High intensity one‐legged cycling improves functional sympatholysis and aerobic fitness in chronic heart failure

Abstract

Exercise intolerance and fatigue during daily activities are primary symptoms in patients with chronic heart failure (CHF). The poor correlation between the hemodynamic parameters of left ventricular performance and perceived symptoms suggests that other factors such as muscle mal perfusion plays a role in determining exercise capacity. The purpose of this study was to investigate the peripheral hemodynamic response to high intense one‐legged cycling. Leg hemodynamics were measured before and after 6 weeks of high intensity interval one‐legged cycling (90% one‐legged cycling max 4×4 min intervals with each leg, 3 times per week) in seven heart failure patients (age: 58±4 years; LVEF 34±5%; BMI 25.8±1.8 kg/m2; VO2 peak: 2.1±0.2 l/min) at rest and during one‐legged knee extensions with without arterial tyramine infusion. Data were analyzed by repeated measures two‐way ANOVA and Tuckey's honestly significant difference (HSD) post hoc procedure. Exercise training increased VO2 peak (2.2±0.2 vs. 2.5±0.3 l/min: P<0.05), Wattmax during two‐legged cycling (153±14 vs. 163±24 Watt; P<0.05), Wattmax during one‐legged knee extensor exercise (36±10 vs. 52±9 Watt; P<0.05) and 6 min walking distance (553±48 vs. 595±59 m; P<0.05). Arterial tyramine infusion lowered leg blood flow and leg vascular conduction at rest (P<0.05) with no difference before and after the training intervention. Arterial tyramine infusion during one‐legged knee extensions, lowered leg blood flow before the training intervention (P<0.05), whereas tyramine did not lower leg blood flow after the training intervention. These results suggest that high intensity one‐legged cycling improves functional sympatholysis during exercise and is beneficial for patients with chronic heart failure in regards to exercise capacity and functionality.