Optimizing exercise prescription during breast cancer rehabilitation in women: Analysis of the load-velocity relationship in the box squat exercise.

The aims of this study were to assess (i) the load-velocity relationship during the box squat exercise in women survivors of breast cancer, (ii) which velocity variable (mean velocity [MV], mean propulsive velocity [MPV], or peak velocity [PV]) shows stronger relationship with the relative load (%1RM), and (iii) which regression model (linear [LA] or polynomic [PA]) provides a greater fit for predicting the velocities associated with each %1RM. Nineteen women survivors of breast cancer (age: 53.2 ± 6.9 years, weight: 70.9 ± 13.1 kg, and height: 163.5 ± 7.4 cm) completed an incremental load test up to one-repetition maximum in the box squat exercise. The MV, MPV, and the PV were measured during the concentric phase of each repetition with a linear velocity transducer. These measurements were analyzed by regression models using LA and PA. Strong correlations of MV with %1RM (R2 = 0.903/0.904; the standard error of the estimate (SEE) = 0.05 m.s-1 by LA/PA) and MPV (R2 = 0.900; SEE = 0.06 m.s-1 by LA and PA) were observed. In contrast, PV showed a weaker association with %1RM (R2 = 0.704; SEE = 0.15 m.s-1 by LA and PA). The MV and MPV of 1RM was 0.22 ± 0.04 m·s-1, whereas the PV at 1RM was 0.63 ± 0.18 m.s-1. These findings suggest that the use of MV to prescribe relative loads during resistance training, as well as LA and PA regression models, accurately predicted velocities for each %1RM. Assessing and prescribing resistance exercises during breast cancer rehabilitation can be facilitated through the monitoring of movement velocity.

Does a Resistance Training Program Affect Between-arms Volume Difference and Shoulder-arm Disabilities in Female Breast Cancer Survivors? The Role of Surgery Type and Treatments. Secondary Outcomes of the EFICAN Trial.

OBJECTIVE: The aims were (i) to assess the effects of a 12-week resistance training program on between-arms volume difference and shoulder-arm disabilities in breast cancer survivors and (ii) to evaluate whether the main risk factors for developing cancer-related lymphedema and shoulder-arm disabilities were associated with the effects of the training program. DESIGN: Randomized controlled trial. SETTING: University facilities. PARTICIPANTS: 60 female breast cancer survivors participated. ELIGIBILITY CRITERIA: to be a breast cancer survivor, and to have completed surgery, chemotherapy, and/or radiotherapy up to 10 years before recruitment. EXCLUSION CRITERIA: metastatic breast cancer, a breast reconstruction intervention planned within 6 months, any absolute contraindication for exercise, to perform more than 300 minutes/week of structured exercise. INTERVENTIONS: Participants were randomized to an exercise group (12-week resistance training program) or a control group. MAIN OUTCOME MEASURES: Between-arms volume difference, shoulder-arm disabilities, and upper-limb muscular strength were evaluated at baseline and at week 12. Treatment-related information was registered from medical history. RESULTS: No between-group differences were observed on between-arms volume difference (1.207; 95% CI -0.964, 3.377; P=.270) or shoulder-arm disabilities (2.070; 95% CI -4.362, 8.501; P=.521) after the training program. Likewise, there was no association of surgery type, presence of lymph node resection, chemotherapy, radiotherapy, and hormone therapy with the changes in between-arms volume and perceived shoulder-arm disabilities after the intervention. However, a higher increase in upper limb muscular strength was associated with a reduced shoulder-arm disabilities (-0.429; P=.020) in the exercise group. CONCLUSIONS: The findings suggest that resistance training does not affect between-arms volume difference and shoulder-arm disabilities in female breast cancer survivors. The main risk factors for developing lymphedema were not associated with the effects of the intervention, although a higher increase in upper-limb muscular strength was associated with reduced shoulder-arm disabilities.

Estimating the one-repetition maximum on the leg-press exercise in female breast cancer survivors.

