The Adaptive Cellular State Model: A Conceptual Framework Linking Dietary Quality to Exercise-Induced Cellular...

Exercise is a recurrent multidimensional perturbation that initiates biological adaptation, yet responses to comparable training programmes remain heterogeneous. This critical narrative Review introduces the Adaptive Cellular State (ACS) Model as a heuristic framework for examining how the biological context present before training may contribute to variation in the subsequent processing and consolidation of exercise-induced perturbations. ACS is defined as a pre-existing, dynamic and multidimensional biological configuration that may condition how exercise-induced perturbations are received, decoded, executed and retained across repeated adaptive cycles. The model organizes nine interacting domains-mitochondrial quality, metabolic flexibility, nutrient sensing, redox responsiveness, inflammatory tone, microbiota-derived signalling, endothelial function, proteostasis and epigenetic readiness-and proposes four emergent properties: gain, fidelity, biological noise and memory. These domains and properties are theoretical constructs rather than validated ACS measurements or clinical categories. Exercise remains the indispensable initiating stimulus, whereas nutrition may act through distinct routes: acute nutritional conditions may modify the internal perturbation generated during exercise, habitual dietary quality may influence selected components of the pre-existing biological context, and recovery nutrition may provide substrates or modify conditions relevant to remodelling. Nutrient-adequate dietary patterns emphasizing minimally processed foods and a diverse plant-food component represent plausible candidate exposures, but current evidence does not establish superiority over appropriately constructed high-quality omnivorous patterns or demonstrate greater long-term training adaptation. The ACS Model should therefore be interpreted as a prospective and falsifiable research framework whose validity depends on whether prespecified baseline ACS-related measures provide reproducible information about durable adaptation beyond conventional metabolic, fitness and training-history variables.