How should we name the way people run? Advocating the use of ‘running repertoire’

Running is very popular worldwide, with hundreds of thousands of people enjoying this activity every day.1 Significant benefits have been largely described on the physical, mental and social aspects. The benefits result from the highly complex interaction(s) occurring between the structures and between different scales, from the molecular level to the whole organism.2 3 Based on the dynamical systems theory, these interactions shape the emerging movement while answering constraints that theoretically limit the motion of the runner. The constraints can be categorised as coming from three different sources: the environment, the task or the organism through its structural and functional specificities.4 The constraints and their interactions collectively constitute what is termed a ‘constraints constellation’, from which movement emerges.3 The variability inherent to this emerging movement is of particular interest, as its amplitude, nature and structure may be associated with either enhanced performance or elevated injury risk. Kiely2 described the observed variability in healthy runners as both ubiquitous and structured, functioning as a protective mechanism by distributing mechanical stress across a broader range of biological tissues. In terms of sport performance, variability may enable the athletes to adapt to different types of constraints without a loss in performance. Proposing a single term that gathers in a unique and unequivocal way the richness and complexity of the running movement is of utmost interest and might help in bridging gaps with other disciplines or scientific communities.