TOPLINE: 

Exercise interventions — including aerobic exercise, combined aerobic-strength training, and strength training — were associated with improved quality of life (QoL) in women with breast cancer undergoing chemotherapy. The meta-analysis found an approximately 66% likelihood that women in exercise groups report better outcomes than those receiving standard care alone.

METHODOLOGY: 

• The meta-analysis addresses a gap in the literature by focusing specifically on women undergoing chemotherapy for breast cancer rather than on those who have survived cancer after active treatment, examining how exercise modality and dose could affect QoL outcomes.
• Researchers conducted a systematic review and meta-analysis of 21 randomized controlled trials involving 3024 women with breast cancer undergoing chemotherapy, searching five electronic databases (PubMed, Embase, Web of Science, Cochrane Library, and MEDLINE) from January 1, 2005, to May 24, 2025.
• Participants were assigned to exercise interventions including aerobic exercise, strength or resistance training, or combined aerobic-strength programs, compared with standard care or no exercise control groups.
• Primary outcome measures included validated QoL questionnaires assessed at or closest to chemotherapy completion, with QoL domains categorized into global QoL, psychosocial, and physical functioning.
• Analysis utilized standardized mean differences (Hedges g) calculated and pooled using three-level random-effects models accounting for dependent effect sizes, with moderator analyses examining exercise modality, QoL domain, and geographical region.
• Studies were included from multiple countries, with data sources primarily from North America, Europe, and Asia, and all trials were published in English between 2007 and 2025. 

TAKEAWAY: 

• Exercise interventions showed a statistically significant positive effect on QoL constructs (g, 0.434; 95% CI, 0.272-0.595; P < .0001), with substantial heterogeneity observed across studies. QoL domain categories of mental health, physical health, and global QoL each showed significant positive effects differences, the authors wrote.
• Aerobic exercise combined aerobic-strength training, and strength training alone showed significant benefits, as well.
• Significant regional variations were identified (test statistic for moderator differences, 29.05; P < .0001), with Asian studies showing the largest effect sizes (g, 0.656; 95% CI, 0.335-0.977; P < .0001), followed by North American studies (g, 0.395; 95% CI, 0.070-0.721; P = .017) and European studies (g, 0.321; 95% CI, 0.062-0.581; P = .015), according to the investigators.

IN PRACTICE:

“These findings are consistent with American Society of Clinical Oncology recommendations. Clinicians should consider recommending both aerobic exercise and combined aerobic-strength exercise,”wrote the authors of the study.

“Future studies should investigate biological and psychological mechanisms underlying modality-specific effects and examine optimal delivery models, adherence strategies, and pathways for integrating exercise into oncology care. Exercise goals in oncology are multifactorial and might require different prescriptions with varying intensity demand,” they said.

SOURCE:

The study was led by LaShae D Rolle, MPH, and Tracy E Crane, PhD, both from University of Miami Miller School of Medicine in Miami. It was published online in Lancet Healthy Longevity.

LIMITATIONS: 

The substantial heterogeneity seen in the findings of this study indicates that unmeasured factors continue to shape exercise effects on QoL. Clinical moderators such as age, tumor stage, and subtype could not be examined, because these characteristics were reported inconsistently across trials. Adherence was documented in approximately half of the studies and captured with heterogeneous methods, limiting its value as a potential moderator. Variation in QoL instruments across studies might introduce measurement bias, although the use of standardized effect sizes helps to mitigate this concern. The small number of strength-based trials restricts the generalizability of those findings, and the geographical clustering of studies in high-income countries could constrain broader applicability. The restriction to English-language publications might have excluded studies from European and Asian contexts, potentially influencing the observed regional differences.

DISCLOSURES:

No funding source was provided for this study. Another author, Kathryn H. Schmitz, PhD, disclosed receiving fees from Klose Training and Consulting. All other authors reported no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.