Vagus Nerve StimulationsNCT06985043
The Effect of Vagus Nerve Stimulation on Lower Limb Muscle Strength and Balance in Nonelite Athletes
A study testing Auricular vagus nerve stimulation (AVNS) in people with Vagus Nerve Stimulations and Muscle Strength, run by Bahçeşehir University at 1 site in Turkey (Türkiye).
Trial summary
Clinical Trials (Non-Randomized Controlled) The aim of this study is to evaluate whether vagus nerve stimulation can improve neuromuscular and functional outcomes in non-elite athletes aged 18-35 years living in Istanbul. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Vagus Nerve Stimulations, Muscle Strength, Balance
- What is being tested?
- Auricular vagus nerve stimulation (AVNS)
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 25 May 2025to 25 Jul 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- body mass index (BMI) between 18.5-25 kg/m²
- exercising for a total of 3 hours or more per week for at least three months
Who cannot join
- have a chronic musculoskeletal disease
Trial locations and contacts
1 site in 1 country.
About this study
Clinical Trials (Non-Randomized Controlled) The aim of this study is to evaluate whether vagus nerve stimulation can improve neuromuscular and functional outcomes in non-elite athletes aged 18-35 years living in Istanbul.
The main questions it aims to answer are:
Read more
Does vagus nerve stimulation improve neuromuscular performance? Does it have a positive effect on functional performance? Researchers will compare the vagus nerve stimulation group to a control group to see if the intervention leads to significant improvements in neuromuscular and functional outcomes.
Participants will: Be selected based on criteria including age (18-35 years), non-elite athletic status (minimum two months), exercising 2-5 days per week for approximately 3.2 hours on average Have a Body Mass Index (BMI) between 18.5-25 kg/m² Participate voluntarily Exclusion criteria include:Any disease affecting the inner or outer ear BMI below 18.5 kg/m² or above 25 kg/m²
Read the detailed description
The vagus nerve (VN), the tenth cranial nerve, is a key component of the neuroendocrine-immune axis and plays a critical role in regulating autonomic functions such as cardiovascular, endocrine, respiratory, and digestive system activity through its extensive central and peripheral connections (1,2). Non-invasive vagus nerve stimulation (VNS), particularly through auricular stimulation, has been shown to modulate autonomic balance by reducing sympathetic activity, enhancing cardiac baroreflex sensitivity, and improving parasympathetic tone (3,4).
In the context of athletic performance, the autonomic nervous system's role in adaptation to training and recovery is well recognized (5). Post-exercise parasympathetic reactivation is increasingly used as a biomarker for recovery and performance enhancement. Auricular VNS (aVNS), by stimulating afferent auricular branches of the VN, may facilitate recovery by reducing exercise-induced fatigue, pain, and lactate accumulation, while improving parasympathetic activity (3). Importantly, these physiological effects have been observed without significant alterations in heart rate or blood pressure.
Balance training is a known contributor to improved functional performance in athletes, and neuromuscular control is essential for injury prevention and overall athletic capacity (6). Considering the limited research on the effects of aVNS on neuromuscular parameters such as muscle strength and balance response in non-elite athletic populations, this study aims to provide evidence on the efficacy of aVNS in this context.
This study is designed as a non-randomized controlled trial. Thirty non-elite athletes aged 18-35 years, who have been physically active for at least three months and currently exercise 2-5 days per week (averaging 3.2 hours per week), will be recruited. Eligible participants must have a BMI between 18.5 and 25 kg/m² and provide informed consent. Individuals with conditions affecting the inner or outer ear or BMI values outside the specified range will be excluded.
The intervention group will receive a single session of bilateral aVNS using a biphasic, asymmetric waveform at a frequency of 25 Hz, pulse width of 300 microseconds, applied continuously for 20 minutes. The post-intervention follow-up period will last 30 minutes (3).
Assessment Parameters
Demographic and Baseline Characteristics:
Collected via a structured interview, including age, gender, height, weight, weekly exercise volume, and auditory health status.
Balance Assessment:
Balance will be evaluated using the Biodex Balance System, which quantifies postural sway and center of pressure (COP) metrics. Tests will be performed under both eyes-open and eyes-closed conditions, with three trials conducted for each. Lower sway index values indicate better balance performance (7).
