Physical activity, Living healthy, Access, Youth development, and Safety in Youth Sports Act or the PLAYS in Youth Sports Act This bill directs the Centers for Disease Control and Prevention (CDC) to establish a program to award grants to eligible national nonprofit organizations to improve the health and positive youth development impacts of youth sports participation and to increase access to youth sports for all children and youth, especially underserved populations. The activities supported include training and certification programs for coaches; training for youth development and character development; instructing positive parental involvement; developing and implementing coach and volunteer retention efforts; fostering a positive sport experience for all involved that emphasizes athlete development over winning at all costs; and activities to enhance effects beyond the playing field, such as with respect to nutrition practices, academic performance, encouragement of life-long practices, and promotion of positive self-image. The bill sets forth provisions regarding background checks of coaches, mentors, and other adults with access to youth sports participants. The Department of Health and Human Services (HHS) may establish a program to award grants to municipalities, counties, and states to fund efforts to establish and implement model standards, such as through surveys, studies, pilot programs, and guidelines, for out-of-school youth sports coaches. The Government Accountability Office and HHS must report to Congress regarding youth sports. The bill authorizes the CDC and the National Institutes of Health to undertake, support, enhance, and expand research and prevention efforts to advance youth sports safety.