The effect of preexercise meal composition on substrate oxidation during incremental cycling to exhaustion in recreationally active adults: randomized parallel pilot trial
Abstract
Purpose
The purpose of this study is to evaluate the effect of three different preexercise meals: high-carbohydrate, low-glycemic index (LGI), high-carbohydrate, high-GI (HGI) and low-carbohydrate high fat (LCHO) on substrate oxidation during an incremental cycling test (ICT) in recreationally active adults.
Design/methodology/approach
This was a parallel, randomized study in which participants ingested one of three meals (LGI, HGI or LCHO) 3 h prior to exercise testing. Testing included ICT to exhaustion with continuous ergospirometry measurement.
Findings
Fat oxidation rate was significantly higher in LCHO compared to HGI (p = 0.039). Carbohydrate contribution to energy production was significantly lower and fat contribution higher in LCHO compared to HGI (p = 0.034). Fat-to-carbohydrates crossover point was achieved at significantly higher heart rate in LCHO group compared to LGI and HGI (p = 0.046 and p = 0.049, respectively). Peak fat oxidation occurred significantly later during exercises in LCHO group compared to HGI (p = 0.025). In conclusion, LCHO meal results in a higher fat oxidation, reduced carbohydrates contribution-to-energy production, delayed peak fat oxidation point and altered fat-to-carbohydrates crossover dynamics. There are no differences in substrate oxidation between high-carbohydrate preexercise meals that differ only in GI.
Originality/value
To the best of the authors’ knowledge, this is the first study to compare the acute effect of both the amount of carbohydrates and the GI in a preexercise meal on substrate utilization during ICT.
Keywords
Acknowledgements
Funding: The study was funded by internal sources of the Department of Human Nutrition and Dietetics, Poznan University of Life Sciences and Department of Physiology and Biochemistry, Poznan University of Physical Education.
Compliance with ethical standards: The study protocol underwent review and approval by the local institutional review board (Bioethics Committee at Poznan University of Medical Sciences, reference number: 939/16). In accordance with the Declaration of Helsinki, all participants provided informed consents.
Citation
Zawieja, E., Podgórski, T., Zanchi, N.E. and Durkalec-Michalski, K. (2024), "The effect of preexercise meal composition on substrate oxidation during incremental cycling to exhaustion in recreationally active adults: randomized parallel pilot trial", Nutrition & Food Science, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/NFS-08-2024-0265
Publisher
:Emerald Publishing Limited
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