Resistance and Endurance Exercises Showcase Benefit for Patients With Breast Cancer

A combination of resistant exercises (such as lifting weights) and endurance exercises (such as walking or jogging) have been found to help patients with breast cancer combat depression and improve quality of life (QOL) and social functioning by improving cardiorespiratory fitness muscular endurance and muscular strength, according to a systematic review and meta‑analysis recently published in Nature Scientific Reports.¹

Furthermore, the findings demonstrated that combining resistance exercises with endurance exercises also helped patients significantly reduce fatigue. These data are important, the study authors noted, because fatigue affects between 62% and 85% of patients receiving adjuvant therapies—such as chemotherapy, radiotherapy, hormone therapy, and forms of targeted therapy—for breast cancer.²

“The findings presented show combined exercise interventions elicit significant enduring benefits to global fatigue during adjuvant therapy in breast cancer patients,” the authors said. “They also suggest a lasting clinical benefit for combined interventions to improving the remaining factors (cardiorespiratory fitness, depression, muscular endurance, muscular strength, QOL, and social functioning) thus improving physical fitness and mental wellbeing.”

Investigators canvassed PubMed, BioMed Central, Scopus, Web of Science Core collection, Cochrane Library, and Ovid for records containing the search terms “endurance” and “resistance exercise” with “breast cancer.” Initially, 9488 records were identified as evaluable. Criteria for eligibility dictated that the studies needed to be a published, randomized, controlled clinical trial with a complete database, contain assessment on endurance/aerobic impact on patients with breast cancer with at least 20 minutes of exercise per session, be written in English, and be published between 2010 and 2020.

After screening and assessing the records for eligibility and qualitative synthesis, investigators had 18 total studies evaluable for the meta-analysis.

Overall, investigators found that the 2 exercises combined elicited a positive effect on muscular strength size (standardized mean difference [SMD], 0.47; 95% CI, −0.46 to 1.40; I2 = 87%; P = .235). This analysis also achieved optimal power (91.86%) and prediction intervals anticipate this positive effect to appear again in future studies.

Similarly, the combined intervention was linked to improved QOL among the patient population (SMD, 0.18; 95% CI, −0.27 to 0.63; I2 = 31%; P = .295). Prediction models also anticipate this positive effect will appear again in upcoming analyses.In terms of social functioning, a positive effect was observed (SMD, 0.26; 95% CI, − 0.33 to 0.86; P = .39), but power analysis and prediction intervals were not able to be carried out.

For depression, the effect of the combined exercise types was inconclusive, but investigators did determine a small negative effect size for resistance exercise alone in female patients undergoing adjuvant therapy (SMD, − 0.02; 95% CI, − 0.28 to 0.24; I2 = 0%; P = .895). However, the power analysis was low (5.26%)

Finally, in terms of global fatigue, the combined exercise efforts yielded a significant negative effect size (SMD, −0.26; 95% CI, − 0.46 to − 0.07; I2 = 0%; P = .008). Prediction intervals suggested that this effect will be replicated in future studies.

In conclusion, although acknowledging that more research is needed, the authors expressed hope that these findings will “progress literature towards improving the process of adjuvant treatment for breast cancer patients to minimize its detrimental side effects. This will help those undergoing aggressive cancer treatments to return to a functional lifestyle posttreatment.”

References

1. Mok J, Brown MJ, Akram EC, Morris MA. The lasting effects of resistance and endurance exercise interventions on breast cancer patient mental wellbeing and physical fitness. Sci Rep. 2022;12:2504. doi:10.1038/s41598-022-07446-3
2. Exercise improves physical and mental side effects of breast cancer treatments, new study finds. Loughborough University. News release. March 25, 2022. Accessed March 30, 2022. https://bit.ly/3DqR8eY