Assessing a commercially available sports drink on exogenous carbohydrate oxidation, fluid delivery and sustained exercise performance

Roberts, Justin D. and Tarpey, Michael D. and Kass, Lindsy S. and Tarpey, Richard J. and Roberts, Michael G. (2014) Assessing a commercially available sports drink on exogenous carbohydrate oxidation, fluid delivery and sustained exercise performance. Journal of the International Society of Sports Nutrition, 11 (8). ISSN 1550-2783

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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.

Item Type: Journal Article
Keywords: fructose, maltodextrin, exogenous carbohydrate oxidation, fluid delivery, performance
Faculty: ARCHIVED Faculty of Science & Technology (until September 2018)
Depositing User: Repository Admin
Date Deposited: 25 May 2016 08:53
Last Modified: 09 Sep 2021 19:01

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