The vest line refers to the abdomen without fat, but it also has muscle lines. The abdomen is mainly composed of two parts, namely the abdominal muscle and the external oblique muscle, and lines will be formed between the abdominal muscle and the external oblique muscle. This is the vest line.

The mermaid line, also known as the mermaid line, is officially called the "external oblique muscle", which means that the two lines on both sides of the male abdomen near the upper pelvis form a V-shape, so it is called the mermaid line because it is similar to the slightly contracted shape of the lower part of the fish. Leonardo da Vinci first proposed "mermaid line" as an indicator of "beauty" and "sexiness" in "On Painting".

Extended data:

Female friends always care about their figure, and they can't stand too thick calves and thighs, especially the excess fat in the abdomen. Those female friends with vest lines are always jealous.

Fitness is a kind of exercise, such as all kinds of unarmed aerobics, rhythmic gymnastics, rhythmic gymnastics, and all kinds of self-resistance movements. Gymnastics can enhance the strength, flexibility, endurance, coordination and control of all parts of the body, thus making the body strong. If you want to relieve stress, exercise at least three times a week.

References:

Baidu encyclopedia-mermaid line