Take a closer look at the difference between 1 and 2. The difference between the left reaction and the presence or absence of oxygen is oxygen, 2 no oxygen, 1 aerobic respiration and 2 anaerobic respiration. Familiar, right? Many bodybuilders say how long it takes to start anaerobic breathing during exercise, but it's all nonsense.
Unless you are in pure oxygen, your body is completely impossible, otherwise the human body has always coexisted with both, so don't believe in flipping through books. At most, your high-frequency and high-load exercise leads to insufficient oxygen intake and increased anaerobic breathing, that's all.
Therefore, if you want to enhance anaerobic breathing, you can increase the frequency of exercise, such as skipping rope. The products on the right are different. Thirty-eight ATP was produced, and only two ATP was produced, so the energy of anaerobic respiration was extremely low. Lactic acid is produced, so people will feel sore when they breathe without oxygen.
Well, here, the principle is actually very clear. You are snowing heavily in the sunny south, and I am cold as spring in the north.
Why does it turn purple when tightened and red when relaxed? Actually, you should think about the color of your blood, because the oxygen content is different. Arterial blood is rich in oxygen and bright red, while venous blood is low in oxygen and dark red.
Therefore, when you tighten your belt, the blood in the local capillaries can't get in touch with fresh oxygen, so it gets deeper and deeper. As soon as you let go, oxygen rushed to your face, and you quickly contacted oxygen, so the color recovered.