The main findings of this research can be summarized as follows: 1) CT promoted improvements in functional capacity, but not in body composition in TG women; 2) CT favored positive changes in body image; 3) Variables related to appearance were correlated with the vulnerability dimension in TG; 4) Variables related to body appearance and function were directly related to body image in the CG. The latter was our most surprising finding, particularly the waist circumference, which appears to be an important marker in the body image of women with breast cancer not submitted to physical activity.
The effect of CT was confirmed by increased arm muscle strength and improvements in VO2max. These results corroborate studies in the literature which submitted women with breast cancer to protocols composed of aerobic and strength exercises and found similar results [20–22]. CT prevents the physical deconditioning inherent in cancer treatment . These variables enhance the perception of this population of improvements in their quality of life . De Luca et al. further point out that CT promotes greater adherence to physical activity, due to the diversification of exercises.
However, in the current study, there were no positive changes in body mass, percentage of fat, BMI, or other anthropometric indices in either group. It is worth noting that, despite this, the maintenance of these variables already indicates a good follow-up, since the disease and its treatment promote negative changes in body composition. Similar results were found in women with breast cancer submitted to strength training , aerobic and combined (strength and aerobic) protocols . On the other hand, De Luca et al.  observed a reduction in fat percentage after intervention with CT in the same population. This difference may be attributed to the superiority in the intervention time (24 weeks) and method of analysis (bioimpedance), performed by the researchers. However, the multi-frequency electrical bioimpedance analysis method indicates greater precision when performed in a segmental way, due to the morphological variation in the tissues.
On the other hand, there was an interaction between time and group for the right thigh and changes in fat-free mass and waist circumference after 12 weeks. Despite the maintenance of these variables, promoting health through physical training, there was an increase in the waist circumference (WC) of both groups, which shows a negative trend and can be attributed to the cancer treatment. According to Oliveira et al.  and Figueiredo et al.  there is a large incidence of high WC in patients with breast cancer, which is linked to cardiovascular risk; these authors suggest that this population requires adherence to a nutritional program. However, the study by Kim et al.  demonstrated a reduction in WC after a 12-week CT intervention, this difference may be due to the stage of the treatment, since all the patients were survivors of breast cancer. Further studies are needed to define the type of intervention effective in the reduction of visceral fat in patients in the treatment of breast cancer.
Another central axis of this research is the investigation of body image changes. This was analyzed from the theoretical model with six dimensions and validated for Brazilian women with breast cancer. Three dimensions demonstrated sensitivity to CT: limitation, concern for the body, and transparency. After the intervention, the TG demonstrated a significant reduction in the perception of functional limitations of the body, such as movement restrictions and oncologic fatigue. Arab et al.  in one of the few studies in this scope performed in Brazil, presented similar results, although the protocol applied by them was different, with only resistance training over 12 weeks. The authors attribute the improvement to the higher physical competence acquired for the performance of motor tasks. Unlike our data, Arab et al.  did not find training effects in the other dimensions . It is possible that this difference is associated with the specificity of the intervention given.
Concern with the body is a striking feature in women with breast cancer, which in Brazilian women (who culturally already have this concern), is accentuated either through the chemotherapy or mastectomy process . As we hypothesized, the TG showed a tendency to reduce concerns with the body, that is, with their general appearance, including concern about the gain or loss of weight. Previous studies have demonstrated similar results after both strength training and aerobic training, in which improvements in the perception of body appearance and lower concern with weight were detected, respectively.
Concern with appearance is related to the alterations promoted by the disease and treatment, which may be less or more visible. Issues relating to concern with how obvious the disease is (expressed by changes in appearance) were denominated transparency by the authors. This variable was significantly different between the groups, so that women who did not receive the intervention with the CT presented higher scores in this dimension. We did not find similar studies that addressed this point, which limits our discussion. However, a qualitative research with Latina women with breast cancer, identified that the acceptance of changes in appearance is considered a central axis in body image . The authors encourage the development of intervention strategies that favor the acceptance of appearance during and after treatment. Our results suggest that CT may be of potential assistance. This becomes more consistent when we observe the gross scores of all analyzed dimensions, and find that, although there is no statistical significance, there is an increase in the CG and reduction in the TG, indicating a tendency to reduce body image impairment with the practice of CT.
