• 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.
    • The effects of exercise on body mass and body composition in postmenopausal breast cancer survivors: A sytematic review

      Fallows, Stephen; Hart, Sarah (University of Chester, 2012-09)
      The aim of this systematic review was to determine the effects of exercise on the body mass (BM), body mass index (BMI), waist circumference (WC), lean body mass (LBM), fat mass (FM), body fat percentage (BF%), bone mineral content (BMC) and bone mineral density (BMD) of postmenopausal breast cancer survivors (BCSs). Records were located via; electronic searches of MEDLINE, Cochrane Library, CINAHL, ProQuest, Sport Discus, PEDro, ZETOC and SCIRUS and handsearches of key journals and book chapters. All searches covered the period from the start of 1989 to the end of June 2012. All identified records were screened against predetermined eligibility criteria. Records that met the full eligibility criteria were included in the final review, and assessed for methodological quality using the Downs and Black Checklist (1998). A total of 5714 records (excluding duplicates) were located; five studies and six groups of exercising postmenopausal BCSs were included in the final review. The differences in the mean change between exercising and control postmenopausal BCSs ranged from 0.70kg to -2.42kg for BM; -0.28kg/m2 to -0.86kg/m2 for BMI; -0.54cm to -3.00cm for WC; 0.1kg to 1.0kg for LBM; 0.5kg to -2.0kg for FM; 0.2% to -2.0% for BF%; -46g/cm to 68g/cm for BMC; 0.000g/cm2 to 0.033g/cm2 for total BMD and 0.004g/cm2 to 0.260g/cm2 for lumbar spine BMD. The findings from individual studies were mixed, however overall exercise had a small favourable effect on the body composition of postmenopausal BCSs (↓BM, ↓BMI, ↓WC, ↑LBM, ↓FM, ↓BF%, ↑BMC and ↑BMD). Further research into the effects of combined aerobic and resistance exercise over longer total exercise durations of 6 to 12 months are warranted. Future studies should include larger sample sizes so that results can be stratified by important confounding factors, without statistical power being compromised.