How does repeated exercise make anaerobic respiration more efficient?



I get that your body can’t produce as much energy when it lacks oxygen, but what I don’t get is how continued exercise makes it better at this.

In: Biology

When your body detects low oxygen levels, it responds by making more red blood cells. More red blood cells mean that your blood can carry more oxygen to your muscles.

There’s a neat system for how your body detects and responds to low oxygen. There are cells that are constantly producing a hormone that would instruct your bone marrow to produce more oxygen, but these cells are suppressed by a separate group of lets call guard cells. These guard cells need lots of oxygen to function though, so when there is low oxygen, they can’t surpress the hormone producing cells so your bone marrow gets the message to make more blood.

It’s like there were people who are constantly trying to send messages to the cooks to make more food, but are prevented from doing so by guards. When there is so little food that the guards pass out, the messages are able to get through to the cooks, who make more food for the guards and so they become well fed enough to prevent the messages from going out again. There’s lots of self regulating homeostasis systems like this happening in your body.

This is why athletes are encouraged to [train at high altitudes]( There’s less oxygen up there and so it triggers the same low oxygen response as exercise.

On the far extreme end. Some athletes will blood dope themselves by taking out blood cells and then re-injecting them later to artificially greatly increase their red blood cell count. This is seriously dangerous because it can make the blood so viscus that the heart isn’t able to pump it at rest. Star tour de France doping competitors would have to wake up in the middle of the night and pedal for a while just to prevent death.