Time to reconsider how ventilation is regulated above the respiratory compensation point during incremental exercise

The regulation of ventilation during incremental exercise beyond the respiratory compensation point (RCP) has traditionally been attributed to metabolic acidosis-driven stimulation of chemoreceptors. However, emerging evidence suggests that this explanation may be incomplete. In this review, we analyze the ventilatory response above RCP, emphasizing the disproportionate increase in minute ventilation (\(\dot{V}_E\)) relative to carbon dioxide output (\(\dot{V}_{CO_2}\)). We propose that this response is primarily driven by a nonlinear increase in respiratory frequency (\(f_R\)), rather than tidal volume (\(V_T\)). This distinction challenges conventional models of ventilatory control and suggests that mechanisms beyond metabolic acidosis, such as cortical drive and sensory feedback, may play a more significant role in modulating ventilation during high-intensity exercise. A re-evaluation of ventilatory regulation incorporating these factors could enhance our understanding of exercise physiology and improve interpretations of ventilatory thresholds in both research and clinical settings.