Abstract
PURPOSE: Exercise training induces several beneficial effects in patients with chronic heart failure (CHF). This study investigated the effects of high-intensity aerobic interval training (AIT) compared with combined AIT and strength training (COM) on early ventilatory and metabolic recovery pattern after symptom-limited cardiopulmonary exercise testing (CPET) in CHF patients.
METHODS: Stable CHF patients (N = 42; 54 +/- 10 years [mean +/- SD], 35 males) participated in an exercise training program for 12 weeks, 3 times per week. Participants were randomly assigned to either AIT (n = 20) or COM group (n = 22). Cardiopulmonary exercise testing was performed before and after completion of the program. Primary measurements included absolute and percentage difference of oxygen uptake, carbon dioxide output, minute ventilation (
E), tidal volume (VT), respiratory rate, and the first-degree slope of oxygen uptake (
O2/t slope) and carbon dioxide output (
CO2/t slope) during the first minute of recovery after maximal exercise.
RESULTS: The COM group had a greater improvement in the absolute and the percentage difference of
E (P = .03 and P = .04, respectively) and respiratory rate (P = .02 and P = .01, respectively) during the first minute of recovery period after exercise compared with the AIT group alone. No significant changes were noted for VT measurements. A significant increase in
CO2/t slope was observed in COM compared with the AIT group (P = .01). There was a trend for a greater increase in
O2/t slope in the COM group (P = .07).
CONCLUSIONS: The addition of strength training to AIT induces significant beneficial effects in terms of ventilatory and metabolic recovery kinetics than AIT alone in CHF patients, possibly indicating greater ventilatory efficiency and metabolic improvement.