I can't stretch my arms straight after fitness. ..

Hello, you don't have to worry about this situation This is mainly due to muscle pain caused by lactic acid accumulation.

Guiding opinions:

This situation may last for a while, usually it will be relieved in a week or so. Now all you need to do is stretch your muscles.

Extended data:

For the human body, lactic acid is one of the fatigue substances, and it is the waste produced by the body in the process of maintaining body temperature and generating heat during physical exercise. Most of the energy our bodies need to survive comes from sugar. Blood sends glucose to various organs for combustion as needed to generate heat. In this process, water, carbon dioxide and pyruvic acid are produced, and pyruvic acid combines with hydrogen to produce lactic acid. If the body's energy metabolism can be carried out normally, it will not accumulate, and it will be brought to the liver by blood and further decomposed into water and carbon dioxide to generate heat, and fatigue will be eliminated.

If the exercise is too intense or lasts too long, or the vitamins and minerals necessary for the body to decompose lactic acid are insufficient, then the lactic acid in the body cannot be treated in time, leading to the accumulation of lactic acid. Too much lactic acid will make weakly alkaline body fluids acidic, which will affect the smooth absorption of nutrients and oxygen by cells and weaken the normal function of cells. Muscle with lactic acid accumulation will contract, thus squeezing blood vessels, making blood flow poor, leading to muscle aches, chills, headaches, top-heavy feelings and so on. Lactic acid accumulation leads to early soreness and burnout. If left unattended for a long time, it will cause acidification of the body and may cause serious diseases.

Some people sleep late on holidays to get rid of fatigue, which is ineffective. Using chemicals can only achieve temporary relief, and there are side effects. The correct way is to use proper exercise, especially stretching exercise to relax muscles, promote blood circulation, and choose balanced and light nutrition, especially foods rich in vitamin B, plus high-quality sleep, which will get the best results.

References:

Baidu encyclopedia-lactic acid