Also known as Venus holes and is considered to be very sensual and erotic. Because of that they are named after Venus, the Roman goddess of love.
At men are also known as Apollo holes, named after the Roman god of light and sun. They are formed from the bowstrings, which grow to the pelvis and they are genetic.
Unfortunately, they can not be formed with the training or diet. Just some people have and some do not. It is not a problem if you don’t have them.
They are easier to see when the body has less body fat; they are also an indicator of good health and circulation. People with holes on their back easily come to orgasm because their genitals have better circulation.