ABSTRACT
Carbohydrate (CHO) typically provides the majority of energy in the athlete’s diet and is essential to fuel high-intensity exercise. Ensuring adequate energy is available to meet the demands of high energy expenditure is important in the young athlete to ensure proper growth, development, and maturation. Physiological and metabolic changes that accompany the transition from childhood to adolescence and to adulthood, combined with the additional energy expenditure arising from exercise, mean that the dietary needs of young athletes require special consideration. However, in contrast to the well-documented literature in adults, little research attention has been given to child and adolescent populations. Thus, the development of specic recommendations for CHO intake in young athletes is difcult. Nevertheless, it is possible to make some general recommendations. Both the total daily CHO intake and the timing of CHO consumption in relation to exercise can determine whether adequate CHO substrate is available for muscles and the central nervous system, or whether CHO fuel sources might limit exercise performance. In terms of the overall diet, CHO should contribute to the majority of energy intake, which must be high enough to support growth and maturation while fueling the additional physical activity, and consequently elevated energy expenditure in young athletes. In particular, CHO is an important fuel for high-intensity exercise in young athletes. Decrements in exercise performance, fatigue, and changes in body composition may serve as useful indicators that CHO intake may not be adequate, particularly in female adolescent athletes. During exercise, drinks containing CHO could be considered for young athletes engaged in endurance exercise due to the preferential use of exogenous CHO in younger athletes in the pre-or early-pubertal stages. However, evidence on CHO loading and CHO for postexercise recovery does
Abstract ............................................................................................................................................ 35 3.1 Introduction ............................................................................................................................36 3.2 Recommended Values for Carbohydrate Intake for Young Athletes .....................................36 3.3 Current Levels of Carbohydrate Intake in Young Athletes .................................................... 37 3.4 Child-Adult Metabolic Differences ....................................................................................... 39 3.5 Carbohydrate Intake: Days and Hours before Endurance Exercise .......................................40 3.6 Carbohydrate Intake: During Endurance Exercise ................................................................. 42
3.6.1 Performance ................................................................................................................ 42 3.6.2 Substrate Oxidation .................................................................................................... 45
3.7 Carbohydrate Intake: Postexercise.......................................................................................... 47 3.8 Short-Duration High-Intensity Exercise and Skill Performance ............................................ 49 3.9 Sports Drinks and Hydration .................................................................................................. 49 3.10 Health, Glycemic Index, and Insulin Sensitivity ....................................................................50 3.11 Summary ................................................................................................................................ 52 References ........................................................................................................................................ 53
not appear to be available in children or adolescents. This chapter provides an overview of the available evidence that can be used to determine recommendations for CHO intake and timing in young athletes. Where no direct evidence in young athletes is available, we have relied on the relevant adult-based literature while emphasizing that the direct translation and application of these ndings to children and adolescents must be viewed cautiously.
