Quantity of Resistance Exercise for Breast Cancer Patients: Does the Dose Match the Objective?

ABSTRACT: Rosenberg, J, Hyde, PN, Yancy, WS, Ford, KM, and Champ, CE. Quantity of resistance exercise for breast cancer patients: does the dose match the objective? J Strength Cond Res 35(5): 1467-1476, 2021-There is currently a lack of consensus as to what defines exercise and resistance training in the cancer setting and whether current studies comply with exercise guidelines. This study aimed to quantify the available research studies using resistance training exercise interventions in the breast cancer setting for future clinical trial utilization. We systemically reviewed all available resistance exercise studies during and after breast cancer treatment in an attempt to quantify to the prescribed dose and whether regimens aligned with general exercise guidelines to improve functional mobility, body composition, and metabolic function. They were then compared with recommendations set forth by the national committees that create evidence-based exercise guidelines. Fifty studies met the initial criteria, with 35 meeting analysis criteria for evaluation. Fifteen studies evaluated an exercise regimen during cancer treatment, and 20 evaluated a regimen after treatment. The average adherence rates were 84% for all studies. Only 23 studies listed specific exercises used within the protocol. Most exercise regimens relied on open chain movements and machine exercises. Around half of studies met criteria to achieve hypertrophy, and 66% met American College of Sports Medicine exercise guidelines for cancer patients. A minority of breast cancer studies implementing a resistance training exercise regimen prescribed a regimen or specific dose that follows general exercise guidelines. This study highlights a potential deficiency in exercise programs designed for patients with breast cancer, and these findings should be considered in future study design.

Neuromuscular contributions to disability in children with cerebral palsy and the impact of dynamic stretching orthoses and therapeutic exercise interventions: a narrative review.

Background and Objective: Cerebral palsy (CP) is the most common motor disability in children. The initial lesion to the developing brain may result in a myriad of neuromuscular comorbidities, including mobility deficiencies. The neuromuscular contributions to disability and rehabilitative frameworks specific to children with CP have been investigated separately. However, few reviews have examined the relationship between neuromuscular pathophysiology and rehabilitative frameworks among children with CP. Therefore, the purpose of this review was to investigate the impact of dynamic stretching orthoses and therapeutic exercise on range of motion (ROM), aerobic capacity, and mobility in relation to the neuromuscular contributions to disability in children with CP. Methods: Reviews of PubMed, Google Scholar, and Web of Science were conducted to identify literature focusing on the neuromuscular pathophysiology contributing to disability in children with CP and rehabilitative frameworks associated with this population. The search used a combination of keywords and subject headings to include 'cerebral palsy', 'musculoskeletal', 'neuromuscular', 'spasticity', 'rehabilitation', 'exercise', 'aerobic', and 'orthosis'. Selected manuscripts featured original cross-sectional and longitudinal research and meta-analyses. Key Content and Findings: A total of 303 manuscripts were initially identified through search terms, with 182 articles excluded based on title and abstract evaluation, leaving 121 manuscripts for full-text analysis. Seven studies meeting the narrative review criteria were included. Evidence supporting the efficacy of dynamic stretching orthoses for improving lower extremity ROM is inconclusive. Aerobic and progressive resistive training may be beneficial for improving aerobic capacity and muscle strength in children with CP, which may result in enhanced mobility. Conclusions: Depending on the individual's clinical presentation, ROM and therapeutic exercise may be implemented to optimize function. Incorporating progressive resistive and aerobic exercises into a rehabilitation plan may improve mobility and aerobic capacity. As such, clinicians should consider resistance and aerobic exercise prescription as part of a long-term treatment plan for children with CP.

EXERT-BC: A pilot study of an exercise regimen designed to improve functional mobility, body composition, and strength after the treatment for breast cancer.

PURPOSE: Resistance training may offer several unique advantages within breast cancer (BC) survivorship care; however, safety concerns have limited the application of high-intensity compound movements necessary to elicit optimal changes in body composition, strength, and quality of life in this population. The EXERT-BC trial assesses the safety and feasibility of an evidence-based, dose-escalated resistance training regimen among BC survivors, with the goal of improving physical and metabolic function, mobility, muscle mass, and body composition. METHODS: Participants included women with breast cancer underwent a 3-month thrice weekly exercise regimen involving dose escalation of high-intensity compound exercises. Coprimary outcomes included safety and adherence. Pre- and post-regimen assessment included body composition testing, functional mobility and balance, total load (weight × repetitions × sets) across compound exercises, and patient reported quality of life. Pairwise comparison was performed via the paired t test. RESULTS: Fourty participants completed a 3-month exercise regimen, with a median age of 57 years (range, 27-74 years) and 73% having stage 0-2 BC. BC therapies concurrent with exercise included anti-estrogen therapy (80%), radiotherapy (30%), and non-hormonal systemic therapy (15%). No adverse events were observed aside from a single case of self-limited knee pain. Session attendance exceeded a prespecified threshold of 75%, and 98% patients reported ongoing compliance to an exercise regimen following regimen completion. Significant reductions in percent body fat (p < 0.001) and increases in percent muscle mass (p = 0.011) were observed. Significant increases in resting metabolic rate (p = 0.023), bilateral grip strength (p < 0.001), functional movement screen (p < 0.001), bilateral Y-Balance testing (p < 0.001), and Godin questionnaire scores (p < 0.001) were observed. CONCLUSION: A 3-month dose-escalated resistance training regimen comprising high-intensity compound movements appears safe with a high degree of adherence among breast cancer survivors, resulting in demonstrable improvements in body composition, metabolic parameters, strength increases, and patient-reported quality of life.

