"I've got plenty of energy when I'm doing something I want to do": applying self-determination theory to exercise motivation in people with prostate cancer.

PURPOSE: Androgen deprivation therapy (ADT) for prostate cancer adversely affects quality of life. Whilst exercise is effective for ameliorating many side effects, most people are inactive, with lack of motivation a key barrier. Self-determination theory (SDT) specifies the quality, rather than quantity, of motivation as essential for optimal engagement. We aimed to explore exercise motivation in men on ADT through the theoretical lens of SDT.

METHODS

As part of a mixed-method longitudinal study, semi-structured interviews exploring exercise behaviour and perceptions, were conducted with people receiving ADT for prostate cancer. Thematic analysis identified motivation themes aligned with SDT concepts.

RESULTS

Twenty-four men participated (median age 74 years; ECOG 0: 92%, metastatic: 29%). We identified two key themes: (1) type of exercise motivation and (2) use of need-supportive techniques in exercise environments. Motivations ranged from intrinsic (for enjoyment) to external (compliance with other's expectations). Key strategies to support psychological needs included offering choice in exercise programming, providing meaningful rationales for exercise, tailored guidance from exercise professionals, and social support.

CONCLUSIONS

This SDT-grounded study provides insights into motivations driving exercise in people receiving ADT and how social and healthcare contexts influence these motivations. The study underscores the importance of considering exercise motivation when discussing, referring, and designing tailored exercise interventions to ensure they are need-supportive to optimise engagement.

IMPLICATIONS FOR CANCER SURVIVORS: This study highlights the importance of exercise interventions that are supportive of psychological needs. Incorporating need-supportive strategies may enhance exercise participation and improve physical and psychosocial outcomes for men receiving ADT.