Affiliation:
1. Graduate Program in Translational Medicine Federal University of São Paulo (Unifesp) São Paulo SP Brazil
2. Paulista Association for the Development of Medicine (SPDM) São Paulo SP Brazil
3. Department of Neuroscience ‘Rita Levi Montalcini’ University of Torino Torino Italy
4. Graduate Program in Pulmonary Medicine Unifesp São Paulo SP Brazil
5. Department of Physiology Unifesp São Paulo SP Brazil
Abstract
AbstractExercise augments the hypoxia‐induced ventilatory response in an exercise intensity‐dependent manner. A mutual influence of hypoxia‐induced peripheral chemoreflex activation and exercise‐induced muscle metaboreflex activation might mediate the augmentation phenomenon. However, the nature of these reflexes' integration (i.e., hyperadditive, additive or hypoadditive) remains unclear, and the coactivation effect on breathing‐related sensations and emotions has not been explored. Accordingly, we investigated the effect of peripheral chemoreflex and muscle metaboreflex coactivation on ventilatory variables and breathing‐related sensations and emotions during exercise. Fourteen healthy adults performed 2‐min isocapnic static handgrip, first with the non‐dominant hand and immediately after with the dominant hand. During the dominant hand exercise, we (a) did not manipulate either reflex (control); (b) activated the peripheral chemoreflex by hypoxia; (c) activated the muscle metaboreflex in the non‐dominant arm by post‐exercise circulatory occlusion (PECO); or (d) coactivated both reflexes by simultaneous hypoxia and PECO use. Ventilation response to coactivation of reflexes (mean ± SD, 13 ± 6 l/min) was greater than the sum of responses to separated activations of reflexes (mean ± SD, 8 ± 8 l/min, P = 0.005). Breathing‐related sensory and emotional responses were similar between coactivation of reflexes and the sum of separate activations of reflexes. Thus, the peripheral chemoreflex and muscle metaboreflex integration during exercise appeared to be hyperadditive with regard to ventilation and additive with regard to breathing‐related sensations and emotions in healthy adults.
Funder
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Subject
Physiology,Physiology (medical),Nutrition and Dietetics,Physiology,Physiology (medical),Nutrition and Dietetics