Effects of transcranial direct current stimulation and acetazolamide consumption on exercise and cognitive performance, and physiological and perceptual responses of mountaineers in simulated altitude

Determining the separate and combined effects of acetazolamide administration and transcranial direct current stimulation (tDCS) on athletic and cognitive performance, as well as physiological and perceptual responses, in mountaineers under simulated high-altitude conditions

Within-subject (crossover), double-blind design: 1) Acetazolamide + M1 stimulation 2) Acetazolamide + DLPFC stimulation 3) Acetazolamide + sham stimulation 4) Placebo + M1 stimulation 5) Placebo + DLPFC stimulation 6) Placebo + sham stimulation

The laboratory of the Faculty of Physical Education and Sport Sciences. Both the participant and the researcher were blinded.

Inclusion criteria: male participants aged 18–44 years old; active mountaineers (history of ascents to altitudes above 4,000 m); regular aerobic training at least three sessions per week (including mountaineering and hiking); previous history of acute mountain sickness (AMS) during overnight stays at altitudes above 3,000 m; medical clearance certifying no contraindication for participation in the exercise training program. Exclusion criteria: overnight stay at altitudes above 2,700 m within two weeks prior to the start of the study; use of acetazolamide within two weeks prior to the start of the study; allergy to acetazolamide or sulfonamides; history of any cardiovascular, pulmonary, or metabolic disease; presence of any implanted medical devices or pacemakers.

Normobaric Hypoxia; Acetazolamide; tDCS

Time to exhaustion; EMG amplitude; choice reaction time; Continuous Performance Test; Stroop word–color test; perceived exertion; arterial oxygen saturation; pleasure, arousal; balance

To randomize the order in which participants are exposed to the four different conditions, the Latin square method will be used. First, using the website www.random.org, each participant will be randomly assigned a number between 1 and 12 as an identification code. Then, the English letters A, B, C, D, E, and F will be assigned to the six intervention conditions, and a 6×6 Latin square will be created. After generating the Latin square, participants numbered 1 and 2 will follow the sequence of the first row, participants numbered 3 and 4 will follow the sequence of the second row, participants numbered 5 and 6 will follow the sequence of the third row, participants numbered 7 and 8 will follow the sequence of the fourth row, participants numbered 9 and 10 will follow the sequence of the fifth row, and participants numbered 11 and 12 will follow the sequence of the sixth row

The present study will be conducted in a double-blind manner. Neither the participants nor the principal investigator will be aware of the type of stimulation administered in each session, and this information will be accessible only to an individual outside the research team until the completion of the study. To conceal the stimulation order from the principal investigator, all procedures related to the random determination of the stimulation sequence for each participant will be carried out by the same individual outside the research team. Furthermore, to conceal the type of stimulation in each session from the participants, the tDCS device will be hidden from their view using a cover, and the principal investigator will not be present in the laboratory during electrode placement or at the end of the 20-minute session when the electrodes are removed.

Title: Psychological and Physiological Study Data Details: Includes questionnaire scores, exercise performance, and physiological indices of participants.

The data will be available to qualified researchers after completion of the study and

Access will be granted to qualified researchers and individuals with ethical approval

The data will be used solely for research and scientific purposes, and access is conditional on compliance with ethical regulations and maintaining participant confidentiality.

To access the data, researchers may contact the corresponding author of the study.

Requests for data must be sent to the corresponding author. After reviewing ethical compliance and researcher qualifications, the data will be provided in a de-identified format.

All data will be stored and shared in accordance with data protection regulations and research ethics principles.