Recently, a study pointed out that muscular "macho men" may be more favored by women and have more sexual partners, but their immunity is weaker than that of women and less muscular men. As a result, the lifespan of "macho men" might be shorter. Men tend to have more developed muscles than women because men need to fight and hunt. From an evolutionary perspective, muscular "macho men" not only indicate better physical fitness and strength, but also represent the ability to support a family and protect their home, making them a good source of support. This ancient aesthetic view has been carried forward until today, thus women are more attracted to muscular men. The phenomenon of competing with same-sex members and showing off to opposite-sex members is a form of "sexual selection." It is this form of evolution that created deer antlers and peacock tails, and it is also the sexual selection process that created men's muscles. Being a "macho man" has many advantages. Studies show that the more developed a man's muscles are, the more sexual partners he will have in his lifetime, and his sexual experiences start earlier. However, maintaining muscles can be quite costly. Due to fierce competition, only the most muscular macho men can win the hearts of beauties, so men almost recklessly invest a large amount of resources in hopes of enhancing their sexual appeal. According to research data from a national health and nutrition survey organization, maintaining male muscles is not only expensive but also comes at the cost of health. The organization surveyed 12,000 American men and women over six years, and the results showed that men's caloric needs are 50% higher than women's, even after adjusting for different activity levels. The study also showed that men's muscle mass is the most important measure of their caloric intake, more important than their occupation and body mass index (BMI). In addition, having more muscles comes with another cost. Since men spend too many nutrients maintaining strong muscles, their immunity is much inferior to that of women. Therefore, the more muscles and denser the muscles a macho man has, the lower his immunity will be, and his lifespan may also be shorter. Historically, muscular macho men have had better mating opportunities in the short term, but less muscular men are not necessarily losers in the mating competition in the end. Although the sexual experience of weaker men may come later, since they live longer than macho men, they often adopt a "longevity" strategy, which allows them to have as many or even more sexual partners in their lifetime as macho men.