Chronic Effects of Resistance Training in Breast Cancer Survivors

Abstract

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.

Figure 1

Flow diagram of selection process using PRISMA.

Figure 2

Forest plot on upper body strength (bench press: 1 RM, lb).

Figure 3

Forest plot on lower body strength (leg press: 1 RM, lb).

Figure 4

Forest plot on body composition: body fat (%).

Figure 5

Forest plot on body composition: fat mass (kg).

Figure 6

Forest plot on body composition: lean body mass (kg).