This bachelor's thesis deals with the syndrome of Relative
Energy Deficiency in Sport (REDs) among athletes in strength,
aesthetic, and functional disciplines. The theoretical part
defines the concept of energy availability, maps the
physiological impacts of REDs, and identifies specific risk
factors in weightlifting, powerlifting, bo-dybuilding, and
CrossFit. The main aim of the thesis is to determine the
prevalence of REDs risk in a selected group of active athletes
(n = 24) through a quantitative survey using the RST screening
tool. The results indicate a high level of risk associ-ated
with chronic psychological pressure and extreme training
volume, while also suggesting a protective effect of strength
training on bone health even under con-ditions of energy
deficit. The thesis emphasizes the need for better education in
sports nutrition and mental health support for athletes.