Medicine & Science in Sports & Exercise:
F-22D Free Communication/Slide Cardiac Rehabilitation
1Institute of Sports and Preventive Medicine and Department of Cardiology, University of Saarland, Saarbruecken, Germany
(Sponsor: John A. Smith, FACSM)
Several studies show that patients suffering from chronic heart failure (CHF) caused by ischemic cardiomyopathy can profit clinically from endurance training. Our aim was to investigate the effect of 3 months low-intensity training in patients with idiopathic dilated cardiomyopathy. Submaximal parameters for training prescription and ergometric evaluation of success were utilized.
24 CHF patients with idiopathic dilated cardiomyopathy (angiographically proven) were randomly assigned to either a training group (T: age 54± 10, n=7 NYHA II, n=3 NYHA III) or a sedentary control group (CO: age 49± 7, n=9 NYHA II, n=5 NYHA III). T underwent 12 weeks of supervised training on a cycle ergometer (4–5 d/wk, 45 min/d) at an intensity corresponding to the measured ventilatory threshold (VT). Ramp protocols that included simultaneous determination of gas exchange parameters, heart rate, and blood lactate concentration were carried out in both groups before and after completion of the program.
VT increased significantly by 0.08 1/min in T (p < 0.01 versus CO: −0.03 1/min). During incremental exercise average HR decreases of 8–11 bpm were detected in T as compared to 1–3 bpm in CO (p = 0.09). Significant decreases in blood lactate concentration could only be found at higher exercise intensities (9th min of ramp protocol). VO2 increased for given workloads by an average of 0.06 1/min in T during incremental exercise, whereas an average decrease of 0.04 1/min could be detected in CO (p < 0.05). VE decreased by an average of 0.1 1/min in T and 2.5 1/min in CO (p < 0.05), respectively.
Low intensity endurance training is effective in patients with idiopathic dilated cardiomyopathy. Submaximal parameters can simultaneously be used as indicators of improvement and prescriptors of training. Neither improved cycling economy nor changes in breathing patterns are responsible for the observed endurance gains.