Clinical Nutrition University: Calorie and macronutrient requirements for physical fitness

Abstract

Optimal nutritional intakes are critical for health- and skill-related physical fitness. This course discusses 1) the effect of energy restriction and supplementation on physical fitness, 2) the optimal chronic macronutrient intakes for physical fitness in exercising subjects and 3) the impact of short-term intakes of macronutrients, before, during and after exercise, on physical fitness of athletes. In normal- or overweight subjects, hypocaloric diets in addition to physical activity enhances the maintenance of fat-free mass and may improve muscular and aerobic performance but hypercaloric diets negatively affect physical fitness. In underweight subjects, hyper- but not hypocaloric diets seem to be beneficial for physical fitness. Present knowledge does not favor different chronic macronutrient intakes for athletes than more sedentary healthy subjects. However, athletes may benefit from carbohydrate intakes at any time near exercise to improve physical fitness and recovery, and protein intakes during the recovery phase to increase muscle protein synthesis. The present standings point out that it is essential that health care providers personalize nutritional advice to meet the specific needs of exercising individuals. It highlights the difficulty of providing straight nutritional recommendations for physical fitness on the basis of evidence-based medicine. © 2011 European Society for Clinical Nutrition and Metabolism.