Walking training at the heart rate of pain threshold improves cardiovascular function and autonomic regulation in intermittent claudication: A randomized controlled trial

Abstract

Objectives: This study investigated the effects of walking training (WT) on cardiovascular function and autonomic regulation in patents with intermittent claudication (IC). Design: Randomized controlled trial. Methods: Forty-two male patients with IC (>= 50 years) were randomly allocated into two groups: control (CG, n = 20, 30 min of stretching exercises) and WT (WTG, n = 22, 15 bouts of 2 min of walking interpolated by 2 min of upright rest-walking intensity was set at the heart rate of pain threshold). Both interventions were performed twice/week for 12 weeks. Walking capacity (maximal treadmill test), blood pressure (auscultatory), cardiac output (CO2 rebreathing), heart rate (ECG), stroke volume, systemic vascular resistance, forearm and calf vascular resistance (plethysmography), and low (LF) and high frequency (HF) components of heart rate variability and spontaneous baroreflex sensitivity were measured at baseline and after 12 weeks of the study. Results: WT increased total walking distance (+302 +/- 85 m, p = 0.001) and spontaneous baroreflex sensitivity (+2.13 +/- 1.07 ms/mmHg, p = 0.02). Additionally, at rest, WT decreased systolic and mean blood pressures (-10 +/- 3 and -5 +/- 2 mmHg, p = 0.001 and p = 0.01, respectively), cardiac output (-0.37 +/- 0.24 l/min, p = 0.03), heart rate (-4 +/- 2 bpm, p = 0.001), forearm vascular resistance (-8.5 +/- 2.8 U, p = 0.02) and LF/HF (-1.24 +/- 0.99, p = 0.001). No change was observed in the CG. Conclusions: In addition to increasing walking capacity, WT improved cardiovascular function and autonomic regulation in patients with IC.