• The effects of acute beetroot juice supplementation on the physiological responses during a rugby league match simulation protocol and recovery

      Highton, Jamie M.; Walker, Casey (University of Chester, 2014-09)
      The purpose of this investigation was to examine the physiological effects of acute BR supplementation on rugby league specific intermittent running performance, while also examining the effects of further supplementation on recovery from EIMD. It was hypothesized that BR supplementation would lead to improved intermittent performance and promote recovery from a rugby league match simulation protocol (RLMSP). An experimental, randomized, independent groups design was adopted, including one control group (n = 6) and one experimental group (n = 6). A 70 mL beetroot juice drink (BR) (~6.5 mMol nitrate; 697.9 umol total antioxidant capacity) or control beverage was consumed 2.5 h prior to RLMSP performance. Participants were then required to ingest further beverages, twice a day, separated by 6-8 h for 48 h following the RLMSP. A 2-way (group [2] x time [4]) analysis of variance, independent and paired sample t-tests were conducted. Relative peak sprint speed was maintained in quartile 4 of the RLMSP in the BR group (p>0.05). There was no significant difference between groups for mean speed and high speed running (p>0.05). Blood glucose significantly decreased (p<0.05) in the BR group and not the control. No differences were found for oxygen consumption, blood lactate, heart rate and RPE (p>0.05). BR attenuated EIMD and promoted recovery from the RLMSP evidenced by attenuated CK accumulation, maintained neuromuscular function and a reduced increase in perceived muscular soreness (p<0.05). The findings of this study suggest that acute BR supplementation may enhance intermittent performance and attenuate EIMD following rugby league specific exercise.