In the same direction, the next question was to identify whether improvements in body image could be attributed to changes in appearance and/or functionality as a result of CT. This hypothesis was partially rejected because the TG did not present a significant correlation between body image and functional capacity. On the other hand, the body composition, BMI, weight, WHR, WC, and fat-free mass variables, although not presenting significant changes in our sample, were negatively correlated with body image, specifically with the vulnerability dimension, in the basal period, assuming statistical significance after the intervention. This fact leads us to reflect that the body experience with the CT may have directed the attention of these women to their body measurements, however, differently to women without breast cancer, since the literature indicates that BMI, WHR, WC, and fat-free mass are predictors of negative changes in body image, such as body dissatisfaction[42, 40]. In our study, the opposite occurred, the higher these scores, the lower the feeling of invasion of the body by the disease, which may have consequently caused a lower sensation of vulnerability.
Unlike our results, Speck et al.and Pinto et al., after interventions with strength and aerobic training, respectively, in women with breast cancer, did not identify any variable of body composition and/or function capable of mediating the effect of training on the improvements found in body image. On the other hand, the positive effect on functional capacity, identified here and in the studies above, is pointed out by the authors as a factors that influences body image, although indirectly. Speck et al.  explain that muscular strength provides benefits to the general quality of life and this, in turn, mediates the intervention in the perception of the body. Pinto et al.  concluded that the improvement found in patients' self-assessment of their physical condition (energy, strength, and agility) is consistent with the increase in VO2max, thus indicating a refinement of the patient about her physical condition.
In contrast to the TG, the body image of the women who were not submitted to the intervention was influenced, over time, as much by the variables related to appearance as by body functionality. Waist circumference, a variable commonly associated positively with female body dissatisfaction, precisely because it delineates female body forms, manifested itself in an opposite way for all dimensions of body image. Thus, the smaller this variable, the greater the perception of functional limitations, the concern with the arm and with the body, accentuating the feelings of vulnerability, visibility of the disease (transparency), and body stigma.
The percentage of fat, also considered a predictor of body dissatisfaction in women, especially for the lean body ideal, maintained this characteristic for the CG, in proportion to the Body Stigma, body concerns, transparency, and vulnerability. It is possible that this is due to the gradual and complex process of acceptance of changes in appearance from disease and treatment, requiring women to learn and deal with these changes.
Functional ability also presented an influence on CG body image. The CG showed a negative correlation between arm muscle strength and the limitations and transparency dimensions (despite the absence of significance in the basal period) in all phases. Concerns with the arm were positively related (although not significant at baseline) to muscle strength, assuming statistical significance, but negative, after 12 weeks. The opposite occurred between concerns about the arm and VO2max. Ohira et al., when developing research similar to ours, hypothesized that women with breast cancer feel empowered psychologically as they become more physically effective. Although we cannot state that the benefits of CT positively and directly impacted body image in the TG, the authors' idea applies in our results, since we observed that impairments in functional capacity were negatively associated with CG body image.
However, we believe that, unlike the CG, the TG may have benefited from body experiences in the intervention, thus impacting dimensions which, although not evaluated herein, are indicated in the specific literature as linked to this process: cognitive, affective, and behavioral. Interventions with physical exercise can provide the sensation of regaining control of the body itself, which may translate into a greater sense of self-efficacy in other areas of life . Thus, it is possible to infer that CT promotes subjective experiences that go beyond body appearance and function, although indirectly influencing it.
Finally, we agree with the point of view of Speck et al., in which the authors point out that the mechanism of impact of training on the concern with the body of women with breast cancer remains unclear. Thus, we encourage researchers to engage in research of this scope that seeks to identify whether CT can be considered a protective element for negative changes in body image in this population. In addition to this gap, we also recognize some methodological limitations of this research. Initially, the sample size is restricted, which hampers generalizations of the results. The high exclusion of participants may negatively impact the results of randomized clinical trials, biasing the research. In addition, the history of physical exercise of non-eligible patients was not investigated, information that may be useful for understanding some results. Finally, the reduced number of articles with the same theme in Brazilian women affected by breast cancer made the discussion difficult, since cultural factors are extremely relevant to the body image constructs .
Although we analyzed important variables in the elaboration of the body image of this population, such as the type of surgery [13, 4, 44], a relevant point in this context is breast reconstruction, since it is known that women undergoing reconstruction are less dissatisfied with their bodies. Accordingly, we recommend new studies that compare women with and without breast reconstruction and analyze the relationship of body image with body composition and functional capacity.