Protocol summary
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Study aim
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The study aims to compare the effects of tDCS and tPCS on endurance performance, Stroop color-word test results, choice reaction time, perceived exertion, pleasure, arousal level, pain perception, and the countdown task during endurance exercise in physical education students.
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Design
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This study uses a within-subject (crossover) design with randomization of experimental conditions, conducted double-blind with sham control. The order of exposure to the three conditions will be randomized using a Latin square method via www.random.org. A total of 15 participants will be recruited as the appropriate sample size for this study.
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Settings and conduct
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Participants will complete Stroop and choice reaction time tests before and after receiving electrical stimulation and performing an exhaustive cycling task. A one-minute countdown task will be administered at RPE 15. Perceptual–physiological variables (pain, pleasure, arousal, RPE, and heart rate) will be assessed every three minutes during exercise.
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Participants/Inclusion and exclusion criteria
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Inclusion Criteria: Age 18–29 years; male physical education students at Razi University, third semester or higher; body mass index (BMI) 18.5–24.9 kg/m²; right-handed.
Exclusion Criteria: Presence of any cardiovascular, pulmonary, or metabolic disease; history of seizures, epilepsy, or other neurological disorders; presence of implanted medical devices or pacemakers; use of tobacco or alcohol; color blindness or other visual impairments.
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Intervention groups
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Group 1: Received tDCS stimulation in the DLPFC region;
Group 2: Received tPCS stimulation in the DLPFC region;
Group 3 (or placebo group): Received sham stimulation.
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Main outcome variables
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Endurance performance, Stroop test, reaction time, countdown task, heart rate, rating of perceived exertion, pleasure, and arousal.
General information
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Reason for update
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The endurance testing protocol was modified from a 15-kilometer time-trial to a cycling endurance time to exhaustion test.
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Acronym
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IRCT registration information
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IRCT registration number:
IRCT20250812066842N1
Registration date:
2025-08-16, 1404/05/25
Registration timing:
prospective
Last update:
2026-02-08, 1404/11/19
Update count:
1
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Registration date
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2025-08-16, 1404/05/25
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Registrant information
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Recruitment status
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Recruitment complete
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Funding source
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Expected recruitment start date
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2025-09-23, 1404/07/01
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Expected recruitment end date
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2025-11-21, 1404/08/30
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Actual recruitment start date
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empty
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Actual recruitment end date
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empty
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Trial completion date
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empty
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Scientific title
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Comparing the Effects of Transcranial Direct and Pulsed Current Stimulation on Endurance and Cognitive Performance in Physical Education Students
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Public title
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Non-invasive brain stimulation and Endurance function
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Purpose
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Supportive
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Inclusion/Exclusion criteria
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Inclusion criteria:
Age range: 18–29 years
Male physical education students at Razi University, third semester or higher
Body mass index (BMI): 18.5–24.9 kg/m²
Right-handed
Exclusion criteria:
Presence of any cardiovascular, pulmonary, or metabolic disease
History of seizures, epilepsy, or other neurological disorders
Presence of implanted medical devices or pacemakers
Use of tobacco or alcohol
Color blindness or other visual impairments
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Age
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From 18 years old to 29 years old
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Gender
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Male
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Phase
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N/A
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Groups that have been masked
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Sample size
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Target sample size:
15
More than 1 sample in each individual
Number of samples in each individual:
3
In each individual, the following samples/measurements are collected once per condition (tDCS, tPCS, sham), resulting in three sets per participant: Primary outcome 1. Endurance performance: time to exhaustion test on a cycloergometer. 2. Cognitive performance measures: Stroop Color-Word Test results (color, word, and color-word interference scores), reaction time in the choice reaction time test, and countdown task performance (correct responses and accuracy). 3. Physiological and perceptual measures (taken during and/or immediately after exercise): Heart rate, Rating of perceived exertion (RPE), Pleasure rating, Arousal level, Pain perception. Each participant completes all measurements under all three stimulation conditions, with at least 48 hours washout between sessions.
