"Well formed gluteal muscles have long been associated with health, strength and sexual attractiveness. In terms of health, they act as a sign of 'being in shape'. This usually means a person is also eating, sleeping and exercising properly, all of which are beneficial to health. In terms of strength, the glutes are among the largest and most powerful muscles in the body. [...] If they are well formed then a person is much more likely to be able to move efficiently. In terms of sexual attractiveness, the glute specialist Bret Contreras considers in physio-anthropological terms that this is based upon a sub-conscious assessment of the relationship between a physical capability to survive and prosper, and the ability to raise a family." - Wikipedia