First of all, long-term aerobic exercise is based on fat oxidation. The popular saying is that long-distance runners are cars, and their fat is their fuel tank. Therefore, it seems absurd that a burning oil tanker doesn't look like a fuel tank. Of course, long-distance runners still look much thinner than dead fat houses (such as me), because they are not only cars, but also cars with extremely high engine efficiency and extremely low fuel consumption. This kind of car fuel tank doesn't need much natural use. ?

What are the muscle lines you are concerned about? It is the body and engine of this car (we only distinguish the leg muscles from the engine and the muscles of other parts of the body from the body structure). The pursuit of long-distance and fuel-efficient cars, the lighter the better. Large quantity, low wind resistance, demanding engine, strong power, fuel saving, lighter and more durable, which is simply the designer's requirement. Therefore, as a long-distance runner, the muscles will be developed, but not too developed, and the body will gain weight, but not too high. In short, you will find the best balance between speed and endurance, so it looks like a photo in your hair.

A healthy person, through exercise to reduce fat, body fat will not be horribly low, fat is a part of good health. As you know, 5% body fat of bodybuilders also appears this season. In fact, it is generally around 10- 15%, which has always been called slimming. For long-distance runners, that is professional athletes, aiming at sports performance, so muscle size is not what professional athletes pursue. Athletes in different sports have different muscle types. For example, sprinters are much better than long-distance runners. Is there an upper limit for long-term aerobic effect to reduce fat? Ideally, aerobic exercise will accelerate fat loss in the state of insufficient calories; However, when fat is reduced to the body and is considered to be too low to affect health, the speed of fat reduction will slow down or remain unchanged, and the heat output will be mixed more. Heat source, such as protein. But most people don't want the heat gap to be too big, for example, there is not enough heat above 1000 calories; Excessive heat output; The body does not have this stress reaction of automatically storing fat.