The Age of the Individual: Operationalized Self-Research with AI for Elite Athletes vs. Population-Based Research?

Scientific research involving elite athletes serves different epistemic interests. Population-based research enables the investigation of group differences, statistical associations, and intervention effects under defined conditions. Its findings do not, however, necessarily answer how psychological processes develop over time within a particular athlete under individual performance conditions. The methodological distinction between between-person and within-person relationships is well established. Idiographic research, scientific single-case investigations, and personally initiated research (Personal Science) also have established traditions. Building on these foundations, this theoretical–methodological paper develops a further perspective: the individual elite athlete should not be exclusively an object of scientific investigation or a provider of data for research questions determined externally. The athlete’s own epistemic interests can become the starting point for a scientifically operationalized investigation of their individual history, of which the athlete is the primary intended epistemic beneficiary. Operationalized Self-Research (OSR) is further developed for this purpose as a possible individual research infrastructure. An athlete can introduce personally meaningful questions and investigate them scientifically together with qualified professionals. Such inquiry may draw on extensive multimodal longitudinal information and must take account of appropriate operationalizations, traceable analyses, alternative explanations, counterexamples, and the limits of the available information. Scientific inspectability does not require the mandatory external publication of personal findings. Recent developments in AI-supported information processing create opportunities to examine such large and heterogeneous individual datasets more systematically, investigate temporal relationships, and repeatedly address new questions. This technical possibility must be distinguished from scientific knowledge. The volume of data, machine-identified patterns, and linguistically persuasive interpretations do not, in themselves, establish sound psychological explanations or demonstrated causal relationships. The potential practical significance of this shift in perspective extends beyond the acquisition of individual knowledge. Person-specific findings could improve the scientific basis for more precisely tailored individual mental-training plans. Whether this results in psychological capabilities that remain repeatedly available under real competitive pressure across an entire season is a separate empirical question. The proposed developmental relationship is: About the athlete → for the athlete → within the athlete → over time. The transitions between scientific knowledge, personal understanding, capability development, and Agency under Pressure are expressly not treated as a necessary or already demonstrated causal chain. The Age of the Individual does not frame population-based and person-specific research as mutually exclusive alternatives. Instead, the paper develops a complementary scientific perspective that brings together individual epistemic interests, epistemic participation, professional collaboration, data control, confidentiality, and critical inspectability. Its guiding question is: How can scientific research be organized so that the individual elite athlete is not merely an object of knowledge production but can initiate, help shape, and use a scientifically grounded investigation of their own history for their development?