We examined the accuracy of twelve different velocity-based methods for predicting the bilateral leg-press exercise one-repetition maximum (1RM) in breast cancer survivors. Twenty-one female breast cancer survivors (age 50.2 ± 10.8 years) performed an incremental loading test up to the 1RM. Individual load-velocity relationships were modeled by linear and quadratic polynomial regression models considering the mean velocity (MV) and peak velocity (PV) values recorded at five incremental loads (~45-55-65-75-85% of 1RM) (multiple-point methods) and by a linear regression model considering only the two distant loads (~45-85% of 1RM) (two-point method). The 1RM was always estimated through these load-velocity relationships as the load associated with a general (MV: 0.24 m/s; PV: 0.60 m/s) and an individual (MV and PV of the 1RM trial) minimal velocity threshold (MVT). Compared to the actual 1RM, the 1RMs estimated by all linear regression models showed trivial differences (Hedge's g ranged from 0.08 to 0.17), very large to nearly perfect correlations (r ranged from 0.87 to 0.95), and no heteroscedasticity of the errors (coefficient of determination (r2) < 0.10 obtained from the relationship of the raw differences between the actual and predicted 1RMs with their average value). Given the acceptable and comparable accuracy for all 1RM linear prediction methods, the two-point method and a general MVT could be recommended to simplify the testing procedure of the bilateral leg-press 1RM in breast cancer survivors.

Effects of a 12-week supervised resistance training program, combined with home-based physical activity, on physical fitness and quality of life in female breast cancer survivors: the EFICAN randomized controlled trial.

PURPOSE: This study assessed the effects of 12-week supervised resistance training combined with home-based physical activity on physical fitness, cancer-related fatigue, depressive symptoms, health-related quality of life (HRQoL), and life satisfaction in female breast cancer survivors. METHODS: A parallel-group, outcome assessor-blinded, randomized controlled trial included 60 female breast cancer survivors who had completed their core treatments within the previous 10 years. Through computer-generated simple randomization, participants were assigned to resistance training (RTG; two sessions/week for 12 weeks plus instructions to undertake ≥ 10,000 steps/d) or control (CG; ≥ 10,000 steps/d only). Outcomes were evaluated at baseline and week 12. Muscular strength was assessed with electromechanical dynamometry. A standardized full-body muscular strength score was the primary outcome. Secondary outcomes included cardiorespiratory fitness, shoulder mobility, cancer-related fatigue, depressive symptoms, HRQoL, and life satisfaction. RESULTS: Thirty-two participants were assigned to RTG (29 achieved ≥ 75% attendance) and 28 to CG (all completed the trial). Intention-to-treat analyses revealed that the standardized full-body muscular strength score increased significantly in the RTG compared to the CG (0.718; 95% CI 0.361-1.074, P < 0.001, Cohen's d = 1.04). This increase was consistent for the standardized scores of upper-body (0.727; 95% CI 0.294-1.160, P = 0.001, d = 0.87) and lower-body (0.709; 95% CI 0.324-1.094, P = 0.001, d = 0.96) strength. There was no effect on cardiorespiratory fitness, shoulder flexion, cancer-related fatigue, depressive symptoms, HRQoL, or life satisfaction. The sensitivity analyses confirmed these results. CONCLUSION: and implication for cancer survivors. In female breast cancer survivors who had completed their core treatments within the past 10 years, adding two weekly sessions of supervised resistance training to a prescription of home-based physical activity for 12 weeks produced a large increase in upper-, lower-, and full-body muscular strength, while other fitness components and patient-reported outcomes did not improve. TRIAL REGISTRATION NUMBER: ISRCTN14601208.

Absolute and Relative Handgrip Strength as Indicators of Self-Reported Physical Function and Quality of Life in Breast Cancer Survivors: The EFICAN Study.

BACKGROUND: Although breast cancer (BC) is the most prevalent type of cancer in the world, its high survival rate implies that many people live long after the treatments and face their side effects. The physical function (PF) and health-related quality of life (HRQoL) of people surviving BC decreases significantly, which makes important to identify markers that may be associated with a better health status and prognosis. Previous studies suggest that handgrip strength (HGS) and HGS relative to the body mass index (rHGS) are good indicators of PF and HRQoL in different populations. However, it is unknown whether this applies to BC survivors. This study aimed to evaluate the association of HGS and rHGS with PF and HRQoL in this population. METHODS: Sixty female BC survivors participated. Handgrip strength was assessed with a dynamometer. Arm volume was estimated and upper limb impairments, as well as cancer-related fatigue, depression, life satisfaction and HRQoL, were assessed using standardized questionnaires. RESULTS: Higher levels of HGS and rHGS were associated with higher levels of HRQoL, lower cancer-related fatigue, and fewer problems with the affected arm. CONCLUSIONS: These results suggest that HGS may be a good indicator of self-reported PF and HRQoL in female BC survivors.

