Abstract
Sufficient protein intake has been shown to be advantageous for developing muscle mass, muscle strength, muscle quality, as well as for improving recovery from strenuous exercise, all of which are essential for athletic performance. Aging athletes, so-called master athletes, would benefit from evidence-based recommendations; however, studies investigating the role of their protein intake on muscle quality or performance are diverse and rare. Consequently, existing recommendations for this subpopulation of aging athletes are non-existent or speculative in nature. The aim of this short scoping review is to summarize available reports, identify common outcomes, and suggest future research directions. Literature research was carried out in PubMedMedline, SPORTDiscuss, and ScienceDirect without any restrictions regarding year of publication, type of research or sports discipline. Only observational and interventional studies with data on protein intake linked with body composition or performance outcomes were included for further analyses. We identified 12 suitable reports on master athletes with very diverse age-ranges, a broad variety of sports, and very heterogeneous outcome parameters. Seven studies investigated endurance athletes, four studies investigated multi-sports athletes, and only one study reported on strength-trained athletes. Average protein intake ranged between 1.0 and 1.9 g/kg/d. Within the few available studies, evidence tends to point towards a benefit of higher protein intakes for muscle mass and function; however, the low number of studies, combined with heterogeneity in study design and methods, limits their generalizability. Future studies are needed to build the evidence base for clear dietary recommendations respecting the specific needs of aging athletes.