The effect of altitude on decision making in male rugby union players

Abstract

The body is typically forced to undergo several physiological adaptations when exposed to hypoxia, which can impact physical and cognitive performance. The purpose of this investigation was to study the effects of altitude on cognitive function, specifically decision-making, in male athletes. Seven male rugby union players, at senior club level or above, performed a 15-minute cycling protocol (70-80% HRmax, with 3 × 6-s maximal sprints performed at 5, 10, and 15 min) in normoxia (FIO2 = 0.21%) and hypoxia (FIO2 = 0.15%) in a randomised order. Throughout both trials, a Stroop test was conducted immediately after each sprint to assess decision-making ability. Additionally, heart rate (HR) and rating of perceived exertion (RPE), along with average and peak power output were recorded. Stroop test time (13.3 ± 1.6 vs. 11.8 ± 1.6 s) and oxygen saturation (S_PO₂; 87 ± 2 vs. 97 ± 1%) were impaired in hypoxia compared to normoxia (P = 0.029 and P < 0.01 respectively). All other outcome measures showed no difference between trials. These data confirm that player decision making is negatively affected by altitude, likely due to reduced cerebral oxygenation driving the cognitive impairment. Our findings infer that while rugby union players may be capable of maintaining physiological stability over short durations at altitude, their cognitive ability may be inhibited, resulting in potentially handicapped decision-making during high pressure game situations.