Interval training based on ventilatory anaerobic threshold improves aerobic functional capacity and metabolic profile: a randomized controlled trial in coronary artery disease patients

Abstract

Background: Exercise training has been an essential component of cardiac rehabilitation. However, it is not known if interval training (IT) based on the ventilatory anaerobic threshold (VAT) could be effective in improving aerobic functional capacity and metabolic profile in patients without or with coronary artery disease (CAD).

Aim: To investigate the effects of an IT program, based-intensity between 70-110% of workload reached at the VAT, on the aerobic functional capacity and metabolic profile of patients with and without CAD.

Design: Randomized controlled trial.

Setting: Outpatients from a cardiac rehabilitation.

Population: A sample was composed of 32 patients with CAD (CAD group) and 32 patients without CAD (noCAD group) that were randomized into a trained or control groups.

Methods: Submaximal cardiopulmonary exercise test on the cycle ergometer and blood samples were realized at baseline and post 16 weeks of IT program. The cardiorespiratory variables were obtained at the VAT level. Trained groups (CAD-T, N.=15; noCAD-T, N.=15) underwent a supervised three-week session IT program (30-40 minutes each exercise session, at the intensity workloads equivalent to %VAT [70-110%]) for 16 weeks.

Results: After 16 weeks of IT program, there were a significant increase of VO(2VAT) and workload in the trained groups (P<0.05), while in the control groups VO(2VAT) and heart rate decreased (P<0.05). Body mass and body index mass decreased in trained groups (P<0.05), and low-density lipoprotein increased only in noCAD group after 16 weeks (P<0.05). The magnitude of the improvement in VO(2VAT) was related to VO(2VAT) (r=-0.57, P<0.05) and workload (r=-0.52, P<0.05) at baseline.

Conclusion: The IT program prescribed with intensities based on VAT improved the aerobic functional capacity and decreased body mass and body index mass loss in patients with and without CAD.

Clinical rehabilitation impact: IT program based on VAT provides new possibilities for cardiac rehabilitation in relation to individualized exercise prescription of the interval training.

Trial registration: ClinicalTrials.gov NCT02313831.