Nitrate (${\mathrm{NO}}_3^{-}$) has properties that can improve muscle function, leading to improvements in metabolic cost of exercise as well as enhance force production. Gymnastics is a whole-body sport, involving events that demand a high level of strength and fatigue resistance. However, the effect of ${\mathrm{NO}}_3^{-}$ supplementation on both upper- and lower-body function in gymnasts is unknown. This study examined the effect of acute beetroot juice (BRJ) supplementation on isokinetic strength and endurance of the upper- and lower-body in highly trained international-level male gymnasts. In a double-blind, randomized crossover design, 10 international-level male gymnasts completed two acute supplementation periods, consuming either 2 × 70 ml ${\mathrm{NO}}_3^{-}$-rich (∼12.8 mmol/L of ${\mathrm{NO}}_3^{-}$) or ${\mathrm{NO}}_3^{-}$-depleted (PLA) BRJ. Maximal strength of the upper-leg and upper-arm at 60°/s, 120°/s, 180°/s, and 300°/s, and muscular endurance (50 repeated isokinetic contractions at 180°/s) were assessed. Plasma ${\mathrm{NO}}_3^{-}$ (BRJ: 663 ± 164 μM, PLA: 89 ± 48 μM) and nitrite (${\mathrm{NO}}_2^{-}$) concentrations (BRJ: 410 ± 137 nmol/L, PLA: 125 ± 36 nmol/L) were elevated following BRJ compared to PLA (both p < .001). Maximal strength of knee and elbow extensors and flexors did not differ between supplements (p > .05 for all velocities). Similarly, fatigue index of knee and elbow extension and flexion was not different between supplements (all p > .05). Acute BRJ supplementation, containing ∼12.8 mmol/L of ${\mathrm{NO}}_3^{-}$, increased plasma ${\mathrm{NO}}_3^{-}$ and ${\mathrm{NO}}_2^{-}$ concentrations, but did not enhance isokinetic strength or fatigue resistance of either upper or lower extremities in international-level male gymnasts.