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

Abstract

genation, in Chronic Heart Failure (CHF) patients during recovery. Methods: Twenty-six CHF patients (21 males/5 females), mean age of 49 ± 12 years, par- ticipated 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 comple- tion of the program. Muscle tissue oxygen saturation (StO2) of quadriceps femoris was continuously meas- ured 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 < 0.05), gas exchange threshold (11 ± 3.5 to 12.5 ± 3.5 ml/kg/min, p < 0.05), peak work rate achieved (105 ± 29 to 124 ± 37 Watt, p < 0.05) and the first degree slope of VO2 at the first minute of recov- ery (0.45 ± 0.2 to 0.61 ± 0.3 L/min2, p < 0.05) was noted. In addition, tissue re-oxygenation time con- stant was decreased (65 ± 25 to 52 ± 28 sec, p < 0.001). Conclusion: In conclusion, interval exercise training accelerates oxygen uptake and peripheral tissue oxy- genation during recovery from exercise in CHF patients.