About lactic acid

　　Lactic acid is the acid after the fermentation of milk, muscle soreness are lactic acid pot, because lactic acid is not discharged, may fitness you think scientific and reasonable to this saying. Is it really?

　　Since we are talking about lactic acid, then what exactly is lactic acid? To see what kind of origin this chemical has, we probably know from the name that it is indeed an acid isolated from milk. Specifically, lactic acid is a compound that plays a role in a variety of biochemical processes. It is a carboxylic acid with the molecular formula C3H6O3. it is a carboxylic acid containing a hydroxyl group and is therefore an alpha-hydroxy acid (AHA). In aqueous solution it releases a proton from its carboxyl group and the lactate ion CH3CHOHCOO- is produced. During the fermentation process lactate dehydrogenase converts pyruvate to levulinic acid.

　　Let's look at the production of lactic acid by fermentation. The main way of fermentation is that sugar is fermented for three to five days at about 50 or 60 dm;C under the action of lactic acid bacteria, adjusting the pH to about 5, to obtain crude lactic acid.

　　This shows that lactic acid can indeed be obtained after fermentation, but our body does not produce lactic acid as a result of fermentation. In anaerobic metabolism, when the oxygen supply does not meet the needs of muscles during strenuous exercise, muscles use adenosine triphosphate (ATP), anaerobic breakdown of creatine phosphate (CP) and anaerobic enzyme of sugar to produce lactic acid.

　　In moderate distance exercise, ATP production from aerobic and anaerobic two kinds of exercise, fitness can make the aerobic system to reach the maximum exercise capacity, this role has been limited by the muscle oxygen supply, when the glycogen into lactic acid can further produce ATP. this situation continues to maintain a period of time, or due to muscle glycogen depletion, or muscle proton accumulation will cause fatigue. The exact situation depends on the intensity and duration of the exercise, the level of training and the adaptability of the gymnast. If the rate of glycogen conversion to lactic acid is higher than the muscle's ability to remove protons, then muscle proton buildup will lead to exercise fatigue, which causes you to feel exercise fatigue.

　　Delayed soreness usually occurs the day after training. To be precise, this soreness peaks 24-72 hours after the workout and the pain largely disappears after 5-7 days. In addition to soreness, there is muscle stiffness, with only pressure pain in mild cases, or muscle swelling in severe cases, which hinders movement. Delayed muscle soreness can occur in any skeletal muscle after intense exercise.

　　Some people attribute it to the large amount of lactic acid gathered during training, which is actually incorrect. Lactic acid is produced in larger amounts along with the training process, but it quickly returns to normal levels with the cessation of training. To be precise, it basically returns to its normal state within about 40 minutes after the end of training. This means that lactic acid does not continue to build up in the muscles after training, and this delayed soreness is obviously not caused by lactic acid build-up.

　　It is currently believed that delayed soreness is caused by the following.

　　1. a dramatic increase in muscle tone and elasticity, which can cause physical damage to the structural components of the muscle.

　　2. an increase in metabolism and increased toxicity of metabolic waste products to the tissues

　　3. altered neural regulation of the muscles, causing pain due to muscle spasm.