![Sample our Sports and Leisure journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5949/TOC-Subject-Sample-2021-Sports-Leisure.jpg"})
Abstract
Background
Whilst exogenous carbohydrate oxidation (CHOEXO) is influenced by mono- and disaccharide combinations, debate exists whether such beverages enhance fluid delivery and exercise performance. Therefore, this study aimed to ascertain CHOEXO, fluid delivery and performance times of a commercially available maltodextrin/ fructose beverage in comparison to an isocaloric maltodextrin beverage and placebo.
Methods
Fourteen club level cyclists (age: 31.79 ± 10.02 years; height: 1.79 ± 0.06 m; weight: 73.69 ± 9.24 kg; VO2max: 60.38 ± 9.36 mL · kg·-1 min-1) performed three trials involving 2.5 hours continuous exercise at 50% maximum power output (Wmax: 176.71 ± 25.92 W) followed by a 60 km cycling performance test. Throughout each trial, athletes were randomly assigned, in a double-blind manner, either: (1) 1.1 g · min-1 maltodextrin + 0.6 g · min-1 fructose (MD + F), (2) 1.7 g · min-1 of maltodextrin (MD) or (3) flavoured water (P). In addition, the test beverage at 60 minutes contained 5.0 g of deuterium oxide (2H2O) to assess quantification of fluid delivery. Expired air samples were analysed for CHOEXO according to the 13C/12C ratio method using gas chromatography continuous flow isotope ratio mass spectrometry.
Results
Peak CHOEXO was significantly greater in the final 30 minutes of submaximal exercise with MD + F and MD compared to P (1.45 ± 0.09 g · min-1, 1.07 ± 0.03 g · min-1and 0.00 ± 0.01 g · min-1 respectively, P < 0.0001), and significantly greater for MD + F compared to MD (P = 0.005). The overall appearance of 2H2O in plasma was significantly greater in both P and MD + F compared to MD (100.27 ± 3.57 ppm, 92.57 ± 2.94 ppm and 78.18 ± 4.07 ppm respectively, P < 0.003). There was no significant difference in fluid delivery between P and MD + F (P = 0.078). Performance times significantly improved with MD + F compared with both MD (by 7 min 22 s ± 1 min 56 s, or 7.2%) and P (by 6 min 35 s ± 2 min 33 s, or 6.5%, P < 0.05) over 60 km.
Conclusions
A commercially available maltodextrin-fructose beverage improves CHOEXO and fluid delivery, which may benefit individuals during sustained moderate intensity exercise. The greater CHOEXO observed when consuming a maltodextrin-fructose beverage may support improved performance times.
Electronic supplementary material
The online version of this article (doi:10.1186/1550-2783-11-8) contains supplementary material, which is available to authorized users.
Michael D Tarpey, Lindsy S Kass, Richard J Tarpey and Michael G Roberts contributed equally to this work.
Electronic supplementary material
The online version of this article (doi:10.1186/1550-2783-11-8) contains supplementary material, which is available to authorized users.
Michael D Tarpey, Lindsy S Kass, Richard J Tarpey and Michael G Roberts contributed equally to this work.
Acknowledgements
The authors wish to acknowledge High5 Ltd. for providing the support and funding to undertake this study. All products used for test beverages were supplied by High 5 Ltd. independently of the investigatory team. The authors also wish to acknowledge the support and external collaboration with Iso-Analytical Ltd., for independent assessment of expired air and blood samples.
Competing interests
Research funding and product supply to support this study was received from High 5 Ltd. All data was collected, analysed and reported by the investigatory team fully independently of the company.
Authors’ contributions
All authors were involved in the study. JDR was the principal researcher, involved with liaison with the company, participant assessment, data collection, statistical analysis and manuscript generation; MDT was co-researcher involved with cohort organization, data collection and blood analyses, confirmation of statistical analyses, and manuscript editing; LSK was involved with monitoring of data collection including collation of performance data, and test beverage administration, as well as manuscript editing; RJT was involved with data collection and analysis; MGR was involved in quality control, data collection, and technical accuracy in preparation of the manuscript. All authors read and approved the final manuscript.