Poverty and Reductions in Fitness Levels in Children and Adolescents in Upper Middle-income Countries

ncreasingly it is recognised that what happens in childhood has a significant impact on health in adulthood. As we and others have shown—social, emotional, cognitive and physical development in childhood and adolescence tracks through to later life.1 2 The paper by Tomkinson and colleagues3 examined trends in cardiorespiratory fitness (CRF) levels in childhood and adolescence. It is an important piece of work because poor fitness levels in adolescence are significantly linked with higher all-cause mortality rates later in life4 and because, as the authors illustrate in their comprehensive study, CRF fitness levels in children and adolescents in high-income and high-middle-income countries have significantly declined since the 1980s.