This paper focuses on the role of Ecological Dynamics as a theoretical framework for analysing performance of athletes and sports teams as complex adaptive systems. It combines key concepts from ecological psychology and nonlinear dynamical system theory, seeking to enhance understanding of performance and learning contexts in sport, to aid the acquisition and transfer of adaptive human behaviours. In ecological psychology the continuous regulation of human behaviour is predicated on the role of information that emerges from the individual–environment system to guide activity. The information sources that constrain performance behaviours are affordances, which provide invitations for action offered by each individual's perception of functional relations with a performance environment. This information-based approach has been enhanced with the integration of tools and concepts from nonlinear dynamics to explain how information is cyclically related to the dynamics of a performance environment. Dynamical systems theory addresses the emergence of coordination tendencies that exist between and within components and levels of complex neurobiological systems. Ecological Dynamics identifies key properties of expertise in sport predicated on the performer-environment relationship as the appropriate scale of analysis. This paper introduces the key properties of expert movement systems that include multi-and meta-stability, the functional role of adaptive movement variability, redundancy, degeneracy and the attunement to affordances. Additionally, we discuss the concept of representative design, which in an ecological dynamics framework underpins the organisation of experimental and learning environments so that observations and acquired skills can be linked to emergent functional behaviours in a specific performance context.