Correlates of resistance training in post-treatment breast cancer survivors

Psychosocial correlates of physical activity in cancer survivors: a systematic review and meta-analysis

BACKGROUND

Physical activity (PA) is a non-pharmacological approach to optimize health benefits in cancer survivors and is recommended as part of care. However, most cancer survivors fail to meet PA recommendations. The current systematic review and meta-analysis aimed to identify psychosocial correlates of free-living PA in cancer survivors.

METHODS

Three electronic databases were searched (PubMed, PsycINFO, and SportDiscus). Meta-analyses were conducted for psychosocial correlates tested ≥ 3 times.

RESULTS

Sixty-four articles were included. Eighty-eight different free-living PA correlates were identified. Meta-analyses (n = 32 studies) tested 23 PA correlates, of which 16 were significant (p < 0.05). Larger effect sizes (0.30 < ES > 0.45) were found for exercise self-efficacy, perceived behavioral control, intention, lower perceived barriers for exercise, enjoyment, perceived PA benefits, and attitudes. Small-to-moderate effects (0.18 < ES < 0.22) were found for subjective norms, physical functioning, quality of life, depression, and mental health. These findings were generally in line with narrative results.

CONCLUSIONS

This systematic review highlights important psychosocial correlates of free-living PA that can be targeted in future PA promotion interventions for cancer survivors. Constructs mainly from SCT and TPB were the most studied and appear to be associated with free-living PA in this population. However, we cannot currently assert which frameworks might be more effective. Further studies of better methodological quality, per correlate and theory, exploring longer-term associations and across different types of cancer, are needed.

IMPLICATIONS FOR CANCER SURVIVORS

Having higher exercise self-efficacy, perceived behavioral control, intention, enjoyment and perceived PA benefits, more positive attitudes towards PA, and lower perceived barriers for exercise, can help increase PA in cancer survivors.

A Systematic Review of the Mediators of Resistance Training Behavior

BACKGROUND

Resistance training (RT) has been identified as an important lifestyle activity for health. While systematic reviews have examined behavior change techniques (BCTs) used in interventions and potential correlates of RT behavior, the connection between BCTs and changes in putative mediators and RT participation have yet to be linked. The purpose of this review was to examine RT intervention effects, as coded by BCT clusters, on behavior change via capability, opportunity, and motivation as putative mediators of that change.

METHOD

Literature searches were concluded in January of 2023, using three databases. Eligible studies included a comparison group, assessed RT as an outcome, included BCTs, assessed potential mediators, and were in English. The initial search yielded 1050 hits, which was reduced to 5 to independent RT interventions. Screening of previous reviews yielded three additional papers for a total of 8 papers. Each paper was assessed for the associations between intervention effects (as BCT clusters) on mechanisms of action (a path), effects of mechanisms of action on behavior (b path), and indirect (ab path) and direct (c path) effects of BCT clusters.

RESULTS

There was support that interventions had significant effects on capability and opportunity with inconclusive effects on motivation (a path). Both capabilities and motivation had associations with RT behavior (b path). The examined studies showed that changes in capabilities have the strongest support as a mediator with some support for motivation as a mediator (ab path). Studies that used more BCT clusters seemed to have a more positive effect on behavior, yet there were no trends to suggest any one crucial BCT cluster (c path).

CONCLUSION

Current evidence suggests that capabilities and motivation are important to target in RT interventions. Future interventions would be well suited to utilize behavior change techniques that address these mediators.

Self-efficacy, motivation, and habits: psychological correlates of exercise among women with breast cancer

PURPOSE

The purpose of this analysis was to explore associations between exercise behaviour among breast cancer survivors and three behavioural constructs from distinct theories: self-efficacy from social cognitive theory, motivation from self-determination theory, and habits from habit theory.

METHODS

Breast cancer survivors (n = 204) completed a cross-sectional survey that collected demographic and disease characteristics, exercise levels, and self-efficacy, motivation, and habits. Multivariable linear regression models were used to identify constructs associated with total activity and resistance training.

RESULTS

Participants were a mean (SD) age of 57.3 (10.8) years and most were diagnosed with early-stage disease (72%) and engaged in sufficient levels of total activity (94%), though only 45% completed ≥ 2 resistance training sessions/week. Identified motivation (ꞵ[95% CI] = 7.6 [3.9-11.3]) and habits (ꞵ[95% CI] = 4.4 [1.4-7.4]) were significantly associated with total activity (as were body mass index and disease stage), whilst identified motivation (ꞵ[95% CI] = 0.6 [0.3-0.9]) and coping self-efficacy (ꞵ[95% CI] = 0.02 [< 0.01-0.03]) were significantly associated with resistance training. The models explained 27% and 16% of variance in total activity and resistance training behaviour, respectively.

CONCLUSION

Results suggest that incorporating strategies that support identified motivation, habits, and coping self-efficacy in future interventions could promote increased exercise behaviour among breast cancer populations. Future longitudinal research should examine associations with exercise in a more representative, population-based sample.