¿Es la fuerza de prensión manual un buen indicador de condición física y composición corporal en pacientes con cáncer de mama que han terminado los tratamientos centrales de la enfermedad? Estudio EFICAN / A força de preensão manual é um bom indicador da condição física e da composição corporal em doentes com cancro da mama que completaram os tratamentos centrais da doença? Estudo EFICAN / Is handgrip strength a good indicator of physical fitness and body composition in breast cancer patients who have completed their core treatments? The EFICAN study

Objetivo: evaluar la asociación entre la fuerza de prensión manual (FPM) y diversos parámetros de condición física y composición corporal en mujeres supervivientes de cáncer de mama.Método: se realizó un estudio transversal con los datos basales del ensayo clínico EFICAN (Ejercicio FÍsico para supervivientes de CÁNcer de mama). Participaron 60 mujeres supervivientes de cáncer de mama que habían terminado los tratamientos centrales de la enfermedad en los 10 años previos al comienzo del estudio, que no presentaban enfermedad pulmonar o cardiovascular, cáncer de mama metastásico, ni tenían prevista una intervención para reconstrucción mamaria en un plazo de 3 meses desde el comienzo del estudio. Se evaluó la fuerza de prensión manual mediante dinamometría manual, la fuerza muscular isométrica pico mediante dinamometría electromecánica funcional, el fitness cardiorrespiratorio (VO2máx) se estimó a través del Siconolfi step test, la amplitud de movimiento (ADM) en flexión de hombro mediante goniometría digital, y la composición corporal mediante bioimpedancia.Resultados: se observó una asociación positiva de la FPM con la masa muscular (r=0.423), y con la fuerza isométrica de miembro superior (r=0.523) e inferior (r=0.335), y una asociación negativa de la FPM con el porcentaje de grasa corporal (r=-0.405). Sin embargo, no se encontró asociación entre FPM y VO2máx ni ADM del hombro (P>0.05).Conclusiones: estos resultados sugieren que la FPM puede ser un buen indicador de fuerza muscular, así como de composición corporal en mujeres supervivientes de cáncer de mama. Futuros estudios prospectivos deberán evaluar el valor predictivo de la FPM en esta población. (AU)

Objectives: this study evaluated the association between handgrip strength (HGS) and various parameters of physical fitness and body composition in female breast cancer survivors.Methods: a cross-sectional study was conducted with the baseline data from the EFICAN (Ejercicio FÍsico para supervivientes de CÁNcer de mama) clinical trial. 60 female breast cancer survivors who had completed the core treatments of the disease in the 10 years prior to the study beginning, who didn’t have any cardiovascular or pulmonary disease, metastatic breast cancer or awaited breast cancer reconstruction in the following 3 months, participated. Handgrip strength was assessed using a digital dynamometer, peak isometric strength was determined using an electromechanical dynamometer, cardiorespiratory fitness (VO2máx) was estimated through the Siconolfi step test, shoulder flexion mobility was assessed through digital goniometry and body composition was determined using a bioelectrical impedance device.Results: positive associations between HGS and muscle mass (r=0.423), isometric upper-limb (r=0.523) and lower-limb (r=0.335) strength were found, and a negative association between HGS and fat mass percentage (r=-0.405) was also found. However, no associations between HGS and VO2máx or shoulder flexion mobility were found (P>0.05).Conclusions: these results suggest that HGS may be a good indicator of muscular strength and body composition in female breast cancer survivors. Future prospective studies are needed to assess the predictive value of HGS in this population. (AU)

