Athletes use a variety of common strategies to stimulate arousal, cognition, and performance before morning training, such as a coffee, energy drinks, or fruit. Each method contains stimulant compounds shown to antagonize central adenosine receptors, such as caffeine or quercetin, a phenolic flavonoid.
PURPOSE: The objective of this pilot study was to explore the performance outcomes of consuming a whole food containing quercetin versus caffeinated beverages before exercise and cognitive tasks.
METHODS: Six volunteers (n=6, age= 22 ± 3) were tested in a single-blind crossover study on 5 different days, separated by at least 48 hours. On their first visit, subjects performed a treadmill graded exercise test to exhaustion and a familiarization trial on a computerized Flanker Cognitive Test, which evaluated % accuracy and reaction time. Gas exchange values were recorded and the exercise levels were determined using the respiratory compensation point in which there was an a-linear increase in VEO2, and decrease in PetCO2. On the following 4 visits, subjects were randomly assigned to fasted (CON), a 12 oz caffeinated energy drink (CED), 0.114 oz/kg bw black coffee (COF) or an apple (APP). Thirty minutes after consumption, subjects performed a Flanker test, followed by a time to exhaustion test (TET) performed at the respiratory compensation point. Data were analyzed using a repeated measures ANOVA.
RESULTS: No significant differences existed between the two cognitive components of the Flanker test (Accuracy: p=.08, Reaction Time: p=.83). The mean (SD) times to exhaustion were 317.2 (59.4) (CON), 372.5 (112.3) (APP), 408.2 (98.2) (CED), and 364.0 (95.3) (COF) min. No significant differences were found in TET (p=.09, η2=.34).
CONCLUSIONS: There were no differences among the common morning strategies to increase accuracy and reaction time, markers of cognition. Since no significant differences were found between the apple and caffeinated beverages, an apple may be just as beneficial as specifically formulated energy drinks. Future research should control for relative amounts of adenosine blockade, carbohydrate intake, and calories to determine whether foods containing quercetin, work as well as caffeinated beverages for cognition and exercise performance.