Background —Dyspnea and fatigue are the main causes of exercise limitation in chronic heart failure (CHF) patients, whose peak inspiratory (Pi _max ) and expiratory pressures (Pe _max ) are often reduced. The aim of this study was to examine the relationship between respiratory muscle performance and oxygen kinetics. Methods and Results —A total of 55 patients (NYHA class I to III) and 11 healthy subjects underwent cardiopulmonary exercise tests (CPET) on a treadmill. In 45 of the 55 patients (group I) and in healthy subjects (group II), pulmonary function tests, Pi _max , and Pe _max were measured before and 10 minutes after exercise, and oxygen kinetics were monitored throughout and during early recovery from CPET. The first degree slope of oxygen consumption (V̇ o ₂ ) decline during early recovery (V̇ o ₂ /t-slope) and V̇ o ₂ half-time (T _1/2 ) were calculated. In 10 of the 55 CHF patients (group III), the measurements of Pi _max were repeated 2, 5, and 10 minutes after CPET. A >10% reduction in Pi _max after CPET (subgroup IA) was measured in 11 of 45 patients. In contrast, 34 of 45 CHF patients (subgroup IB) and all control subjects (group II) had Pi _max >90% of baseline value after CPET. Subgroup IA patients had significantly lower peak V̇ o ₂ (13.5±2.1 versus 17.8±5.6 mL · kg ⁻¹ · min ⁻¹ ; P <0.001), lower anaerobic thresholds (10.1±2.4 versus 13.6±4.6 mL · kg ⁻¹ · min ⁻¹ ; P =0.003) and lower V̇ o ₂ /t-slopes (0.365±0.126 versus 0.519±0.227 L · min ⁻¹ · min ⁻¹ ; P =0.008) than subgroup IB patients. Conclusions —The reduction of Pi _max after exercise is associated with prolonged early recovery of oxygen kinetics, which may explain, in part, the role played by respiratory muscles in exercise intolerance in CHF patients.