Perioperative chemotherapy with fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT4) is the standard perioperative treatment for resectable and advanced gastric adenocarcinoma. Although the FLOT4 regimen have shown increases in the overall survival, response rate, and progression-free survival, it is also associated with substantial toxicities. Prehabilitation is an effective strategy to improve physical fitness in cancer patients and reverse functional limitations and inadequate levels of physical activity that are associated with worse postoperative outcomes and treatment response. Therefore, the main objective of this study is to evaluate the effects of an online, supervised exercise-based prehabilitation program on the cardiorespiratory fitness level, functional fitness and quality of life among adults with gastric cancer undergoing neoadjuvant chemotherapy.