A man's body is completely different to a woman's

It is completely unfair for a man to claim that they are a woman, and compete against a woman who has worked hard all of her life to be the best at what she does, only to be beaten by someone who can only compete with women because they feel they are a woman. You are either a woman or you are a man. Blurring this line is more detrimental to women than it is to men.