Search

Exercise is effective for improving the physical and psychological health of breast cancer patients. However, there is still controversy around its role on the immune system. Therefore, this systematic review and meta-analysis is aimed to evaluate the effect of chronic exercise on the number and activity of the immune cells that can contribute to anti-tumor immune responses, such as natural killers (NK) cells, CD + 4, or CD + 8. The main hypothesis of this study was that exercise could improve the immune system or, at least, there will not be a reduction in the number or activity of immune cells because of exercise. The search was conducted in the PubMed and Web of Science databases. Out of 244 studies reviewed, 10 studies met the inclusion criteria. The studies included in the meta-analyses showed mixed results and no significant (p > 0.05) positive or negative effects of exercise interventions in women with breast cancer. Therefore, the current evidence indicates that exercise does not significantly improve or reduce the immune system; thus, the prescription of exercise must not be discouraged due to the effects on the number and activity of immune system cells, but should be recommended due to the well-known benefits in quality of life, physical function or fatigue, and the absence of negative effects on the immune system. Further studies are needed to evaluate the effects according to the type of exercise, the type of cancer, or the timing of the intervention., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Abstract: Moraes, RF, Ferreira-Júnior, JB, Marques, VA, Vieira, A, Lira, CAB, Campos, MH, Freitas-Junior, R, Rahal, RMS, Gentil, P, and Vieira, CA. Resistance training, fatigue, quality of life, anxiety in breast cancer survivors. J Strength Cond Res 35(5): 1350-1356, 2021-Resistance training (RT) has shown to be effective in improving fatigue, quality of life (QOL), and anxiety levels among breast cancer survivors (BCS), but there is no consensus as to how this practice should be prescribed for optimal performance. This study analyses the effects of once weekly RT on fatigue, QOL, and anxiety levels among BCS. Randomized controlled trial. Twenty-five BCS (aged 54.6 ± 5.5 years) were randomized into RT or control groups. The RT group performed 8 weeks of RT (once per week). Fatigue was assessed using the Piper Fatigue scale, QOL was assessed using the SF-36, and anxiety was assessed using the STAI State-Trait Anxiety Inventory. Resistance training significantly improved the following subscales of SF-36: aspects of physical functioning (+27%, p = 0.027); physical role functioning (+54%, p = 0.008); emotional role functioning (+42%, p = 0.027); and mental health (+16%, p = 0.032). Furthermore, RT improved fatigue levels (-55%, p = 0.001 for general fatigue) and anxiety (anxiety state, -19%, p = 0.012; anxiety trait, -23%, p = 0.001). Resistance training seemed to be a positive nonpharmacological tool for the reduction of fatigue, anxiety, and for improvement of several aspects of QOL in BCS., (Copyright © 2021 National Strength and Conditioning Association.)

Objective. To analyse effects of resistance training (RT) in breast cancer survivors (BCS) and how protocols and acute variables were manipulated. Methods. Search was made at PubMed, Science Direct, and LILACS. All articles published between 2000 and 2016 were considered. Studies that met the following criteria were included: written in English, Spanish, or Portuguese; BCS who have undergone surgery, chemotherapy, and/or radiotherapy; additional RT only; analysis of muscle performance, body mass composition (BMC), psychosocial parameters, or blood biomarkers. Results. Ten studies were included. PEDro score ranged from 5 to 9. Rest interval and cadence were not reported. Two studies reported continuous training supervision. All reported improvements in muscle strength, most with low or moderate effect size (ES), but studies performed with high loads presented large ES. Five described no increased risk or exacerbation of lymphedema. Most studies that analysed BMC showed no relevant changes. Conclusions. RT has been shown to be safe for BCS, with no increased risk of lymphedema. The findings indicated that RT is efficient in increasing muscle strength; however, only one study observed significant changes in BMC. An exercise program should therefore consider the manipulation of acute and chronic variables of RT to obtain optimal results.