Effectiveness of transcutaneous auricular vagus nerve stimulation on autonomic and cardiorespiratory recovery in healthy adults after high-intensity exercise: A randomized clinical trial

Sport has high physiological demands, alternating periods of intense training and rest. Recovery periods between competitions are very short and different techniques are applied to optimize recovery. These strategies focus mainly on muscular factors associated with sports performance, leaving aside central factors such as cardiovascular, autonomic or respiratory factors. Transcutaneous auricular vagus nerve stimulation (TAVNS) is a simple and noninvasive physiotherapy technique that has been shown to restore autonomic balance, reduce inflammation and improve cardiorespiratory variables in pathological conditions, but the evidence for this technique in post-exercise recovery is limited. We hypothesize that TAVNS is an effective strategy in metabolic and cardiorespiratory recovery after high-intensity exercise. AIM: To determine the effectiveness of TAVNS on metabolic and cardiovascular recovery in healthy adults after high-intensity exercise. Material and methods: 60 healthy and physically active subjects will be randomized and assigned to 4 groups (Experimental, Sham, Control, Placebo). Each subject will perform a maximal incremental exercise test on a treadmill where their maximum oxygen consumption, respiratory quotient, minute ventilation, heart rate and variability will be analyzed. They will then be equipped with a transcutaneous electrical stimulation device with an auricular electrode to receive the intervention of their associated group for a period of 30 minutes. Expected results: We expect that the subjects in the experimental group will have a faster metabolic and cardiorespiratory recovery than the subjects in the sham, placebo and control groups.