Muscle Strength Assessment:
Maximal isometric strength of the quadriceps femoris and hamstring muscles will be measured using a Hand-Held Dynamometer (HHD). For quadriceps testing, participants will be seated with knees flexed to 90°, and the dynamometer placed 1-2 cm above the malleoli. For hamstring assessment, participants will lie prone with knees flexed to 90°. The "make test" method will be used, where the participant applies maximal voluntary contraction against a stationary dynamometer held by the examiner. Each muscle group will be tested three times with 60-second rest intervals, and the average value will be used for analysis (8).
- Conditions
- Vagus Nerve Stimulations, Muscle Strength, Balance
- Being tested
- Auricular vagus nerve stimulation (AVNS)
- Keywords
- vagus nerve stimulations, nonelite athletes, muscle strength, balance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Auricular vagus nerve stimulation (AVNS)Device
Auricular vagus nerve stimulation (AVNS) will be applied to both ears simultaneously, using a biphasic, asymmetric waveform with pulses of 300 microsecond duration and a frequency of 25 Hz, continuously for 20 minutes. The application will be performed in a single session and the follow-up time will be determined as 30 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Vagus nerve stimulation | Experimental | Auricular vagus nerve stimulation (AVNS) will be applied to both ears simultaneously, using a biphasic, asymmetric waveform with pulses of 300 microsecond duration and a frequency of 25 Hz, continuously for 20 minutes. The application will be performed in a single session and the follow-up time will be determined as 30 minutes. Receives: Device: Auricular vagus nerve stimulation (AVNS) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Muscle strenght
Muscle strength of quadriceps femoris and hamstring muscles will be evaluated by hand dynamometer.
Measured: Baseline and after the vagus stimulation apply
Balance
Postural sway will be assessed by biodex balance with center of gravity characteristics anterior-posterior and lateral sway with eyes closed and open.
Measured: Baseline and after the vagus stimulation apply
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 May 2025
- Study start25 May 2025
- Primary completion25 Jul 2025
- Study completion25 Jul 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Vagus Nerve StimulationsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bahçeşehir University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tuğçe Poyraz İşleyen, Bahçeşehir University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06985043
- Sponsor's protocol ID
- E-10840098-202.3.02-2218
- Status last verified
- Jul 2025
- First submitted
- 15 Apr 2025
- Last updated
- 5 Aug 2025
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Peller A, Garib R, Garbe E, Komforti D, Joffe C, Magras A, Trapuzzano A, Stock MS, Dawson NT. Validity and reliability of the NIH Toolbox(R) Standing Balance Test As compared to the Biodex Balance System SD. Physiother Theory Pract. 2023 Apr;39(4):827-833. doi: 10.1080/09593985.2022.2027584. Epub 2022 Jan 23.
PubMed 35068342Unver B, Bakirhan S, Karatosun V. Does a weight-training exercise programme given to patients four or more years after total knee arthroplasty improve mobility: A randomized controlled trial. Arch Gerontol Geriatr. 2016 May-Jun;64:45-50. doi: 10.1016/j.archger.2016.01.003. Epub 2016 Jan 6.
PubMed 26952376Hrysomallis C. Balance ability and athletic performance. Sports Med. 2011 Mar 1;41(3):221-32. doi: 10.2165/11538560-000000000-00000.
PubMed 21395364Hatik SH, Arslan M, Demirbilek O, Ozden AV. The effect of transcutaneous auricular vagus nerve stimulation on cycling ergometry and recovery in healthy young individuals. Brain Behav. 2023 Dec;13(12):e3332. doi: 10.1002/brb3.3332. Epub 2023 Nov 16.
PubMed 37974551Caliota A, Ozden AV, Ceylan I. Effects of a single session of noninvasive auricular vagus nerve stimulation on sports performance in elite athletes: an open-label randomized controlled trial. Expert Rev Med Devices. 2024 Mar;21(3):231-237. doi: 10.1080/17434440.2023.2299300. Epub 2023 Dec 30.
PubMed 38146234Yuan H, Silberstein SD. Vagus Nerve and Vagus Nerve Stimulation, a Comprehensive Review: Part I. Headache. 2016 Jan;56(1):71-8. doi: 10.1111/head.12647. Epub 2015 Sep 14.
PubMed 26364692Prescott SL, Liberles SD. Internal senses of the vagus nerve. Neuron. 2022 Feb 16;110(4):579-599. doi: 10.1016/j.neuron.2021.12.020. Epub 2022 Jan 19.
