a-tDCS Combined With Aerobic Exercise in Healthy Individuals

Study Overview
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Brief Summary
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The purpose of this study is to assess the effects on the exercise performance of anodal transcranial direct current stimulation combined with aerobic exercise in healthy individuals.

Detailed Description
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Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method that has become increasingly popular in recent years. tDCS shows promising improvements for the motor performance of healthy individuals as well as pathological conditions. Moreover, it is frequently preferred because of its safety advantage, high tolerability as well as being cheap, portable and easily applicable. Studies have shown that tDCS can modulate the excitability of both cortical and subcortical brain regions. In recent years, there have been scientific studies investigating the effects of tDCS on improving physical performance in healthy individuals, but these studies are limited in number, their results are conflicted and as far as the investigators know there is no study that combines tDCS with exercise. Moreover, although the mechanisms of tDCS on physical performance are largely unknown, some tDCS devices are open to public usage and a large number of professional athletes have reported using tDCS during their training programs. Therefore, studies are needed to demonstrate the effects of tDCS which combined with exercise on performance. The aim of this study was to investigate the effects of anodal transcranial direct current stimulation combined with aerobic exercise on physical performance in healthy individuals.

Official Title
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The Effect of Anodal Transcranial Direct Current Stimulation Combined With Aerobic Exercise on Performance in Healthy Individuals

Conditions
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Healthy

Intervention / Treatment
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* Device: Real tDCS
* Device: Sham tDCS
* Other: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy subject No use of any ergogenic substance in one year No history of active exercise training in last 6 months Exclusion Criteria: Pacemaker Intracerebral metallic implant Using dietary supplementation or medication potentially affecting the CNS Musculoskeletal injury within the past 6 weeks Lower extremity pain above 3 or more according to numeric pain scale History of epilepsy or convulsive crisis

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Real tDCS and Exercise<br>tDCS (tDCS - TCT Research Limited, Hong Kong) / Exercise Group in which will receive the active intervention of aerobic exercise training and active tDCS intervention at the same time. | Device: Real tDCS<br>* Real tDCS (TCT Research Limited, Hong Kong); 3 times a week on alternate days for consecutive 6 weeks. The active session of tDCS will consist in applying anodal stimulation over left M1 (C3 according to the 10-20 international EEG placement) and the cathodal stimulation over right supraorbital area (Fp2 according to the 10-20 international EEG placement), and to inject 2 mA for 20 minutes through sponge electrodes (35 cm²) placed on the scalp.<br>Other: Exercise<br>* The Exercise intervention will include only aerobic exercise 3 times a week on alternate days for consecutive 6 weeks. The program will last 20 minutes.<br>|
| Sham Comparator: Sham tDCS and Exercise<br>Sham tDCS (tDCS - TCT Research Limited, Hong Kong) / Exercise Group in which will receive the active intervention of aerobic exercise training and sham tDCS intervention at the same time. | Device: Sham tDCS<br>* Sham current (TCT Research Limited, Hong Kong); 3 times a week on alternate days for consecutive 6 weeks. The sham tDCS will use the same montage and device but direct current will only be injected for 30 seconds, with a ramp-up and ramp-down 15 seconds period, to mimic the somatosensory effects of active tDCS.<br>Other: Exercise<br>* The Exercise intervention will include only aerobic exercise 3 times a week on alternate days for consecutive 6 weeks. The program will last 20 minutes.<br>|
| Other: Exercise<br>Exercise group in which will receive the active intervention of aerobic exercise training no tDCS intervention. | Other: Exercise<br>* The Exercise intervention will include only aerobic exercise 3 times a week on alternate days for consecutive 6 weeks. The program will last 20 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of tDCS combined with aerobic exercise on exercise performance in healthy individuals. | The performance will be evaluated by measuring the maximal consumption of oxygen (VO2max). VO2max will be assessed continuously during the time to exhaustion trial using a gas analyzer | 2 months | 
| Effect of tDCS combined with aerobic exercise on ratings of perceived exertion (RPE) in healthy individuals. | RPE will be assessed continuously (every 3 minutes) during the time to exhaustion trial using the Borg rating of perceived exertion scale (RPE scale). The Borg RPE scale is a quantitative measure of perceived exertion during physical activity. The scale starts with no feeling of exertion, which rates a 6, and ends with very, very hard, which rates a 20. Moderate activities register 11 to 14 on the Borg scale (fairly light to somewhat hard), while vigorous activities usually rate a 15 or higher (hard to very, very hard). | 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effect of tDCS combined with aerobic exercise on isokinetic muscle strength in healthy individuals. | The isokinetic muscle strength of knee extensors of the dominant leg will be evaluated by using Biodex System 3 isokinetic dynamometer (Biodex Medical Systems, Shirley, NY, USA) | 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Transcranial Direct Current Stimulation, Aerobic Exercise, Performance