Sara Mansouri, Vahid Tadibi
This study examined whether Ginkgo biloba (GB), used as an adjunct to acetazolamide (Az) for acute mountain sickness (AMS) prevention, affected endurance and cognitive performance under normobaric hypoxia in male mountaineers. This randomized, double-blind, placebo-controlled crossover trial included four sessions and two supplementation phases (GB and placebo) separated by a 1-week washout period. Testing was conducted under normobaric hypoxic conditions (13% O2). Twelve healthy male mountaineers (aged 18-44) with prior high-altitude experience (above 4000 m), a history of AMS, and regular aerobic training were included. Participants received GB (200 mg/day) or a placebo for 5 days, with Az (125 mg, three doses) administered during the final 2 days of each phase. GB supplementation was associated with a significantly longer time to exhaustion (p = 0.019) and lower ratings of perceived exertion (p = 0.020) during treadmill exercise to exhaustion under hypoxia. However, no significant between-condition differences were observed for the Feeling Scale, Felt Arousal Scale, heart rate, or peripheral oxygen saturation during the endurance test. No significant differences were found in choice reaction time or Stroop Color-Word Test outcomes. In conclusion, GB supplementation for 5 days was associated with a longer time to exhaustion under simulated altitude in male mountaineers using Az for AMS prevention, while no significant between-condition differences were observed in cognitive outcomes. The endurance finding is preliminary and should be regarded as exploratory pending confirmation in larger studies. Because Az was administered in both conditions, the effect of GB without Az cannot be determined from this design. Trial Registration: The trial was registered in the Iranian Clinical Trial Registry (www.irct.behdasht.gov.ir, IRCT ID: IRCT20230711058744N1).