PubMed 35051375
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Vagus Nerve Stimulation on Lower Limb Muscle Strength and Balance in Nonelite Athletes
- ClinicalTrials.gov ID
- NCT06985043
- Acronym / sponsor ID
- E-10840098-202.3.02-2218
- Conditions
- Vagus Nerve Stimulations, Muscle Strength, Balance
- Keywords
- vagus nerve stimulations, nonelite athletes, muscle strength, balance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Bahçeşehir UniversityUniversity, hospital or other
- Study start
- 25 May 2025 (actual)
- Primary completion
- 25 Jul 2025 (actual)
- Study completion
- 25 Jul 2025 (actual)
- First posted
- 22 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Clinical Trials (Non-Randomized Controlled) The aim of this study is to evaluate whether vagus nerve stimulation can improve neuromuscular and functional outcomes in non-elite athletes aged 18-35 years living in Istanbul.
The main questions it aims to answer are:
Does vagus nerve stimulation improve neuromuscular performance? Does it have a positive effect on functional performance? Researchers will compare the vagus nerve stimulation group to a control group to see if the intervention leads to significant improvements in neuromuscular and functional outcomes.
Participants will: Be selected based on criteria including age (18-35 years), non-elite athletic status (minimum two months), exercising 2-5 days per week for approximately 3.2 hours on average Have a Body Mass Index (BMI) between 18.5-25 kg/m² Participate voluntarily Exclusion criteria include:Any disease affecting the inner or outer ear BMI below 18.5 kg/m² or above 25 kg/m²
Detailed description
The vagus nerve (VN), the tenth cranial nerve, is a key component of the neuroendocrine-immune axis and plays a critical role in regulating autonomic functions such as cardiovascular, endocrine, respiratory, and digestive system activity through its extensive central and peripheral connections (1,2). Non-invasive vagus nerve stimulation (VNS), particularly through auricular stimulation, has been shown to modulate autonomic balance by reducing sympathetic activity, enhancing cardiac baroreflex sensitivity, and improving parasympathetic tone (3,4).
In the context of athletic performance, the autonomic nervous system's role in adaptation to training and recovery is well recognized (5). Post-exercise parasympathetic reactivation is increasingly used as a biomarker for recovery and performance enhancement. Auricular VNS (aVNS), by stimulating afferent auricular branches of the VN, may facilitate recovery by reducing exercise-induced fatigue, pain, and lactate accumulation, while improving parasympathetic activity (3). Importantly, these physiological effects have been observed without significant alterations in heart rate or blood pressure.
Balance training is a known contributor to improved functional performance in athletes, and neuromuscular control is essential for injury prevention and overall athletic capacity (6). Considering the limited research on the effects of aVNS on neuromuscular parameters such as muscle strength and balance response in non-elite athletic populations, this study aims to provide evidence on the efficacy of aVNS in this context.
This study is designed as a non-randomized controlled trial. Thirty non-elite athletes aged 18-35 years, who have been physically active for at least three months and currently exercise 2-5 days per week (averaging 3.2 hours per week), will be recruited. Eligible participants must have a BMI between 18.5 and 25 kg/m² and provide informed consent. Individuals with conditions affecting the inner or outer ear or BMI values outside the specified range will be excluded.
The intervention group will receive a single session of bilateral aVNS using a biphasic, asymmetric waveform at a frequency of 25 Hz, pulse width of 300 microseconds, applied continuously for 20 minutes. The post-intervention follow-up period will last 30 minutes (3).
Assessment Parameters
Demographic and Baseline Characteristics:
Collected via a structured interview, including age, gender, height, weight, weekly exercise volume, and auditory health status.
Balance Assessment:
Balance will be evaluated using the Biodex Balance System, which quantifies postural sway and center of pressure (COP) metrics. Tests will be performed under both eyes-open and eyes-closed conditions, with three trials conducted for each. Lower sway index values indicate better balance performance (7).
Muscle Strength Assessment:
Maximal isometric strength of the quadriceps femoris and hamstring muscles will be measured using a Hand-Held Dynamometer (HHD). For quadriceps testing, participants will be seated with knees flexed to 90°, and the dynamometer placed 1-2 cm above the malleoli. For hamstring assessment, participants will lie prone with knees flexed to 90°. The "make test" method will be used, where the participant applies maximal voluntary contraction against a stationary dynamometer held by the examiner. Each muscle group will be tested three times with 60-second rest intervals, and the average value will be used for analysis (8).
