OBJECTIVE:
The purpose of this study was to evaluate the following 1) the effects of continuous
exercise training and interval
exercise training on the end-tidal
carbon dioxide pressure (PETCO2) response during a graded
exercise test in
patients with
coronary artery disease; and 2) the effects of
exercise training modalities on the
association between PETCO2 at the ventilatory
anaerobic threshold (VAT) and
indicators of ventilatory
efficiency and
cardiorespiratory fitness in
patients with
coronary artery disease.
METHODS:
Thirty-seven
patients (59.7 + 1.7 years) with
coronary artery disease were randomly divided into two groups continuous
exercise training (n = 20) and interval
exercise training (n = 17). All
patients performed a graded
exercise test with respiratory gas
analysis before and after three months of the
exercise training program to determine the VAT, respiratory
compensation point (RCP) and peak
oxygen consumption.
RESULTS:
After the interventions, both groups exhibited increased
cardiorespiratory fitness. Indeed, the continuous
exercise and interval
exercise training groups demonstrated increases in both ventilatory
efficiency and PETCO2 values at VAT, RCP, and peak of
exercise. Significant
associations were observed in both groups 1) continuous
exercise training (PETCO2VAT and
cardiorespiratory fitness r = 0.49; PETCO2VAT and ventilatory
efficiency r = -0.80) and 2) interval
exercise training (PETCO2VAT and
cardiorespiratory fitness r = 0.39; PETCO2VAT and ventilatory
efficiency r = -0.45).
CONCLUSIONS:
Both
exercise training modalities showed
similar increases in PETCO2 levels during a graded
exercise test in
patients with
coronary artery disease, which may be associated with an improvement in ventilatory
efficiency and
cardiorespiratory fitness.