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    BDNF coexpresses with MTOR and is associated with muscle fiber size, lean mass and power-related traits
    (SPRINGER, 2025) Bulgay, Celal; Zorba, Erdal; Kazan, Hasan H.; Bayraktar, Isik; Uca, Merve; Ergun, Mehmet A.; John, George
    PurposeRecent research suggests a link between brain-derived neurotrophic factor (BDNF) and the mTOR signaling pathway, a key regulator of protein synthesis and muscle growth. However, it remains unclear whether BDNF influences muscle growth and power performance. Our study aimed to investigate the relationship between the expression of BDNF and MTOR genes in human skeletal muscle and examine the association between genetically predicted higher expression of the BDNF gene and muscle fiber size, lean mass, power performance, and power athlete status. MethodsThe study involved 456,382 subjects, including 285 athletes, 112 physically active individuals with muscle fiber composition data, 291 sedentary individuals with gene expression data, 5451 controls, and 450,243 UK Biobank participants. The muscle fiber composition was evaluated using immunohistochemistry, while gene expression analysis was performed using RNA sequencing. BDNF genotyping was carried out using real-time PCR or microarrays. ResultsWe found that BDNF gene expression was positively associated with MTOR gene expression in the vastus lateralis (p < 0.0001). Furthermore, genetically predicted higher BDNF expression (i.e., carriage of the C allele of the rs6265 (Val66Met) BDNF polymorphism) was positively associated with the cross-sectional area of fast-twitch muscle fibers in athletes (p = 0.0069), appendicular lean mass (p = 2.6 x 10(-)(7)), personal best scores of power athletes (p = 0.029), and power athlete status (p = 0.0056). ConclusionOur study demonstrates a positive correlation between BDNF and MTOR gene expression in human skeletal muscle, with genetically predicted higher BDNF expression associated with greater muscle fiber size, lean mass, enhanced power performance, and power athlete status.
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    Positive and Negative Expectations Associated with Coffee and Energy Drinks: Implications for Placebo-Nocebo Research in Sports
    (MDPI, 2025) Somogyi, Angela; Uca, Merve; Bulgay, Celal; Acheampong, Ernest Yeboah; de la Vega, Ricardo; Ruiz-Barquin, Roberto; Szabo, Attila
    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 compared 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.