UNLABELLED: Muscle-shortening velocity and hence power have been shown to increase in the presence of nitric oxide (NO). NO availability increases after consuming nitrate (NO). Ingestion of NOrich beetroot juice (BRJ) has increased muscle power in untrained adults. 3 3 --
PURPOSE: This study determined whether NOsupplementation could acutely enhance maximal power in trained athletes. 3 -
METHODS: In this double-blind, crossover study, 13 trained athletes performed maximal inertial-load cycling trials (3-4 s) immediately before (PRE) and after (POST) consuming either NOrich (NO3) or NOdepleted (PLA) BRJ to assess acute changes (ie, within the same day) in maximal power (P) and optimal pedaling rate (RPM). Participants also performed maximal isokinetic cycling (30 s) to assess performance differences after supplementation. 3 3MAX opt --
RESULTS: 2 x 2 repeated-measures ANOVA indicated a greater increase in Pfrom PRE to POST NO3 (PRE 1160 ± 301 W to POST 1229 ± 317 W) than with PLA (PRE 1191 ± 298 W to POST 1213 ± 300 W) (P = .009; η= 0.45). A paired t-test verified a greater relative change in Pafter NO3 (6.0% ± 2.6%) than with PLA (2.0% ± 3.8%) (P = .014; d = 1.21). RPMremained unchanged from PRE (123 ± 14 rpm) to POST PLA (122 ± 14 rpm) but increased from PRE (120 ± 14 rpm) to POST NO3 (127 ± 13 rpm) (P = .043; η= 0.30). There was no relative change in RPMafter PLA (-0.3% ± 4.1%), but there was an increase after NO3 (6.5% ± 11.4%) (P = .049; d = 0.79). No differences were observed between the 30-s isokinetic trials. MAX p MAX opt p opt2 2
CONCLUSIONS: Acute NOsupplementation can enhance maximal muscle power in trained athletes. These findings may particularly benefit power-sport athletes who perform brief explosive actions. 3 -
