Influence of endurance versus resistance exercise training on central and peripheral chemoreflexes in young healthy individuals.

Abstract

Heightened central and peripheral chemoreflex sensitivity are associated with poor outcomes, but therapeutic approaches to target them are lacking. Endurance and resistance exercise training improve a multitude of physiological outcomes, but their effects on ventilatory chemoreflex sensitivity are unclear. Accordingly, the cardiorespiratory responses to steady-state isocapnic hypoxia (10 % O₂, 5-minutes) and hyperoxic hypercapnic rebreathing (5 % CO₂-95 % O₂) were compared in endurance, resistance, and untrained groups. Central chemoreflex sensitivity was taken as the slope of the relationship between minute ventilation (V̇_E) and end-tidal partial pressure of CO₂. Peripheral chemoreflex sensitivity was determined from the absolute increase in V̇_E from baseline to peak V̇_E expressed relative to the fall in oxygen saturation. Neither central (P = 0.093) nor peripheral (P = 0.847) ventilatory chemoreflex sensitivities were different between groups. Future investigations should seek to understand whether exercise training modality influences central and peripheral chemoreflex sensitivity in older and clinical populations.