ISENC: International Sports and Exercise Nutrition Conference Newcastle 2016.
Held in Newcastle upon Tyne December 2016 where I presented my Thesis titled:
The International Journal of Sport Nutrition and Exercise Metabolism (IJSNEM) publishes original scientific investigations and scholarly reviews offering new insights into sport nutrition and exercise metabolism, as well as articles focusing on the application of the principles of biochemistry, physiology, and nutrition to sport and exercise.
Click the link below for The Human Kinetics Journal - International Sports and Exercise Nutrition Conference for the abstracts of each journal article in the International Journal of Sport Nutrition and Exercise Metabolism, 2017, 27, S1 - S20.
Byrne, G. , Murad, L. , Stewert, D.
Physiological effects of acute intake of Irish blackcurrant juice during an incremental cycling test in endurance athletes.
The polyphenol compound anthocyanin present in blackcurrant juice (BC) has been found to elicit positive biological action in terms of cardiovascular and metabolic functions. Supplementation of BC may also enhance aerobic exercise performance. With seven days intake of New Zealand blackcurrant powder, a shift of the lactate curve was observed with 4 mmol /lof lactate obtained at higher power output. Acute effects of BC intake on responses during exercise are not fully known. Therefore, the actions of an acute intake of anthocyanins in BC may affect exercise performance benefits in relation to blood lactate, power output, heart rate and time in a standard exercise ramp test. This study set out to ascertain if acute supplementation of a high dose of BC affects responses during an incremental cycling protocol in healthy trained cyclists. The primary purpose of this study was to examine whether a single dose of BC ingested prior to the endurance ramp protocol may affect parameters at a blood lactate (BLa) value of 4mmol/l. The design was a randomized controlled trial using blinding. The study sample was 14 male endurance athlete: height (175±7 cm), weight (71.3 ± 8.9 kg), age (36±6 y). Each subject was blinded and received either a BC or placebo (PLa) juice in 500ml liquid with 300ml of BC containing 105mg of anthocyanin or coloured water 2h prior to testing. The endurance ramp protocol test to 4mmol/l BLa was performed on a Watt bike ergometer starting at 125W with 3 min stages of 25W increments to reach 4mmol/l BLa. Power, time and heart rate were measured at each 3 min interval; all metrics were recorded, compared using t- test and analysed on Graphpad Prism statistical software (P<0.05). There was difference after a high dose of BC in power (BC: 227±5 W (n 6), PLa: 222±5 W (n=6), P=0.54), time (BC: 15.3±0.6 min (n=6), PLa: 14.2±0.9 min(n=6), P=0.37) and heart rate (BC: 155±2beats/min (n=6), PLa: 160±3beats/min (n=6), P=0.29) to reach a blood lactate value of 4 mmol/l. A single dose of BC had no effect on power, time or heart rate in an endurance ramp protocol test to reach a blood lactate value of 4mmol/l. Future studies may examine how many days intake of blackcurrant are required to observe changes in physiological and performance responses during exercise testing in trained endurance athletes.
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https://www.sponet.de/sponet/Record/4043509
World Congress of Science & Cycling, July 2014, Leeds
Organised by leading sport scientists at the University of Kent, under the banner of the World Commission of Science and Sports, the World Congress of Cycling Science 2014 coincided with the Grand Depart of the Tour de France in Leeds 2014. My Thesis was presented titled;
The effect of beetroot juice dosage on high intensity intermittent cycling performance - published in Journal of Science and Cycling (JSC) Vol 3, No 2 (2014).
This journal publishes research articles, reviews, brief communications and letters in all areas of Cycling or Triathlon sciences. The journal aims to provide the most complete and reliable source of information on current developments in the field. The emphasis will be on publishing quality articles.
The effect of beetroot juice dosage on high intensity intermittent cycling performance
Authors
G. Byrne B. Wardrop A. Storey
Abstract
Background: Resynthesis of creatine phosphate (PCr) and intramuscular pH, which influences glycolytic rate, are dependent on skeletal muscle blood flow (Sahlin et al., 1979: Scandinavian Journal of Clinical and Laboratory Investigation 39(6):551-8; Sutton et al., 1981: Clinical Science 61(3):331-8). Skeletal muscle blood flow during exercise has been shown to be enhanced following supplementation with nitrate-rich beetroot juice (BJ) through a nitrate-nitrite-nitric oxide-mediated mechanism (Ferguson et al., 2013: Journal of Physiology 591(Pt 2):547-57).
Purpose: The purpose of this study was to determine if acute supplementation with BJ enhanced subsequent high intensity intermittent cycling performance and to investigate if performance gains could be influenced by varying BJ dosage.
Methods: In a randomised control trial with a repeated-measures crossover design, 2 hours after consumption of low dose (250ml), high dose (500ml) of a commercially available BJ or nothing, 8 active young males (24 ± 8.5yrs) completed three 30s Wingate anaerobic tests (WAnT) on a Monark 894E interspersed with 3 minutes active cycling recovery at low intensity. The three trials were separated by a 7-day washout period for each participant. Peak power (PP), mean power (MP) and fatigue index (FI) were recorded for each WAnT and were compared using a two-way repeated measures ANOVA.
Results: MP declined successively in the second and third WAnT in each trial (p<0.05), however no changes were observed in PP or FI in any trial. No significant differences in MP, PP or FI at any time point were observed across the three treatment arms.
Discussion: The maintenance of PP across successive WAnT indicates resynthesis of PCr during recovery periods, but the decline of MP possibly suggests a progressive decline in total PCr availability and/or a decline in intramuscular pH at each stage. Lack of a supplementation effect on measures of anaerobic power suggests BJ neither expedites PCr resynthesis nor restores intramuscular pH through either a skeletal muscle blood flow or other mechanism.
Conclusion: Acute supplementation with BJ has no beneficial effect, even with high dosage, on high intensity intermittent cycling performance.