The effects of New Zealand Blackcurrant on critical velocity and speed tolerable-duration relationship during running

[摘要] Background: Supplement intake is used to support training practice and performance enhancement. Performance enhancing techniques include anything from a training plan and a good nutrition to supplement consumption and legal substances. Research is now focused on the functional food ingredients of these ergogenic aids or also called superfoods. Blackcurrant (BC) is considered as one of the superfoods and there is research going on in the literature examining its effects on both health and performance. In order to maximize training at severe intensity exercise domain, the currently new concept of Critical Velocity (CV) could be used from which greater number of benefits may occur.Aim: (i) To test the reproducibility of CV and speed-tolerable duration in runners and non-runners (controls) and (ii) examine the effects of New Zealand Blackcurrant (NZBC) based on these two parameters. Methods: In the first part of the study, eight (N=8) runners and nine (N=9) controls volunteered for participation and performed two series of exhaustive tests. For CV and D’ determination, tolerable-duration (V-t) and Velocity – 1/time (inverse of time) relationships were plotted. In part 2, the Blackcurrant (BC) supplementation intervention study, seven (N=7) young, healthy, recreationally active males participated. Testing comprised of resting measurements (ventilation hood, Bodpod, and resting lactate), Incremental Exercise Test (IET) and four Constant Load Tests which were randomized over two phases either on BC or Placebo (PLA) supplementation.Results and Conclusions: The reproducibility tests showed that there was no statistical difference for Maximal Oxygen Uptake (V ̇O2 max) and Maximal Heart Rate (HR max) during the Constant Load Trials and IET for both runners and controls. This confirms that exhaustion was always reached in all tests. Mean CV as well as distance covered (D’) were not different for the runners between the test and retest. However, there was a difference in these parameters between the test and retest for the controls. This supports validation of the hypothesis that CV and D’ are reproducible for the runners and not for the non-runners.For the BC supplementation study, mean values for CV and D’ showed no discernible difference between BC and PLA subjects. Subjects under BC supplementation produced approximately the same CV value when compared to the ones under PLA. This implies that BC has little effect on CV. However, when looking at individual results, 60% of the subjects (4 out of 7) showed an increase in D’ under the effect of BC, even up to 41%. Two subjects showed a decrease of the order of 10%. This implies that BC enhancement may improve D’ but more specific studies are proposed to decipher the factors. The above are supported by measurements of Heart Rate (HR), Oxygen uptake (V ̇O2), Energy Expenditure (EE), Fat oxidation (Fat), Carbohydrate oxidation (CHO) and Running Economy (RE) all of which showed small or no effect with intervention.

[发布机构] University:University of Glasgow;Department:Institute of Cardiovascular and Medical Sciences

[关键词] Exercise, supplement intake, running.