Mitigating cardiovascular risk: the effect of low-intensity cycle-ergometer training on appendicular muscle mass and hypertension-related factors in breast cancer patients undergoing chemotherapy

Breast cancer survivors face a dual burden: chemotherapy-induced muscle wasting (sarcopenia) and increased long-term cardiovascular risk, including hypertension. This study evaluated whether a low-intensity aerobic exercise intervention could mitigate muscle loss and potentially influence hypertension-related physiological factors. In a randomized controlled trial, 22 breast cancer patients undergoing chemotherapy were allocated to an intervention group (n=11) or a control group (n=11). The intervention group completed an 8-week, twice-weekly program of supervised cycle-ergometer training at low intensity (30% heart rate reserve), while the control group performed breathing exercises. Appendicular Skeletal Muscle Mass Index (ASMI) was measured via Bioelectrical Impedance Analysis; blood pressure and heart rate were monitored as secondary safety and exploratory measures. Twenty participants completed the study. The exercise group showed a significant increase in ASMI (from 15.62 ± 1.50 kg/m² to 17.15 ± 2.26 kg/m², p=0.004), while the control group experienced a significant decrease (from 15.14 ± 1.69 kg/m² to 14.34 ± 1.49 kg/m², p=0.001). The between-group difference post-intervention was highly significant (p=0.004) with a large effect size (Cohen's d=1.47). Minor, non-clinical increases in blood pressure were observed in both groups, remaining within safe limits. The intervention was safe, with a 1.25% adverse event rate. Conclusion: Supervised, low-intensity cycle training effectively counteracts chemotherapy-induced muscle loss. By preserving metabolically active muscle mass, this practical intervention may serve as a foundational strategy in a holistic care model aimed at concurrently addressing sarcopenia and modifiable cardiovascular risk factors, such as hypertension, in breast cancer patients.