Interval exercise training improves tissue oxygenation in patients with chronic heart failure

Aim: Aim of our study was to evaluate the effects of interval exercise training (IT) programs, regarding whole body oxygen uptake and peripheral tissue oxygenation, in Chronic Heart Failure (CHF) patients during recovery. Methods: Twenty-six CHF patients (21 males/5 females), mean age of 49 ± 12 years, participated in the study. Fifteen patients were assigned to IT and 11 patients were assigned to IT followed by strength training. All patients were trained for 40 minutes per session, 3 times per week, for 12 weeks. They performed a symptom-limited cardiopulmonary exercise testing (CPET), before and after the completion of the program. Muscle tissue oxygen saturation (StO2) of quadriceps femoris was continuously measured by Near Infrared Spectroscopy (NIRS) during CPET and during the recovery period after the end of exercise. Results: No differences were noted between the two patient groups regarding whole body and peripheral tissue oxygenation indices and, therefore, data from all patients were pooled. After training, an increase in peak oxygen uptake (17 ± 4.5 to 19 ± 5.5 ml/kg/min, p 2 at the first minute of recovery (0.45 ± 0.2 to 0.61 ±0.3 L/min2, p ), was noted. In addition, tissue re-oxygenation time constant was decreased (65 ± 25 to 52 ± 28 sec, p