Positive and Negative Expectations Associated with Coffee andEnergy Drinks: Implications for Placebo–Nocebo Researchin Sports

Background: Nutritional expectations have been shown to influence exercise performance via placebo and nocebo effects. The present study aimed to evaluate performance-enhancement expectations for coffee and energy drinks using the Stanford Expectations of Treatment Scale. Methods: A total of 402 participants (48.5% male) with an average exercise history of 4.53 years, engaging in average physical activity 3.91 times per week,were included in the study. Data collection was conducted through the Qualtrics platform.Results: Participants exhibited significantly higher positive expectations for coffee com-pared to energy drinks (p = 0.002), whereas negative expectations were more pronounced for energy drinks than for coffee (p < 0.001). Males and individuals engaging in anaerobic exercise expressed more positive expectations for energy drinks than females and those participating in aerobic or mixed exercise regimens. Additionally, high-frequency exercisers(≥4 sessions per week) reported greater positive expectations for both beverages and fewer negative expectations for coffee than low-frequency exercisers (≤3 sessions per week).Correlational analyses revealed weak but significant associations between expectations and variables such as exercise history, frequency, intensity, and age. Conclusions: The findings suggest that coffee is perceived as a more effective performance enhancer and exhibits greater placebo-inducing potential than energy drinks, which may elicit stronger nocebo effects. These group-specific perceptions should be considered by trainers, coaches,and researchers when addressing placebo–nocebo mechanisms in the context of sports and exercise.