The Effect of Auricular Vagus Nerve Stimulation and Controlled Breathing Exercises on Performance and Autonomic Nervous System

NCT ID: NCT06796101

Last Updated: 2025-12-09

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 64 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-07-09
• Study Completion Date: 2025-12-05

Brief Summary

There are many studies in the literature on transcutaneous vagus nerve stimulation (VNS) and controlled breathing exercises (CBE), but there are limited studies examining the effects of both interventions on performance and the autonomic nervous system.

The investigators aim to contribute to the literature by examining the effects of VNS and CBE on performance and the autonomic nervous system in moderately physically active individuals and their superiority over each other.

Detailed Description

The sympathetic and parasympathetic divisions of the autonomic nervous system affect the function of many organs, glands, and involuntary muscles in the body. The sympathetic and parasympathetic nervous systems often play opposing roles in the body, one is suppressed when the other increases activity. With the beginning of exercise or sports activity, sympathetic activity in the body increases and after a certain period reaches a plateau value at maximum activity. With the end of sports activity, the suppressed parasympathetic activity increases, and the sympathetic system returns to its resting state over time.

Low sympathetic activity and/or high parasympathetic activity and low heart rate before training or exercise can be considered as performance indicators. It also indicates that recovery from the previous training or exercise is adequate. Parasympathetic system activation continues for up to 48 hours after exercise. If the exercise is intense and persistent, parasympathetic system activity can last up to 72 hours. In addition, due to the increase in anaerobic respiratory rate during exercise, there may be decreases in parasympathetic reactivation.

Transcutaneous vagus nerve stimulation (VNS) can affect cardiovascular parameters both at rest and during exercise. VNS improves autonomic modulation and positively reduces pain and fatigue associated with cycling exercise. On the other hand, VNS is particularly useful in reducing pain and fatigue during and after competition.

Slow breathing modulates the activity of the vagus nerve. Controlled breathing exercises (CBE) directly affect the respiratory rate, which can lead to faster physiological and psychological calming effects by increasing vagal tone during slow expiration. CBE increase heart rate variability in healthy participants.

The investigators aim to contribute to the literature by examining the effects of VNS and CBE on performance and the autonomic nervous system in moderately physically active individuals and their superiority over each other.

Conditions

Health People; Physical Activity; Autonomic Nerveus System; Vagus Nerve Stimulations

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: NONE

Study Groups

Transcutaneus vagus nerve stimulation

This group will receive Transcutaneous vagus nerve stimulation from bilateral ear for two weeks, 10 sessions.

Group Type: EXPERIMENTAL

Vagus Nerve Stimulation

Intervention Type: DEVICE

In the study, CE certified vagus nerve stimulation device Vagustim will be used. Transcutaneous auricular vagus nerve stimulation will be applied bilaterally. The stimulation pulse width is 300 microseconds, frequency is 10 Hz and will be applied biphasically for 20 minutes.

Controlled breathing exercise group

Controlled breathing exercises include thoracic expansion exercises, Nadi Shodhana Pranayama, Bhramari Pranayama, Kapalabhati and Physiological-sighing exercises.

Group Type: EXPERIMENTAL

Controlled breathing exercises

Intervention Type: OTHER

A controlled breathing exercise group will continue for a total of 2 weeks and will receive 10 sessions of 20 minutes per day.

The thoracic expansion exercise will be performed in 10 repetitions. In each intervention session, 2 sets of nadi shodhana pranayama consisting of 8 respiratory cycles will be applied to the patients, with a 2-minute rest period between the sets. Kapalabhati will be practised for 3 minutes, with 15 quick breaths in 10 seconds followed by a 20-second break (a total of 30 breaths per minute). In each session, 2 sets of bhramari pranayama consisting of 10 breathing cycles will be performed at a low respiratory rate, with a 1-minute rest period between sets. The physiological sigh exercise involves the first inspiration phase being 1 second, the second phase 0.25 seconds, and the exhalation 2 seconds for 3 minutes.

Interventions

Vagus Nerve Stimulation

In the study, CE certified vagus nerve stimulation device Vagustim will be used. Transcutaneous auricular vagus nerve stimulation will be applied bilaterally. The stimulation pulse width is 300 microseconds, frequency is 10 Hz and will be applied biphasically for 20 minutes.

Intervention Type: DEVICE

Controlled breathing exercises

A controlled breathing exercise group will continue for a total of 2 weeks and will receive 10 sessions of 20 minutes per day.

The thoracic expansion exercise will be performed in 10 repetitions. In each intervention session, 2 sets of nadi shodhana pranayama consisting of 8 respiratory cycles will be applied to the patients, with a 2-minute rest period between the sets. Kapalabhati will be practised for 3 minutes, with 15 quick breaths in 10 seconds followed by a 20-second break (a total of 30 breaths per minute). In each session, 2 sets of bhramari pranayama consisting of 10 breathing cycles will be performed at a low respiratory rate, with a 1-minute rest period between sets. The physiological sigh exercise involves the first inspiration phase being 1 second, the second phase 0.25 seconds, and the exhalation 2 seconds for 3 minutes.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Individuals with a moderate level of physical activity according to the International Physical Activity Scale
• No orthopedic obstacle to exertion
• Being male

Exclusion Criteria

• Having any active or chronic disease
• Having cooperation problems
• Using regular medication for any chronic condition within the last year
• Being a smoker
• Having had heart surgery
• Having had surgery on the respiratory system

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 35 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Bahçeşehir University

OTHER

Sponsor Role: lead

Responsible Party

Okan Sahin

Principal Investigator, PT (Physiotherapist), MSc

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Okan ŞAHİN, PT, MSc

Role: PRINCIPAL_INVESTIGATOR

Bahçeşehir University

Ali Veysel ÖZDEN, MD, PHD

Role: STUDY_DIRECTOR

Bahçeşehir University

Locations

Bahçesehir University

Istanbul, Istanbul, Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

ODRP-2025

Identifier Type: -

Identifier Source: org_study_id