Adolescent Female Humans 5 adolescent 5 female 5 human 5 Male 4 adult 4 male 4 Adult 3 Article 2 Middle Aged 2 Young Adult 2 article 2 athlete 2 epidemiology 2 major clinical study 2 middle aged 2 physical activity 2 psychology 2 young adult 2 Aged 1 Athletes 1 Athletic Injuries 1 Athletic Performance 1 COVID-19 1 Centers for Disease Control and Prevention (U.S.) 1 Child 1 Chronic Traumatic Encephalopathy 1 Cross-Sectional Studies 1