This study investigates the supplementation practices among fitness trainers in Istanbul, focusing on their experiences with supplements aimed at enhancing recovery and endurance. Utilizing a mixed-methods approach, the research involved a structured survey of 20 fitness trainers, gathering quantitative data on supplementation habits and qualitative feedback on their effectiveness. The results highlight trainers' widespread use of Branched-Chain Amino Acids (BCAAs), whey protein, creatine, pre-workout supplements, and L-carnitine to support muscle recovery and endurance during intense training sessions. The findings underscore the importance of these supplements in fitness trainers' routines, enabling them to sustain high training volumes and avoid overtraining. Additionally, the study reveals the role of ZMA in improving sleep quality, thereby enhancing recovery and overall performance. This research provides valuable insights into how these supplements contribute to trainers' overall fitness and performance, offering practical recommendations for optimizing physical capabilities.