Impact of High-Intensity Circuit Resistance Exercise on Physical Fitness, Inflammation, and Immune Cells in Female Breast Cancer Survivors: A Randomized Control Trial

Questions remain about whether resistance exercise has a positive effect on immune and inflammatory cells. The purpose of this study was to evaluate the effect of 12 weeks of high-intensity circuit resistance exercise (HCRE) on inflammation and immune cells, and physical fitness, of female breast cancer survivors (FBCSs). Thirty FBCSs were randomly assigned to the HCRE (n = 15) and control (n = 15) groups. HRCE was administered for 50 min a day, 2–3 times a week, for 12 weeks. The control group only performed activities of daily living during the study period. Baseline and post-intervention measures included body composition, muscular strength, muscular endurance, flexibility, reaction time, balance, inflammation, and immune cell measurements. The results showed that HCRE improved body mass index, body fat, muscle mass, grip strength, back muscle strength, sit-up, whole-body reaction, standing on one leg with eyes closed, Y-balance test, and NKCA in FBCSs. The improvement of physical strength and immune cells of FBCSs was achieved using the 12-week HRCE program. Future studies must analyze various exercise intensities and types, and should be conducted on other cancer survivors. In addition, strategies should be developed to allow FBCSs to participate in resistance training.

The Development of the MedEx IMPACT Intervention: A Patient-Centered, Evidenced-Based and Theoretically-Informed Physical Activity Behavior Change Intervention for Individuals Living With and Beyond Cancer

Regular physical activity (PA) can address many of the negative side effects experienced by individuals following cancer treatment and support the optimization of physical and psychosocial well-being. However, many survivors of cancer are not sufficiently active to achieve these health benefits. The purpose of this study was to describe the development of a physical activity behavior change (PABC) intervention, MedEx IMPACT (IMprove Physical Activity after Cancer Treatment), which aims to increase cancer survivors’ PA levels. A review of the literature and focus groups with survivors of cancer were conducted in order to generate recommendations to inform the intervention development process. This process was guided and informed by: (1) the Medical Research Council’s (MRC) framework for the development, evaluation, and implementation of complex interventions, (2) the Behaviour Change Wheel (BCW), and (3) the Theoretical Domains Framework (TDF). Recommendations for strategies to support habitual PA and adherence to community-based exercise programs, generated by survivors of cancer who participated in 7 focus groups (n = 41), were synthesized with 13 statements of findings that were generated from 10 studies included within the review of the literature. Detailed mapping exercises are presented which outline the link between these sources, the MRC framework, the BCW and TDF, and the intervention content. MedEx IMPACT is the first PABC intervention for survivors of cancer to be developed through the application of the MRC framework, BCW, and TDF. The next phase in this research is to test the acceptability and effectiveness of MedEx IMPACT.

Clinical factors associated with adherence to aerobic and resistance physical activity guidelines among cancer prevention patients and survivors

Physical activity (PA) is a known behavior to reduce cancer risk and improve cancer survivorship, yet adherence to PA guidelines is poor among the general population and cancer survivors. The purpose of this study was to determine the extent to which patients referred for exercise consultation within a clinical cancer prevention setting were meeting aerobic and resistance physical activity (PA) guidelines and to identify factors associated with guideline adherence. Between 2013 and 2015, cancer prevention patients and cancer survivors were interviewed by an exercise physiologist within an Integrative Health Program at The University of Texas MD Anderson Cancer Prevention Center. PA adherence was defined as at least 150-minutes of moderate-intensity or 75-minutes of vigorous-intensity PA per week, along with resistance training at least 2 days per week. Logistic regression was used to determine factors associated with meeting or not meeting PA guidelines for aerobic exercise, resistance exercise, and aerobic and resistance exercise combined. Among 1,024 cancer prevention patients and survivors, 9% of patients adhered to guideline-based PA. Adherence to aerobic and resistance guidelines were 20% and 12%, respectively. Overweight or obesity was associated with not meeting guideline-based PA in both cancer prevention patients and cancer survivors. Among breast cancer survivors, combination treatment with surgery, radiation, and chemotherapy ('multimodal therapy') was robustly associated with not meeting aerobic guidelines (OR 2.20, 95% CI: 1.17 to 4.16). BMI and breast cancer treatment history are key determinants of PA behavior among cancer prevention patients and survivors. Poor adherence to PA guidelines is a key issue for cancer prevention patients and survivors, particularly obese patients and women who receive multimodal therapy for breast cancer. Identifying and connecting patients at highest risk of poor PA adherence with exercise programs is needed to improve PA, a key modifiable cancer risk factor.

