Effect of a 3-month Exercise Intervention on Physical Performance, Body Composition, Depression and Autonomic Nervous System in Breast Cancer Survivors: A Pilot Study

Abstract

Purpose: Breast cancer patients are at increased risk of developing comorbidities such as lymphedema, sarcopenia, osteoporosis and cardiovascular disease after breast cancer treatment. These complications contribute to a decrease in quality of life, cardiorespiratory fitness and muscle strength. Regular and long-term physical activity is an effective non-pharmacological strategy that can improve physical, psychological and social outcomes. The aim of our research was to evaluate the effect of various modes of an exercise intervention on physical performance, body composition, depression and autonomic nervous system in breast cancer survivors. Methods: 16 women after surgery with hormonal treatment enter the research. Thirteen of them completed the controlled, quasi-experimental study (54 ± 9 yrs, 164cm ± 6cm, 72 ± 12kg) and were divided into 3 groups according to their place of living: trained under supervision (n=5) (SUPERV), trained at home without supervision by videos (n=7) (HOME) and with no prescribed physical activity (n=4) (CON). Exercise intervention lasted 3 months and comprised of 60 min training units 3 × week (aerobic with resistant exercise in a 2 : 1 mode combined with regular weekly yoga and breathing exercises). The exercise intensity was set individually at 65–75% of HRR based on spiroergometry and was continuously controlled by heart rate monitors. The same principles applied to the HOME group, which, in addition to heart rate monitors, recorded frequency, length, HRmax, HRavg, and Borg scale of intensity perception. VO2max, BMI, fat mass, depression level (Beck’s depression inventory) and the power of the autonomic nervous system (total power and sympatho-vagal balance) were analyzed. For data evaluation we used descriptive statistics and Cohens d effect size. Results: 3 women dropped out of research because of medical reason. In all groups VO2max values increased. The largest increase in VO2max values was in SUPERV group by 36%, in HOME group by 20% and in CON group by 2%. Body weight decreased for groups SUPERV (˗1.2 kg) and CON (-0.1kg), for HOME group there was an increase (+0.2 kg). Body mass index decreased for SUPERV group (-0.4), for HOME and CON it increased (both +0.1). Total power decreased in SUPERV (-0.6) and HOME group (-0.2), in CON has not changed. The same results were achieved by the sympatho-vagal balance, only the CON group increased. Values from Beck’s depression inventory decreased for all groups, most for CON group. Conclusion: A 3-months of supervised and controlled exercise had a significant effect on physical fitness and body composition in comparison with non-supervised home-based physical intervention. Our results indicate that it is strongly advisable to apply a supervised exercise program to induce positive physiological changes in breast cancer survivors as part of aftercare.