Yoga therapy to reduce fatigue in cancer: effects of reminder e-mails and long-term efficacy

OBJECTIVE: To examine the efficacy of reminder e-mails to continue yoga therapy on practice frequency and fatigue in cancer patients and long-term effects of yoga on fatigue, depression, and quality of life. METHODOLOGY: One hundred two cancer patients who completed an 8-week yoga therapy were randomly allocated to two groups: reminder (N = 51) vs. no-reminder group (N = 51). After completing yoga therapy, the reminder group received weekly e-mails for 24 weeks, which reminded them of practicing yoga, whereas the no-reminder group did not. Primary outcomes were fatigue and practice frequency, and long-term outcomes were fatigue, depression, and quality of life. Data were assessed using questionnaires after yoga therapy (T1) and 6 months after completing yoga therapy (T2). RESULT: A significantly stronger reduction of general (p = 0.038, d = 0.42) and emotional fatigue (p = 0.004, d = 0.59) and a higher increase of practice frequency (p = 0.015, d = 0.52) between T1 and T2 were found for the reminder group compared to the no-reminder group. In the mediation model, practice frequency as a mediator partially explained the changes in emotional fatigue (indirect effect B = − 0.10). Long-term effects of yoga therapy regarding fatigue, depression, and quality of life were found (F > 7.46, p < 0.001, d > 0.54). CONCLUSION: Weekly reminder e-mails after yoga therapy can positively affect general and emotional fatigue and help cancer patients with fatigue establish a regular yoga practice at home. However, higher practice frequency did not lead to higher physical or cognitive fatigue improvement, suggesting other factors that mediate efficacy on physical or cognitive fatigue, such as mindfulness or side effects of therapy.