Introduction: Physical activity (PA) is considered an important factor to enhance the survival rate and overall quality of life in colorectal cancer (CRC) patients. However, a small percentage of patients comply with PA recommendations and most of them decrease their PA levels during chemotherapy. Theoretical frameworks could be useful for guiding exercise programs focused on the promotion of patients’ adherence to PA. Nevertheless, few studies have applied self-determination theory (SDT), one of the most prominent motivational theories, to understand exercise motivation in interventions with CRC patients. The aim of this study was to explore the benefits of a SDT-based 6-month exercise program (FIT-CANCER) regarding satisfaction of basic psychological needs and different psychological and behavioural consequences in CRC patients (stage II-III) during adjuvant chemotherapy. Methods: Qualitative data from 16 patients (nine men and seven women; M_age = 64.00, SD = 11.58), six relatives (M_age = 55.00, SD = 15.09) and five healthcare professionals (M_age = 40.40, SD = 9.66) were obtained through semi-structured interviews and field notes (N = 27). Results: Participants perceived that the motivational exercise program satisfied CRC patients’ needs for autonomy, competence, relatedness and novelty, giving rise to positive psychological consequences during chemotherapy treatment, such as enjoyment of exercise, optimism, vitality, sociability and keeping some good memories. The program allowed patients to feel that they were actively doing something important to overcome their cancer, an aspect that could foster their psychological well-being. Participants perceived that patients increased their exercise participation during chemotherapy treatment, even during the COVID-19 pandemic, with an online adaptation of the exercise program, and integrated exercise into their lifestyle. Participants also highlighted the importance of patients’ belonging to a group undergoing a similar situation and the instructor's knowledge, specialization and empathy. Conclusion: Motivational exercise programs could help improve CRC patients’ psychosocial and behavioural outcomes during chemotherapy treatment.

简介：体力活动（PA）被认为是提高结直肠癌（CRC）患者生存率和整体生活质量的重要因素。然而，一小部分患者遵守 PA 建议，并且大多数患者在化疗期间降低了 PA 水平。理论框架可用于指导旨在促进患者坚持 PA 的锻炼计划。然而，很少有研究应用最著名的动机理论之一的自我决定理论（SDT）来理解CRC患者干预中的运动动机。本研究的目的是探讨基于 SDT 的 6 个月锻炼计划 (FIT-CANCER) 对于满足 CRC 患者（II-III 期）辅助化疗期间的基本心理需求以及不同心理和行为后果的益处。方法：来自 16 名患者（9 名男性和 7 名女性；M_年龄 = 64.00，SD  = 11.58）、6 名亲属（M_年龄 = 55.00，SD  = 15.09）和 5 名医疗保健专业人员（M_年龄 = 40.40，SD  = 9.66）的定性数据通过半结构化访谈和现场笔记获得（N  = 27）。结果：参与者认为，激励性运动计划满足了结直肠癌患者的自主性、能力、关联性和新颖性的需求，在化疗期间产生了积极的心理后果，例如享受运动、乐观、活力、社交和保留一些美好的记忆。该计划让患者感觉到他们正在积极做一些重要的事情来克服癌症，这可以促进他们的心理健康。参与者认为，通过在线调整锻炼计划，并将锻炼融入他们的生活方式，患者在化疗期间增加了锻炼参与度，甚至在 COVID-19 大流行期间也是如此。参与者还强调了患者属于经历类似情况的群体以及导师的知识、专业和同理心的重要性。结论：激励性运动计划有助于改善 CRC 患者化疗期间的社会心理和行为结果。