Neuromodulation of the Autonomic Nervous System in Athletes

Not Applicable

Recruiting

• Conditions: Fatigue, Mental; Fatigue; Combat; Efficacy, Self; Fatigue; Muscle, Heart
• Interventions: Device: tVNS

• Registration Number: NCT06281795
• Lead Sponsor: Bakulev Scientific Center of Cardiovascular Surgery

Brief Summary

There are few studies in the literature that have evaluated the effects of using percutaneous stimulation of the auricular branch of the vagus nerve for sports purposes (to accelerate recovery after physical exertion). It has been demonstrated that tVNS in athletes improved the rate of heart rate recovery, reduced lactic acid levels in blood plasma, reduced pain, reduced overtraining syndrome and fatigue levels.

Detailed Description

Several studies have shown that transcutaneous vagus nerve stimulation (tVNS) potentially exhibits therapeutic effects similar to its invasive counterpart. tVNS is performed using surface electrodes and low-frequency electrical currents, targeting specific locations, most commonly the auricular branch of the vagus nerve or its cervical branch.

Stimulation of the auricular branch of the vagus nerve activates vagal sensory fibers, simulating sensory input to the brainstem and forming what is known as the auriculo-vagal afferent pathway. Since these fibers project directly to the nucleus of the solitary tract (also known as the solitary tract nucleus), which in turn has direct or indirect projections to nuclei that provide noradrenergic, endorphinergic, and serotonergic fibers in various parts of the brain, regulating systemic parameters of cardiovascular, respiratory, and immune functions, it can be expected that the body's response to stimulation of the auricular branch of the vagus nerve will be systemic.

With the onset of physical exercise, sympathetic activity in the body increases and reaches a plateau value after a certain period of maximum activity. After the end of physical exercise, suppressed parasympathetic activity begins to intensify, and the sympathetic system gradually returns to a resting state. After training, parasympathetic system activation continues for up to 48 hours. In certain types of training, when the frequency of anaerobic respiration increases during physical exertion, a decrease in parasympathetic reactivation may be observed.

In the literature, there are individual studies that have evaluated the effects of transcutaneous stimulation of the auricular branch of the vagus nerve for sports purposes (to accelerate recovery processes after physical exertion). It has been demonstrated that tVNS in athletes improves heart rate recovery, reduces lactate levels in plasma, reduces pain sensations, decreases overtraining syndrome, and reduces fatigue levels.

The aim of this study is to: evaluate the influence of low-frequency electrical stimulation of the auricular branch of the vagus nerve on the functional reserve of the cardiovascular and respiratory systems in athletes during the post-training period, after high-intensity workouts.

Study Timeline

• Study First Submitted: 2024-02-19
• Study First Submitted QC: 2024-02-26
• Study First Posted: 2024-02-28
• Study Start: 2024-04-01
• Status Verified: 2024-06
• Last Update Submitted: 2024-06-04
• Last Update Posted: 2024-06-05
• Primary Completion: 2025-01-31
• Study Completion: 2026-01-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 125

Inclusion Criteria

• Professional athletes over the age of 15 and under the age of 35;
• Cyclic sports (swimming, modern pentathlon, athletics, triathlon);
• Difficult coordination sports (dance sports, rhythmic gymnastics);
• Sports category: no lower than candidate for master of sports;
• Voluntary informed consent.

Exclusion Criteria

• Atypical and unrelated to physical exertion changes on the ECG (T wave inversion, st-segment depression, pathological Q waves, signs of left atrial enlargement, signs of right ventricular hypertrophy, ventricular pre-excitation, complete right or left bundle branch block, prolonged or shortened Q-T interval, Brugada-like early repolarization);
• Heart rhythm and conduction disorders (frequent ventricular and supraventricular extrasystoles, first-degree atrioventricular block (P-Q > 0.21 s, not shortened during hyperventilation or physical exertion), second or third degree);
• Expressed sinus bradycardia with resting heart rate < 40 bpm;
• Taking glucocorticosteroids in the last 1 month;
• Taking any antiarrhythmic drugs, including beta-blockers.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Active tVNS	tVNS	Active stimulation will be carried out using the tVNS device with an ear clip attached to the left earlobe at a frequency of 20 Hz, 200 μs at a current slightly below the discomfort threshold. The device's operating mode is active therapeutic.
Sham tVNS	tVNS	Fictitious stimulation will be carried out using the tVNS device with an ear clip attached to the left earlobe at a frequency of 20 Hz, 200 μs at a current slightly below the discomfort threshold. The device's operating mode is research mode.

Primary Outcome Measures

Name	Time	Method
Dynamics of maximum oxygen consumption (VO2max).	The level of VO2max is estimated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the active and fictitious stimulation groups.	During a cardiorespiratory exercise test, the level of VO2max (ml/min/kg) is assessed.
The dynamics of the treadmill speed at the level of the anaerobic threshold of metabolism.	Treadmill speed is estimated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the active and dummy stimulation groups.	During the cardiorespiratory exercise test, the treadmill speed (km/h) is estimated at the level of the anaerobic metabolic threshold.

Secondary Outcome Measures

Name	Time	Method
The dynamics of the heart rate (HR) at the level of the anaerobic threshold of metabolism.	HR is estimated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the active and dummy stimulation groups.	During the cardiorespiratory exercise test, the HR is estimated at the level of the anaerobic metabolic threshold.
The dynamics of the heart rate (HR) at the level of the aerobic threshold of metabolism.	HR is estimated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the active and dummy stimulation groups.	During the cardiorespiratory exercise test, the HR is estimated at the level of the aerobic metabolic threshold.
HF dynamics	This parameter is evaluated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the groups of active and fictitious stimulation.	During the spectral analysis of heart rate variability, the HF (high frequency) parameter is estimated.
The dynamics of RMSSD.	This parameter is evaluated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the groups of active and fictitious stimulation.	During the time analysis of heart rate variability, the RMSSD parameter is estimated.
Dynamics of the treadmill speed at the level of the aerobic metabolism threshold of metabolism.	Treadmill speed is estimated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the active and dummy stimulation groups.	During the cardiorespiratory exercise test, the treadmill speed (km/h) is estimated at the level of the aerobic metabolic threshold.
Dynamics of the LF/HF ratio.	This LF/HF ratio is evaluated at the beginning of the study (initially) and at the end of the study (after 8 weeks) in the active and fictitious stimulation groups.	The LF/HF ratio is estimated during the spectral analysis of heart rate variability.

Trial Locations

Locations (1)

Autonomous Non-Profit organization of additional education sports school BECOME A CHAMPION; 🇷🇺 Krasnodar, Russian Federation