Acute p-synephrine ingestion increases whole-body fat oxidation during 1-h of cycling at Fatmax.
Loading...
Identifiers
Publication date
2019
Start date of the public exhibition period
End date of the public exhibition period
Advisors
Journal Title
Journal ISSN
Volume Title
Publisher
European Journal of Nutrition
Share
Abstract
Purpose
p-Synephrine, the principal alkaloid of bitter orange (Citrus aurantium), is widely used in dietary supplements for weight loss due to its purported effect of increasing fat oxidation. However, there is a paucity of scientific information about its effectiveness in enhancing fat oxidation during exercise. The aim of this investigation was to determine the effect of an acute dose of p-synephrine on substrate oxidation during prolonged and constant intensity exercise.
Methods
In a double-blind and randomized experiment, 14 healthy subjects performed two acute experimental trials after ingesting either p-synephrine (3 mg kg−1) or a placebo (cellulose). Energy expenditure and fat oxidation rates were continuously measured by indirect calorimetry during 1 h of continuous cycling at Fatmax, the intensity that induces maximal fat oxidation rate.
Results
In comparison to the placebo, energy expenditure during 1 h of cycling remained unchanged with p-synephrine (698 ± 129 vs. 686 ± 123 kcal, P = 0.08). However, p-synephrine increased whole-body fat oxidation (33.6 ± 10.4 vs. 37.3 ± 9.8 g, P < 0.01) while also reducing carbohydrate oxidation (99.5 ± 30.4 vs. 85.0 ± 28.4 g, P < 0.01). However, the magnitude of the shift on substrate oxidation induced by p-synephrine was small.
Conclusion
Acute ingestion of p-synephrine augments fat oxidation during prolonged and constant-intensity exercise.
Doctoral program
Description
Keywords
Nutrition supplement, Exercise, Citrus aurantium, Bitter orange, Maximal fat oxidation