RÉSUMÉ
Background: Beetroot juice (BRJ) supplementation has been shown to increase sports performance under hypoxic conditions and to improve athletes' recovery. Objectives: In the present study, we aimed to investigate the effect of acute BRJ supplementation on slalom (SL) run performance and muscle soreness (MS) in Alpine skiers at moderate to high altitudes. Methods: Ten male Alpine skiers received 220 mL of BRJ (8.9 mmol/L nitrate) or placebo (PLA) in 2 sessions with a 7-d wash out interval in a randomized, crossover, PLA-controlled, double-blind study. The 90-s box jump (BJ90), agility hexagonal obstacle jump (Hex Jump), and wall-sit tests were measured before on-hill SL runs in both sessions. After the functional tests, SL run performance was measured by time to complete 2 runs on the SL course; immediately after each SL run, the rating of perceived exertion (RPE) was recorded. In addition, perceived MS was recorded using the visual analog scale at 12, 24, and 48 h after the SL runs. Results: The data were meticulously analyzed using 2-way repeated measures analysis of variance and paired t tests with significance set at P < 0.05. The findings were significant, indicating that compared with PLA, BRJ notably improved wall-sit and BJ90 performances (P < 0.05), while a substantial reduction was observed in RPE, Hex Jump, and MS (P < 0.05). A 1.74% shorter time to complete SL runs was observed in the BRJ group compared with the PLA group; however, there were no significant differences between the PLA and BRJ groups (P > 0.05). Conclusions: These results underscore the potential of BRJ supplementation to enhance sports performance and reduce MS in Alpine skiers under hypoxic conditions.