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Vagus nerve stimulation | Experimental | Device: Auricular vagus nerve stimulation (AVNS)Auricular vagus nerve stimulation (AVNS) will be applied to both ears simultaneously, using a biphasic, asymmetric waveform with pulses of 300 microsecond duration and a frequency of 25 Hz, continuously for 20 minutes. The application will be performed in a single session and the follow-up time will be determined as 30 minutes. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- body mass index (BMI) between 18.5-25 kg/m²
- exercising for a total of 3 hours or more per week for at least three months
Key exclusion criteria (1 listed)
- have a chronic musculoskeletal disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Auricular vagus nerve stimulation (AVNS)Auricular vagus nerve stimulation (AVNS) will be applied to both ears simultaneously, using a biphasic, asymmetric waveform with pulses of 300 microsecond duration and a frequency of 25 Hz, continuously for 20 minutes. The application will be performed in a single session and the follow-up time will be determined as 30 minutes. | Device | Vagus nerve stimulation |
Primary outcome
Muscle strenght
Time frame: Baseline and after the vagus stimulation apply
Muscle strength of quadriceps femoris and hamstring muscles will be evaluated by hand dynamometer.
Balance
Time frame: Baseline and after the vagus stimulation apply
Postural sway will be assessed by biodex balance with center of gravity characteristics anterior-posterior and lateral sway with eyes closed and open.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2025.
- Background: PubMed 35068342Peller A, Garib R, Garbe E, Komforti D, Joffe C, Magras A, Trapuzzano A, Stock MS, Dawson NT. Validity and reliability of the NIH Toolbox(R) Standing Balance Test As compared to the Biodex Balance System SD. Physiother Theory Pract. 2023 Apr;39(4):827-833. doi: 10.1080/09593985.2022.2027584. Epub 2022 Jan 23.
- Background: PubMed 26952376Unver B, Bakirhan S, Karatosun V. Does a weight-training exercise programme given to patients four or more years after total knee arthroplasty improve mobility: A randomized controlled trial. Arch Gerontol Geriatr. 2016 May-Jun;64:45-50. doi: 10.1016/j.archger.2016.01.003. Epub 2016 Jan 6.
- Background: PubMed 21395364Hrysomallis C. Balance ability and athletic performance. Sports Med. 2011 Mar 1;41(3):221-32. doi: 10.2165/11538560-000000000-00000.
- Background: PubMed 37974551Hatik SH, Arslan M, Demirbilek O, Ozden AV. The effect of transcutaneous auricular vagus nerve stimulation on cycling ergometry and recovery in healthy young individuals. Brain Behav. 2023 Dec;13(12):e3332. doi: 10.1002/brb3.3332. Epub 2023 Nov 16.
- Background: PubMed 38146234Caliota A, Ozden AV, Ceylan I. Effects of a single session of noninvasive auricular vagus nerve stimulation on sports performance in elite athletes: an open-label randomized controlled trial. Expert Rev Med Devices. 2024 Mar;21(3):231-237. doi: 10.1080/17434440.2023.2299300. Epub 2023 Dec 30.
- Background: PubMed 26364692Yuan H, Silberstein SD. Vagus Nerve and Vagus Nerve Stimulation, a Comprehensive Review: Part I. Headache. 2016 Jan;56(1):71-8. doi: 10.1111/head.12647. Epub 2015 Sep 14.
- Background: PubMed 35051375Prescott SL, Liberles SD. Internal senses of the vagus nerve. Neuron. 2022 Feb 16;110(4):579-599. doi: 10.1016/j.neuron.2021.12.020. Epub 2022 Jan 19.
- Individual participant dataSharing planned: Undecided
Related trials for Vagus Nerve Stimulations
Recruiting
Biomarkers of Paired VNS
Stroke, Ischemic
Recruiting
Effects of Vagus Nerve Stimulation on Temporomandibular Disorders.
TMD, Temporomandibular Disorders (TMDs)
Recruiting
taVNS in Infants Severe Dysphagia
Dysphagia, Swallowing Disorders
Recruiting
Transcutaneous Auricular Vagus Nerve Stimulation Device in CKD Population
Chronic Kidney Disease
Recruiting
Identification of Biomarkers for Vagus Nerve Stimulation in Patients With Refractory Epilepsy
Refractory Epilepsy
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Auricular vagus nerve stimulation (AVNS) in people with Vagus Nerve Stimulations and Muscle Strength, run by Bahçeşehir University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Muscle strenght (time frame: Baseline and after the vagus stimulation apply). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06985043, which also lists 7 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2025.