Quantifying the Lasting Effects of Resistance and Endurance Exercise Interventions on Mental Wellbeing and Physical Fitness in Women Receiving Adjuvant Treatment for Breast Cancer Compared to Adjuvant Therapy Alone: A Contemporary Systematic Review and Meta-Analysis

Introduction: Breast cancer is a persisting global burden for health services with cases and deaths projected to rise in future years. Surgery complemented by adjuvant therapy is commonly used to treat breast cancer, however comes with detrimental side effects to physical fitness and mental wellbeing. Aim: The aim of this systematic review and meta-analysis is to determine whether resistance and endurance interventions performed during adjuvant treatment can lastingly ameliorate these side effects. Methods: : A systematic literature search was performed in various electronic databases. Papers were assessed for bias and grouped based on intervention design. RStudio was used to perform the meta-analyses for each group using the ‘meta’ package. Publication bias and power analyses were also conducted. These methods conform to PRISMA guidelines. Results: : Combined resistance and endurance interventions elicited significant long-lasting improvements in global fatigue and were beneficial to the remaining side effects. Individually, resistance and endurance interventions non-significantly improved these side effects. Resistance interventions elicited higher benefits overall. Conclusion: Exercise interventions have lasting clinical benefits in ameliorating adjuvant therapy side effects, which negatively impact physical fitness and mental wellbeing. These interventions are of clinical value to enhance adherence rates and avoid comorbidities such as sarcopenia, thus improving disease prognosis.