Objetivo: avaliar a associação entre a força de preensão manual (FPM) e vários parâmetros de condição física e composição corporal em mulheres sobreviventes de cancro da mama.Método: foi realizado um estudo transversal utilizando dados de base do ensaio clínico EFICAN (Physical Exercise for Breast Cancer Survivors). Participaram sessenta mulheres sobreviventes de cancro da mama que tinham concluído os tratamentos centrais da doença nos 10 anos anteriores ao início do estudo, que não tinham doenças pulmonares ou cardiovasculares, cancro da mama metastásico, ou que não estavam programadas para se submeterem à reconstrução da mama nos 3 meses seguintes ao início do estudo. A força de preensão manual foi avaliada por dinamometria manual, o pico de força muscular isométrica por meio de dinamometria electromecânica funcional, a capacidade cardiorrespiratória (VO2máx) foi estimada pelo Siconolfi step test, a amplitude de movimento (ADM) em flexão do ombro por meio de goniometria digital, e a composição corporal por bioimpedância.Resultados: observámos uma associação positiva de FPM com massa muscular (r=0,423), e com força isométrica de membro superior (r=0,523) e membro inferior (r=0,335), e uma associação negativa de FPM com percentagem de gordura corporal (r=-0,405). Contudo, não foi encontrada qualquer associação entre FPM e VO2max ou ADM de ombro (P>0.05).Conclusões: estes resultados sugerem que a FPM pode ser um bom indicador da força muscular, bem como da composição corporal das mulheres sobreviventes de cancro da mama. Os futuros estudos prospectivos devem avaliar o valor preditivo do FPM nesta população. (AU)

Supervised Exercise Immediately After Bariatric Surgery: the Study Protocol of the EFIBAR Randomized Controlled Trial.

BACKGROUND: Previous studies have investigated weight loss caused by exercise following bariatric surgery. However, in most cases, the training program is poorly reported; the exercise type, volume, and intensity are briefly mentioned; and the sample size, selection criteria, and follow-up time vary greatly across studies. PURPOSE: The EFIBAR study aims to investigate over 1 year the effects of a 16-week supervised exercise program, initiated immediately after bariatric surgery, on weight loss (primary outcome), body composition, cardiometabolic risk, physical fitness, and quality of life in patients with severe/extreme obesity. MATERIAL AND METHODS: The EFIBAR study is a parallel-group, superiority, randomized controlled trial (RCT), comprising 80 surgery patients. Half of the participants, randomly selected, perform a 16-week supervised exercise program, including both strength and aerobic training, starting immediately after the surgery (7-14 days). For each participant, all primary and secondary outcomes are measured at three different time points: (i) before the surgery, (ii) after the intervention (≈4 months), and (iii) 1 year after the surgery. CONCLUSION: The EFIBAR study will provide new insights into the multidimensional benefits of exercise in adults with severe/extreme obesity following bariatric surgery. TRIAL REGISTRATION: EFIBAR randomized controlled trial was prospectively registered at Clinicaltrials.gov (NCT03497546) on April 13, 2018.

Effects of a 12-week resistance and aerobic exercise program on muscular strength and quality of life in breast cancer survivors: Study protocol for the EFICAN randomized controlled trial.

BACKGROUND: The number of people living with the side effects of breast cancer treatment (eg, loss of muscular mass and muscular strength, upper-limb mobility and disability, lymphedema, cardiac toxicity, and reduced quality of life) is increasing yearly. These consequences can be improved through exercise, specially combining resistance and aerobic training. Previous exercise trials have not been consistent in applying training principles and standardized reporting, and this partly explains the variability in obtained results. The aim of this study is to assess the effect of a 12-week supervised resistance exercise program combined with home-based aerobic exercise, compared with home-based aerobic exercise only, on muscular strength and several aspects of health-related quality of life in breast cancer survivors. To maximize transparency, replicability, and clinical applicability, the intervention is described following the consensus on exercise reporting template. METHODS: This study is a parallel-group randomized controlled trial in which 60 female breast cancer survivors, who have completed central treatments of the disease in the last 5 years, will be randomly assigned to either an experimental group that will perform a total of 24 progressive resistance training sessions for 12 weeks (ie, 2 weeks of individual training and 10 weeks of micro-group training) and will be requested to undertake 10,000 steps/d, or a control group that will be requested to undertake 10,000 steps/d, only. Outcomes will be evaluated at baseline and at week 12. Primary outcome measure is peak isometric muscular strength of the lower- and upper-body, assessed with several exercises through an electromechanical dynamometer. Secondary outcomes include cardiorespiratory fitness, upper-joint mobility and disability, health-related quality of life, cancer-related fatigue, depression, life satisfaction, and presence of lymphedema. DISCUSSION: This study aims to investigate the extent to which a 12-week supervised and progressive resistance exercise program, in addition to home-based aerobic physical activity, might improve muscular strength and health-related quality of life in breast cancer survivors. The comprehensive description of the intervention will likely contribute to enhancing exercise prescription in this population. TRIAL REGISTRATION NUMBER: ISRCTN14601208.