Influence of dark chocolate administration on uric acid, liver enzymes, lactate and glucose changes induced by submaximal exercise in athletes

Objective. To assess the influence of dark chocolate administration on uric acid, liver enzymes, glucose and lactate responses to summaximal exercise test in male swimmers. Subjects. Eleven competitive swimmers from the athletic club Academic, Sofia volunteered for the study. Design. A randomised study of two periods of 10 days (washout period without chocolate and administration period of 50 grams dark chocolate daily) was carried out. Each subject took part in two trials of 15 min submaximal exercise test on a bicycle ergometer consisting of two bouts of 10 min at intensity 60% VO2max and 5 min at 90%VO 2max conducted without an interval to induce oxidative stress. Results. Uric acid after performing pre-administration period submaximal exercise was elevated by 11.7% (p<0.05) but dropped by 10.9% in response to submaximal test after 10 days of chocolate intake. Blood lactate increased immediately following the submaximal tests up to 6.6 mmol.l-1 and 6.1 mmol.l-1 respectively. Lactate was significantly lower after the dark chocolate treatment. Following submaximal tests pre-administration period glucose was elevated to 5.65 mmol.l-1 whereas post chocolate administration glucose levels were reduced significantly. Liver enzymes changes were found within the upper reference range. Aspartate-aminotransferase levels were raised by 14.8% after both tests. No changes in γ-aminotransferase, triglycerides and cholesterol were found. Conclusion. Dark chocolate short-term administration could modulate and benefit metabolic changes in uric acid and lactate in response to submaximal exerciseinduced oxidative stress.