Can the Six-Minute Walk Test Be Used to Individualize Physical Activity Intensity in Patients with Breast Cancer?

BACKGROUND: Adapted physical activity (APA) aids breast cancer patients. It is necessary to use an adapted target heart rate (HR) when prescribing exercise intensity. METHODS: In total, 138 patients previously included in two published randomized clinical trials underwent the CPET and 6MWT before and after adjuvant therapy. Of these patients, 85 had performed APA, and 53 had received only the usual therapy. HRs were recorded during the two tests. RESULTS: Before starting chemotherapy, good agreement (intraclass correlation (ICC) 0.69; confidence interval at 95% IC0.95 (0.591-0.769); p < 0.001) and a moderate correlation were evident between the 6MWT-HR and ventilatory threshold HR of the CPET (r = 0.70; p < 0.001). Good agreement and a high positive correlation were noted only in the group who engaged in APA (ICC 0.77; IC0.95 (0.659-0.848); p < 0.001; r = 0.8; p < 0.01); moderate agreement and a moderate positive correlation were apparent in the control group (ICC 0.57; IC0.95 (0.329-0.74); p < 0.001; r = 0.6; p < 0.01). The correlations were independent of age and body mass index. CONCLUSIONS: The 6MWT-HR can be used to prescribe exercise intensity for breast cancer patients both before and after specific treatment with concomitant APA.

Speckle tracking echocardiographic analysis of left ventricular systolic and diastolic function in young elite rugby players.

BACKGROUND: Little evidence exists in the literature on the effects of mixed-type training on the left ventricle (LV). This study focused on the effects of training on the morphological and functional characteristics of the left ventricle. This study investigated the effects of training on LV function using Speckle Tracking Imaging (STI) in high-level, young rugby players. METHODS: This prospective and longitudinal cohort study enrolled ten young controls and 24 young rugby players (13 high-level rugby players; 11 amateur rugby players) were included in the study. Standard Tissue Doppler Imaging Echocardiography and STI were performed in this study before and after the season. LV mass and pulsed wave Doppler inflow recording of the LV, including early and atrial waves, were carried out in 2-3-4 chamber views. We assessed three normal strains, rotation, and torsion in the LV. RESULTS: The main results of this study demonstrated that no differences existed between the three groups in LV functional parameters, the longitudinal circumferential and radial strain indices, and rotation and torsion indices. In the professional group, a significantly higher end-diastolic diameter (P<0.001), septal (P<0.05) and posterior (P<0.01) wall thickness, and LV mass (P<0.01) was observed. There were no differences in diastolic function. CONCLUSIONS: This study confirmed that young, elite rugby players have normal LV remodeling and normal LV function under resting conditions.

Effects of home-based exercise training on VO2 in breast cancer patients under adjuvant or neoadjuvant chemotherapy (SAPA): a randomized controlled trial.

BACKGROUND: Breast cancer chemotherapy is associated with a decline in measured cardiorespiratory fitness and increased fatigue. Physical activity has emerged as a feasible intervention to limit these side effects. Quantitative evaluation is necessary to propose a better-adapted physical activity and to evaluate efficacy. AIM: We undertook a prospective study to assess the effects of a home-based adapted physical activity (APA) program on aerobic capacity, strength, and fatigue in women treated with adjuvant or neoadjuvant chemotherapy for breast cancer versus usual care. DESIGN: This was an open two-arm, randomized controlled trial. SETTING: Study included outpatient groups in the Department of Physiology and Medical Oncology of a hospital in France. POPULATION: Forty-four patients treated with adjuvant or neoadjuvant chemotherapy for breast cancer. METHODS: Patients were randomly assigned to a control group or an APA group. Intervention consisted of a 3-week, home-based, supervised, combined APA program (endurance and resistance training) during 27 weeks. The primary endpoint was cardiopulmonary function assessed by maximal peak oxygen consumption (VO2peak). Secondary endpoints included a 6-minute Walking Test (6MWT), and assessment of muscular strength, fatigue, quality of life, physical activity level, and anxiety/depression. RESULTS: At 27 weeks, VO2peak increased by 1.83±0.68 ml.min-1.kg-1 in the APA group (P=0.009) and decreased by 1.31±0.65 mL.min-1.kg-1 in the control group (P=0.046). The difference between the two groups was not significant (2.26±1.53 mL.min-1.kg-1, P=0.140) in intention-to-treat analysis, but it was significant in per protocol analysis (3.49±1.64 mL.min-1.kg-1, P=0.049). At 27 and 54 weeks, no significant differences were observed between the two groups for the cardiopulmonary exercise test, 6MWT, quadriceps strength, or quality of life. CONCLUSIONS: In breast cancer patients, a home-based supervised program during chemotherapy and radiotherapy treatment may be safe, feasible and increase VO2peak. In this study, heavy evaluation tests explain patient's non-adherence and do not permit to obtain statistically significant results between APA and control groups. CLINICAL REHABILITATION IMPACT: Aerobic home-based adapted physical activity is beneficial on aerobic capacity.