From Medium:

Medium discusses the use of a sports bra during exercise. Celebrity Physical Therapist Dr. Karena Wu is the AVP Medical Director. The AVP is America’s professional beach volleyball tournament series. She works with professional beach volleyball athletes when on the road and the normal layperson back in her clinics in NYC and Mumbai. Her work on the AVP in the medical tent has shown her that many female athletes use a sports bra, instead of their bikini tops (their normal bikini ‘work’ outfit), with due reason. To read how to protect your ‘girls’, click here.