by this process can help ADP to resynthesise into ATP. However, because the number of ATP or PCs stored in muscles is not large, the ATP generated by this system mainly provides energy sources for high-intensity exercise at the beginning of exercise or within 10 seconds, such as: sprinting, baton-swinging, punching, etc.

2. Lactic Acid System: Medium power/short time

The Lactic Acid System is an energy system that will be activated when ATP and PC in muscle cells are exhausted and exercise needs to be continued. Simply put, it is to decompose glucose or liver sugar into pyruvic acid or lactic acid through glycolysis. Acid), this action will produce ATP to supply the body with the body.

However, glycolysis is an extremely complicated process. The sugars in the muscles are decomposed into pyruvate in multiple stages to generate the energy required by the muscles, and will consume ATP first and then obtain more ATP. In addition, a pair of hydrogen atoms will be generated during glycolysis, which will be received by the Nicotinamide adenine dinucleotide (NAD, a type of coenzyme) in the cell and will be reduced to NADH. When the exercise intensity increases and ATP is needed to be produced quickly and large quantities of ATP for use by muscles, glycolysis must be accelerated, and a large number of hydrogen atoms are produced. If the NAD in the cell is insufficient, the reduced NADH will be recycled by lactate dehydrogenase (Lactate). The catalysis of dehydrogenase, LDH, transfers a pair of hydrogen atoms to pyruvate to form NAD, obtaining the pyruvate of hydrogen atoms and thus reducing it to lactic acid. Therefore, this process is called the lactic acid system.

Because the lactic acid system and the ATP-PC system do not require oxygen to participate in the process, the two are also called the anaerobic system. In addition, the above substances present in the body are limited, and the lactic acid system will be completely depleted in about 30 seconds.

3. Aerobic system: low power/long time

Aerobic system (Aerobic System) is the body digests and decomposes the carbohydrates, fats and proteins it consumes, and after a series of metabolic effects, it generates energy to help the synthesis of ATP. Because aerobic participation is the name of aerobic acid in the process. The pyruvate produced in the glycolysis system and the fatty acids in the blood enter the "citric acid cycle in the pelletis mitochondria. Citric Acid Cycle” (also known as Tricarboxylic Cycle or Kerbs Cycle) to generate ATP. Because the process is complicated, it takes a long time to produce ATP.

When the intensity of exercise is low, ATP will be consumed at a slower speed, so there will be plenty of time to re-synthesis of ATP. As long as it can fully supply oxygen and intake enough sugars, proteins and fat, it can continuously supply the energy required for body exercise for a long time. This system is more active in long-distance running, brisk walking and other exercises.

Although the human body uses the above three systems to generate energy and provide muscle use, the three systems are not absolutely divided. That is to say, when performing any type of exercise, it may be mainly one of the systems, but the other two systems in the body may also produce a small amount of output at the same time.