Effects of transcranial direct current stimulation and acetazolamide consumption on the balance of active mountaineers in simulated altitude

Balance is an important factor for the success and health of mountaineers. This study aimed to investigate the separate and combined effects of electrical brain stimulation and acetazolamide on the balance of male mountaineers.

Methods & Materials: 

12 male mountaineers (mean±standard deviasion of age, height, and weight was respectively: 39.8±4.6 years, 177.4±7.8 cm, and 79.1±1.9 kg) participated in this double-blind study. Participants were exposed to six conditions: 1)Acetazolamide-M1 stimulation 2)Acetazolamide-DLPFC stimulation 3)Acetazolamide-sham 4)Placebo-M1 5)Placebo-DLPFC 6)Placebo-sham. In each session, subjects received 20 minutes of brain stimulation, after being exposed to 30 minutes of hypoxia (O2=13%) in a sitting position. Then, participants performed an endurance-exhausting task at 60% of maximal aerobic speed on the treadmill, considering their aerobic endurance. Immediately after the task, the balances of the supporting and nonsupporting legs were measured. The two-way repeated measures ANOVA was used for statistical analysis.

In hypoxic conditions, stimulation of the M1 and DLPFC regions had a significant positive effect on the balance of the supporting leg compared to the sham stimulation conditions (p=0.02 and p=0.03, respectively). However, there was no significant difference between these two types of stimulation. For the nonsupporting leg, no significant difference was observed between the stimulation conditions in different areas. In addition, no significant difference was seen between the use of acetazolamide and sham on the balance of the supporting and nonsupporting legs.

Stimulation of the M1 and DLPFC areas can improve the balance of the supporting leg of mountaineers during high-altitude climbing.