Selective recovery effects of short-term beetroot juice supplementation after exercise-induced muscle damage in trained female volleyball players

BACKGROUND: Beetroot juice (BRJ) has been proposed as a nutritional aid for recovery from exercise-induced muscle damage (EIMD), but evidence in female team-sport athletes is limited. It also remains unclear whether any benefit extends across functional, pain-related, swelling, and strength outcomes. METHODS: Seventeen female university volleyball players entered a randomized, double-blind, placebo-controlled crossover trial. Four did not complete the second period, so outcomes were analyzed with linear mixed models. After baseline testing, participants performed 200 loaded vertical jumps and consumed BRJ or placebo at 24, 48, and 72 h post-EIMD. Recovery outcomes were countermovement jump (CMJ) height, volleyball-specific agility time, pressure pain threshold, thigh circumference, visual analog scale soreness, and knee isokinetic measures. Holm-adjusted planned contrasts were used. In contrast, agility time and soreness changed over time without clear between-condition differences, while thigh pressure pain threshold, thigh circumference, and low-velocity knee isokinetic outcomes showed no consistent BRJ-related advantage. CONCLUSIONS: Short-term BRJ supplementation was associated with selective rather than generalized recovery benefits after EIMD in trained female volleyball players. The clearest findings were higher CMJ height and calf PPT under BRJ than PLA at 72 h, whereas the remaining outcomes showed no consistent treatment-related differences.