NUTRITION
IN TOP ATHLETES
INFLUENCE
OF DARK CHOCOLATE
ADMINISTRATION ON URIC ACID, LIVER ENZYMES, LACTATE, GLUCOSE AND
TRIGLYCERIDES CHANGES INDUCED BY SUBMAXIMAL EXERCISE IN ATHLETES
T.
Djarova1,
L. Andreeva2, D. Stefanova2,
G. Mateev2, A. Basson1, S. Tzvetkov2,
L. Kamenov2
1 University of Zululand,
Department of Biochemistry and Microbiology, KwaDlangezwa, South
Africa,
2 National Sports Academy, ,
Sofia, Bulgaria
Introduction.
Exercise can produce an imbalance between reactive oxygen species (ROS)
and the innate antioxidant defense system resulting in oxidative
stress. Considerable interest into the outcomes of antioxidant
administration was reported. Dark chocolate is rich of flavinoids
excreting positive cardiovascular and metabolic effects.
Materials/Methods.
A
randomised study of two periods of 10 days (control and administration
of 50 grams dark chocolate daily) was carried out with eleven
competitive swimmers. Each subject took part of two trials of 15
min submaximal exercise on bicycle ergometer consisting of
two bouts of 10 min at intensity 60% VO2max and 5 min at
90%VO2max conducted without an interval to induce oxidative
stress.
Results.
Uric acid after performing pre-administration submaximal exercise was
elevated by 11.7% (p<0.05) at the end of control period but
dropped by 10.9% in response to 10 days of chocolate intake. Blood
lactate increased immediately following the submaximal tests up to 6.6
mmol/l and 6.1 mmol/l respectively. Lactate was significantly lower
after the dark chocolate treatment. Following submaximal tests
pre-administration glucose was elevated to 5.65 mmol/l whereas post
chocolate administration glucose levels were reduced
significantly. Liver enzymes changes were found within the upper
reference range. Post chocolate administration glucose levels were
slightly reduced. Aspartate-aminotransferase levels were raised by
14.8% after both tests. No changes in γ-aminotransferase,
triglycerides and cholesterol were found.
Conclusion. Dark
chocolate administration might modulate and benefit metabolic changes
under exercise-induced oxidative stress by reducing ROS production,
increasing insulin sensitivity and mobilising liver glutathione to
supply muscle tissue.
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