Motivational, Affective and Performance Effects of Caffeine Supplementation

The main objective of the study is to evaluate the influence of caffeine intake on participants' energetic arousal, affect, motivation to achieve a training goal, satisfaction with training, and the sense of agency during training. Consequently, participants will engage in three sessions: caffeine, placebo, and no substance (in counterbalanced order). During each session, their affective and motivational states will be assessed, along with the performance of a standardized physical exercise test. The investigators hypothesize that participants who consume caffeine (caffeine condition) will exhibit higher levels of energy and motivation compared to the other two groups. Additionally, they are expected to experience greater optimism and expectancy regarding their training goals and achieve better results in the physical exercise test. A secondary aim of the study is to examine the impact of genetic variability on motivational and affective states of participants, as well as their performance in the physical exercise test after caffeine. The investigators will assess the CYP1A2 (-163C \> A, rs762551; characterized such as "fast" (AA genotype) and "slow" caffeine metabolizers (C-carriers)) and ADORA2A (1976T \> C; rs5751876; characterized by "high" (TT genotype) or "low" sensitivity to caffeine (C-carriers)).