Hyrox®: Current Evidence on Physiology, Psychology and Performance Determinants

Background: Functional fitness has evolved from a niche training methodology into an influential movement in contemporary exercise science, sports performance, and the fitness industry. Among the competitive formats that have recently emerged, Hyrox® has become a prominent standardized model of hybrid fitness competition. This review aimed to critically synthesize the available evidence on the development of Hyrox® and its physiological demands, psychological characteristics, and performance determinants. Methods: Given the limited evidence available, a narrative review was conducted. PubMed, Scopus, and Web of Science were searched for original and review articles investigating Hyrox® athletes or participants. The evidence was synthesized across three major domains: physiology, psychology, and performance determinants. Results: Eleven studies were included, comprising eight original articles and three review articles. The available evidence indicates that Hyrox® imposes sustained high metabolic and per-ceptual demands, with functional stations eliciting particularly elevated blood lactate concentrations. Running capacity consistently emerged as the strongest determinant of overall performance. Psychological, recovery, sleep, and injury-related aspects remain insufficiently investigated. Conclusions: Hyrox® represents a promising research model for hybrid fitness because of its standardized competition format and rapidly growing international participation. However, the evidence base remains limited and is pre-dominantly derived from observational studies and analyses of publicly available competition data. Controlled interventions, longitudinal monitoring, and physiological, biomechanical, and psychosocial investigations are required to support evidence-based recommendations for athlete preparation and competition.