It is not permissible for a woman when praying to wear tight clothes that forms her `Awrah such as pants or trousers. Even if a woman goes against this ruling and prays wearing these tight clothes, her prayer is still valid, because what is required is to cover the `Awrah, and she has done that.

Although the chest is not part of the ‘awrah for men, uncovering it is still an action that is not appropriate for a man and is one of the actions of the immoral.