Secular trends in growth, maturation and physical performance: A review

Several aspects of research on secular trends in growth, maturity status and physical performance are reviewed with a primary focus upon data for the United States, Europe and Japan. Increases in height and weight during childhood and adolescence, reductions in the age at menarche, and increases in adult stature have occurred over several generations in Europe, Japan and United States. Secular trends in height have stopped in many developed countries while weight has continued to increase, resulting in a secular increase in overweight and obesity as indicated in the BMI. Data for body proportions are less extensive, but suggest proportionally larger increases in leg length. Corresponding trends have occurred in other developed countries (e.g., Canada, Australia, Taiwan), and to a lesser extent in many developing countries. Secular improvements in selected measures of static strength and motor performance during the last century are generally proportional to increases in body size. More recent comparisons over shorter time intervals yield more variable results and indicate changes independent of body size and more related to indicators of lifestyle, specifically changes in school programs, reduced physical activity and increased television and video games.