Demographic, medical, social-cognitive, and environmental correlates of meeting independent and combined physical activity guidelines in kidney cancer survivors

PURPOSE

Guidelines for cancer survivors recommend both aerobic physical activity (PA) and strength training (ST). Few kidney cancer survivors (KCS) are meeting single-activity or combined guidelines; therefore, examining factors influencing PA participation is warranted. The purpose of this study is to examine demographic, medical, social-cognitive, and environmental correlates of meeting independent (i.e., aerobic-only, strength training (ST)-only) and combined guidelines (i.e., aerobic and ST) in KCS.

METHODS

KCS (N = 651) completed self-reported measures of PA and demographic, medical, social-cognitive, and perceived environmental factors. Built environment was assessed using the geographic information systems (GIS). Multinomial logistic regressions were conducted to determine the correlates of meeting the combined versus independent guidelines.

RESULTS

Compared with meeting neither guideline, meeting aerobic-only guidelines was associated with higher intentions (p < .01) and planning (p < .01); meeting ST-only guidelines was associated with higher intentions (p = .02) and planning (p < .01), lower perceived behavioral control (PBC) (p = .03), healthy weight (p = .01), and older age (p < .01); and meeting the combined guidelines were associated with higher intentions (p < .01), planning (p = .02), higher instrumental attitudes (p < .01), higher education (p = .04), better health (p < .01), and localized cancer (p = .05). Additionally, compared with neither guideline, meeting aerobic-only (p < .01) and combined (p < .01) guidelines was significantly associated with access to workout attire. Compared with neither guideline, meeting aerobic-only guidelines was associated with proximity to retail (p = .02).

CONCLUSION

PA participation correlates may vary based on the modality of interest. Interventions may differ depending on the modality promoted and whether KCS are already meeting single-modality guidelines.

Association Between Maximal Bench Press Strength and Isometric Handgrip Strength Among Breast Cancer Survivors

OBJECTIVE

To characterize the relationship between 1-repetition maximum (1-RM) bench press strength and isometric handgrip strength among breast cancer survivors.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PARTICIPANTS

Community-dwelling breast cancer survivors (N=295).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

1-RM bench press strength was measured with a barbell and exercise bench. Isometric handgrip strength was measured using an isometric dynamometer, with 3 maximal contractions of the left and right hands. All measures were conducted by staff with training in clinical exercise testing.

RESULTS

Among 295 breast cancer survivors, 1-RM bench press strength was 18.2±6.1kg (range, 2.2-43.0kg), and isometric handgrip strength was 23.5±5.8kg (range, 9.0-43.0kg). The strongest correlate of 1-RM bench press strength was the average isometric handgrip strength of both hands (r=.399; P<.0001). Mean difference analysis suggested that the average isometric handgrip strength of both hands overestimated 1-RM bench press strength by 4.7kg (95% limits of agreement, -8.2 to 17.6kg). In a multivariable linear regression model, the average isometric handgrip strength of both hands (β=.31; P<.0001) and age (β=-.20; P<.0001) were positively correlated with 1-RM bench press strength (R²=.23).

CONCLUSIONS

Isometric handgrip strength is a poor surrogate for 1-RM bench press strength among breast cancer survivors. 1-RM bench press strength and isometric handgrip strength quantify distinct components of muscular strength.

Fostering positive experiences of group-based exercise classes after breast cancer: what do women have to say?

PURPOSE

The adverse side effects of current treatments for breast cancer highlight the need for rehabilitative programmes. Group-based exercise programmes have been found to be effective in reducing symptoms and treatment side effects and improving physical and psychological health in cancer survivors. To assist programme administrators and instructors in the ongoing design and delivery of optimal group-based exercise programmes, we conducted a longitudinal qualitative study to explore breast cancer survivors' perceptions of the instructor and the climate the instructor created within the context of a group-based exercise programme, and how this contributes to women's motivational experiences.

METHOD

Seven women participating in an eight-week group-based exercise programme were interviewed at the start and end of the programme. Data were analysed using thematic analysis.

RESULTS

The instructor's attributes (energy, enthusiasm, approachability, knowledge, experience) and her focus on promoting self-improvement, personal progress, skill development and task mastery contributed to participants' positive experiences, which served to enhance their motivation to remain involved in the programme.

CONCLUSIONS

Instructors play an essential role in creating a supportive climate and fostering positive experiences in group-based exercise programmes for breast cancer survivors. Hiring caring and knowledgeable instructors who are able to create a supportive climate may enhance breast cancer survivors' experiences in group-based exercise programmes and promote sustained participation. Implications for Rehabilitation Promoting self-improvement, personal progress, skill development and task mastery can enhance breast cancer survivors' adherence to group-based exercise programmes, which can help mitigate the effects of cancer and its treatment. In addition to training leaders to run safe and effective programmes, hiring instructors who have high energy, and who are enthusiastic, approachable, knowledgeable and experienced can promote breast cancer survivors' adherence to group-based exercise programmes. Training in breast cancer management is required to allow instructors to understand the complexities of this disease and develop tailored exercise programmes. Future research needs to identify training techniques that can effectively promote exercise instructors' competence in working with breast cancer survivors.