ABSTRACT
Introduction:
Caffeine is presently the most consumed substance in the world and, associated with physical exercise, brings important achievements in performance.
Objective:
To investigate the biochemical effects of acute caffeine supplementation after endurance exercise in Wistar rats.
Methods:
Twenty-seven male Wistar rats have been used, weighing 357 ± 73 g, randomly distributed in three groups: 1) Control (without supplementa-tion and exercise), 2) Saline (saline+ exercise), 3) Caffeine (6 mg/kg caffeine + exercise). Supplements have been administered 50 minutes before the 60-minute swimming test. Immediately after swimming, the animals have been sacrificed for blood sampling and biopsy of liver and muscle tissue. The levels of blood glucose, triglycerides, serum lactate and concentrations of glycogen in liver and muscle have been analyzed. All results were expressed as mean ± SEM. The statistical analysis used was the ANOVA one way test, being considered statistically signi-ficant only P<0.05.
Results:
Muscle glycogen and lactate did not differ between groups. Caffeine has preserved the levels of blood glucose and liver glycogen (P<0.05). Caffeine has elevated the levels of plasma glycerol in 31.2% (P<0.05), when compared to the group exercised without supplementation.
Conclusion:
The study reports that the use of pre-exercise caffeine promotes biochemical alterations that can improve metabolic efficiency during the endurance exercise.
Keywords:
caffeine; exercise; blood glucose; glycogen
