Affordable Access

deepdyve-link
Publisher Website

Acute p-synephrine ingestion increases whole-body fat oxidation during 1-h of cycling at Fatmax.

Authors
  • Gutiérrez-Hellín, Jorge1, 2
  • Ruiz-Moreno, Carlos1
  • Del Coso, Juan3
  • 1 Exercise Physiology Laboratory, Camilo José Cela University, Madrid, Spain. , (Spain)
  • 2 Faculty of Health Sciences, Universidad Francisco de Vitoria, Pozuelo, Spain. , (Spain)
  • 3 Centre for Sport Studies, Universidad Rey Juan Carlos, Fuenlabrada, Spain. [email protected] , (Spain)
Type
Published Article
Journal
European Journal of Nutrition
Publisher
Springer-Verlag
Publication Date
Nov 05, 2019
Identifiers
DOI: 10.1007/s00394-019-02101-6
PMID: 31691018
Source
Medline
Keywords
Language
English
License
Unknown

Abstract

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. 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. 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. Acute ingestion of p-synephrine augments fat oxidation during prolonged and constant-intensity exercise.

Report this publication

Statistics

Seen <100 times