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Randomization (investigator's opinion)
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Randomized
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Randomization description
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To randomize the order in which participants are exposed to the three conditions in this study, a Latin square design will be employed. For this purpose, each participant will first be assigned a unique identification number between 1 and 15 using the website www.random.org. Next, the letters B, A, and C will be assigned to the three intervention conditions, and a Latin square will be constructed. In this configuration, a Latin square with three rows and three columns will be created. Finally, participants numbered 1 to 5 will follow the sequence in the first row, participants numbered 6 to 10 will follow the sequence in the second row, and participants numbered 11 to 15 will follow the sequence in the third row.
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Blinding (investigator's opinion)
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Double blinded
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Blinding description
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Both the participants and the principal investigator will be blinded to the type of stimulation received in each session. This information will remain accessible only to an individual outside the research team until the completion of the study. To maintain blinding of the stimulation order from the principal investigator, all procedures related to the random assignment of stimulation sequences for each participant will be conducted by this external individual. Additionally, to blind participants to the type of stimulation in each session, the tDCS device will be concealed from view using a cover, and the principal investigator will not be present in the laboratory during electrode placement, throughout the 20-minute stimulation period, or during electrode removal.
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Placebo
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Used
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Assignment
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Crossover
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Other design features
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Ethics committees
1
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Ethics committee
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Approval date
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2025-07-02, 1404/04/11
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Ethics committee reference number
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IR.RAZI.REC.1404.019
Health conditions studied
1
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Description of health condition studied
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This study involves healthy male physical education students aged 18–29 years with no cardiovascular, pulmonary, metabolic, neurological, musculoskeletal, or visual disorders. The research does not study a specific disease but examines neuromodulation effects on endurance and cognitive performance in a healthy, physically active population.
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ICD-10 code
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ICD-10 code description
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Primary outcomes
1
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Description
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The primary outcome variable is the endurance performance, specifically measured as the time to exhaustion on ergometer cycling test. This is the main variable expected to change as a result of the interventions (tDCS, tPCS, or sham), and it is the outcome used for calculating the sample size.
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Timepoint
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The primary outcome (endurance performance – time to exhaustion) is measured once in each experimental session, immediately after the application of the intervention (tDCS, tPCS, or sham). There is no multiple follow-up measurements planned — the timepoint is directly after intervention within the same session
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Method of measurement
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The primary outcome variable, namely endurance performance, will be assessed using a cycling test time to exhaustion on a cycle ergometer (Cyclus). During the initial session, participants’ peak power output will be determined by performing an incremental exercise test. In the three main experimental sessions, participants will be required to cycle at 85% of their determined peak power output until exhaustion, and the time to exhaustion will be recorded as the indicator of endurance performance.
Intervention groups
1
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Description
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Intervention group 1: Participants will receive anodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (L-DLPFC) with the anode at F3 and the cathode at AF4, at 2 mA intensity for 20 minutes.
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Category
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Treatment - Devices
2
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Description
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Intervention group 2: Participants will receive anodal transcranial pulsed current stimulation (tPCS) over the left dorsolateral prefrontal cortex (L-DLPFC) with the same electrode placement, at 1.5 mA intensity for 20 minutes.
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Category
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Treatment - Devices
3
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Description
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Control group: Participants will receive sham stimulation with identical electrode placement; however, current will be delivered for only the first 30 seconds and then stopped, mimicking the sensation without providing actual stimulation.
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Category
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Placebo
1
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Sponsor
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Grant name
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Razi University
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Grant code / Reference number
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Is the source of funding the same sponsor organization/entity?
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Yes
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Title of funding source
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Razi University
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Proportion provided by this source
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100
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Public or private sector
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Public
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Domestic or foreign origin
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Domestic
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Category of foreign source of funding
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empty
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Country of origin
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Type of organization providing the funding
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Academic
Sharing plan
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Deidentified Individual Participant Data Set (IPD)
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Undecided - It is not yet known if there will be a plan to make this available
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Study Protocol
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Undecided - It is not yet known if there will be a plan to make this available
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Statistical Analysis Plan
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Not applicable
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Informed Consent Form
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Undecided - It is not yet known if there will be a plan to make this available
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Clinical Study Report
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Undecided - It is not yet known if there will be a plan to make this available
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Analytic Code
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Not applicable
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Data Dictionary
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Not applicable