EXERT-BC: Prospective Study of an Exercise Regimen After Treatment for Breast Cancer.

Purpose EXERT-BC is a dose-escalated resistance training regimen created to improve body composition, strength, and balance in women treated for breast cancer (BC). Herein, we report the interim analysis. Women treated for BC underwent this 3-month exercise regimen in an exercise oncology facility with continual monitoring of load and strength. Twenty women completed the IRB-approved protocol, with a mean age of 57 years (range 41-74). Concurrent therapies included anti-estrogen therapy (73%), chemotherapy (14%), and radiotherapy (23%). 27% of women endorsed prior exercise. Subjects missed an average of 1.75 classes (range 0-7), with all meeting adherence over 75%. No injuries or adverse events were reported aside from muscle soreness and 2 days of knee pain. Significant differences in body composition at completion included reduced body fat (38.2% vs. 36.7%, p=0.003), and increased muscle mass (33.1% vs. 37.1%, p<0.001), functional mobility screening (9.82 vs. 11.73, p=0.018), and Y-balance (left: 72.4 vs. 85.3, p=0.001; right: 70.3 vs. 85.2. p<0.001). Significant increases in load were demonstrated: split squat (p<0.001), trap bar deadlift (p=0.035), inclined dumbbell press (p<0.001), and bird dog rows (p<0.001). Dose-escalated resistance training in women with BC is safe and feasible, endorsing significant improvements across body composition, balance, and strength.

Resistance Training for Patients with Cancer: A Conceptual Framework for Maximizing Strength, Power, Functional Mobility, and Body Composition to Optimize Health and Outcomes.

There are many benefits to the addition of exercise to cancer treatment and survivorship, particularly with resistance training regimens that target hypertrophy, bone mineral density, strength, functional mobility, and body composition. These goals are best achieved through a series of individualized high-intensity compound movements that mirror functional mobility patterns and sufficiently stress the musculoskeletal system. As a result of adequate stress, the body will engage compensatory cellular mechanisms that improve the structural integrity of bones and muscles, stimulate metabolism and the immune system, optimize functional performance, and minimize mechanical injury risk. The current evidence suggests that application of the above exercise principles, practiced in a safe environment under expert observation, may offer patients with cancer an effective means of improving overall health and cancer-specific outcomes. The following article poses several important questions certified exercise specialists and physicians should consider when prescribing resistance exercise for patients with cancer.

Metabolic syndrome: Operational definitions and aerobic and resistance training benefits on physical and metabolic health in children and adolescents.

BACKGROUND: The variation in parameters for childhood metabolic syndrome (MetS) has hindered the development of a consensus for the diagnostic criteria in this group. Despite these inconsistencies, it is accepted that exercise can ameliorate the deleterious effects of MetS. However, direct comparison between aerobic versus resistance exercise on MetS symptomology in adolescents is lacking. AIM: Aim of this review was to discuss controversies associated with current MetS operation definitions in adolescents and present a review summarizing longitudinal studies relevant to the influence of aerobic and resistance training on children with MetS. METHODS: Reviews of PubMed and Web of Science were conducted to identify literature focusing on the influence of aerobic and resistance training on children with MetS. Selected manuscripts featured longitudinal research only. RESULTS: A universally accepted definition of MetS for the pediatric population has yet to be established. As such, consensus regarding diagnostic criteria for MetS among children is lacking despite the presence of various descriptions in the literature. Though studies support the importance of aerobic and resistance exercise to combat comorbidities associated with MetS, longitudinal studies investigating the benefits of each exercise type among adolescents are limited and inconsistent. CONCLUSION: An improved understanding of the impact of aerobic and resistance training on children with MetS is clinically relevant because it may facilitate more appropriate exercise recommendations for children with MetS. Additional large cohort studies are warranted to determine optimal exercise type.

Incretin Hormones: Pathophysiological Risk Factors and Potential Targets for Type 2 Diabetes.

Type 2 diabetes (T2D) is a multifaceted metabolic disorder associated with distinctive pathophysiological disturbances. One of the pathophysiological risk factors observed in T2D is dysregulation of the incretin hormones, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Both hormones stimulate insulin secretion by acting postprandially on pancreatic ß-cell receptors. Oral glucose administration stimulates increased insulin secretion in comparison with isoglycemic intravenous glucose administration, a phenomenon known as the incretin effect. While the evidence for incretin defects in individuals with T2D is growing, the etiology behind this attenuated incretin effect in T2D is not clearly understood. Given their central role in T2D pathophysiology, incretins are promising targets for T2D therapeutics. The present review synthesizes the recent attempts to explain the biological importance of incretin hormones and explore potential pharmacological approaches that target the incretins.