Performance under pressure is one of the primary features of competitive sports. Considering that increased competition levels are typically accompanied by elevated stress and anxiety, athletes' ability to cope with stress has gained even more importance in recent years. Accordingly, the current trial, entitled Mindfulness-based Peak Performance (MBPP), will take an interdisciplinary approach (e.g., sport psychology, sports training, and cognitive neuroscience), to more definitively examine whether a MBPP affects athletic performance under pressure and relevant mental attributes. This study is an 8-week, three-arm, randomized controlled trial (RCT). A total of 90 athletes, aged between 18 and 30 years will be recruited. Eligible participants will be randomly assigned into (1) an MBPP group, (2) a self-talk (ST) group, and (3) a wait-list control (WC) group. The MBPP and ST interventions consist of a 60-min session weekly for 8 weeks. Primary outcomes are endurance performance and performance-relevant mental attributes including behavior (i.e., stress response, emotion regulation, and engagement) and neurocognitive processes (e.g., attention, executive function, brain resting state), which will be assessed at baseline and post-intervention. Dispositional mindfulness and athletic psychological skills will be secondary outcomes, also assessed at baseline and post-intervention. The MBPP and ST are expected to improve performance under pressure, but MBPP is expected to show greater improvement than ST. Additionally, we expect the MBPP will improve the relevant mental attributes. The results from this trial might provide rigorous evidence and insight into MBI application in the sports context. ClinicalTrials.govregistration:NCT05612295.