Dietary Protein for Training Adaptation and Body Composition Manipulation in Track and Field Athletes

Abstract

Track and field athletes engage in vigorous training that places stress on physiological systems requiring nutritional support for optimal recovery. Of paramount importance when optimising recovery nutrition are rehydration and refuelling which are covered in other papers in this volume. Here, we highlight the benefits for dietary protein intake over and above requirements set out in various countries at ~0.8-1.0 g/kg body mass (BM)/day for training adaptation, manipulating body composition, and optimising performance in track and field athletes. To facilitate the remodelling of protein-containing structures, which are turning over rapidly due to their training volumes, track and field athletes with the goal of weight maintenance or weight gain should aim for protein intakes of ~1.6 g/kg BM/day. Protein intakes at this level would not necessarily require an over-emphasis on protein-containing foods and, beyond convenience, does not suggest a need to use protein or amino acid-based supplements. This review also highlights that optimal protein intakes may exceed 1.6 g/kg BM/day for athletes who are restricting energy intake and attempting to minimise loss of lean body mass. We discuss the underpinning rationale for weight loss in track and field athletes, explaining changes in metabolic pathways that occur in response to energy restriction when manipulating protein intake and training. Finally, this review offers practical advice on protein intakes that warrant consideration in allowing an optimal adaptive response for track and field athletes seeking to train effectively and to lose fat mass while energy restricted with minimal (or no) loss of lean body mass.