Abstract

The longitudinal data reported in this HK Sport Science Monograph are from the Amsterdam Growth Study. This 15-year multidisciplinary investigation was carried out between 1976 and 1991 with a group of almost 100 males and 100 females in the Netherlands living in and around Amsterdam. The study is in progress and will continue with repeated measurements in the near future. The general purposes of this longitudinal study are to describe the physical and mental development of a group of males and females from the teen years to adulthood and to find out whether there are periods of change in health status and, if so, to elaborate their possible causes. We monitored aspects of lifestyle, such as nutrition and physical activity, and several psychosocial variables. These factors are thought to have an impact on the development of health in young people. Four yearly measurements were made in teenagers aged 13 to 17 years, and later two measurements were made at ages 21 and 27. After a general introduction the purpose and setup of this study are described in Part I. We pay special attention to the 'multiple longitudinal design' and to the measures taken to prevent selective dropout and to promote the adherence of the subjects. We describe the multidisciplinary methods that are used, including the assessment of body growth, body composition, physical fitness, physiological and psychological characteristics, nutritional intake, and daily physical activity. Part II describes the longitudinal changes of (a) body growth and body composition in terms of body mass and fat mass; (b) physiological fitness in terms of maximal oxygen uptake, muscle force, speed, flexibility, and indicators for cardiovascular diseases; and (c) psychological traits, such as personality, attitude, type A or B behavior, and life events over the 15-year period. The important lifestyle patterns under review in this study are described in Part Ill, which concerns the changes in dietary intake (including alcohol and smoking behavior), daily habitual physical activity, stress, behavioral style, and health complaints that subjects reported. Six points in time are available, giving a fairly good pattern of change over the 15-year period of these males and females. Part IV contains six chapters describing relations between lifestyle and health in the study's population. Chapter 9 describes the relationship between physical activity level and fitness parameters, and chapter 10 concerns the relationships between physical fitness and the incidence of sports injury and the health of subjects. Chapter 11 concerns tracking analyses of cardiovascular risk indicators (such as hypercholesterolemia, hypertension, percentage of body fat, smoking) and psychological characteristics (such as stress, Type A or B behavior) and the incidence of daily hassles and life events. In the last year of measurement (1991) bone mineral density was also measured in the lumbar spine of subjects at age 27. This is the age at which peak bone density is thought to occur. In chapters 12 and 13 the possible influence of calcium intake and weight-bearing activities (measured during the previous 15 years) on the development of peak bone density in the lumbar spine is assessed. The last chapter is devoted to an analysis of the effects on adult health of physical condition and lifestyle in the adolescent period. In the final section the main conclusions of the longitudinal study are drawn. Preventive strategies for increasing health and avoiding diseases at young-adult age and even in older years are suggested. The four parts of this book are divided into chapters written by one or more authors in the form of a scientific article with references listed at the end. aus dem Vorwort