Post-exercise V̇O2 kinetics and V̇O2 recovery delay (RD) are clinical prognostic markers in cardiac patients, but have not been studied after exercise training in patients with coronary heart disease (CHD). We aimed to compare the effects of 12-weeks moderate-intensity continuous exercise training (MICET), low volume high-intensity interval training (LV-HIIT), or combined MICET/HIIT on O2 deficit, post-exercise V̇O2 kinetics, O2 debt and V̇O2 recovery delay (RD) in patients with CHD.

Methods Patients with CHD were randomised in MICET, LV-HIIT or combined MICET/HIIT group for 12 weeks. Cardiopulmonary exercise test (CPET) parameters were assessed, and key exercise variables were calculated during and after exercise. CPET post-exercise kinetics time constant (r) (for V̇O2, V̇CO2, V̇E and HR), O2 deficit, O2 debt and V̇O2 recovery delay (RD) were calculated before and after training.

Results A significant time effect (training) for r V̇O2 (min) (p<0.05) was shown for all groups. Shorter r V̇O2 values with small effect size (ES: 0.21 to 0.4) were noted for the combined MICET/HIIT and MICET groups. A significant time effect (p<0.01) was noted for O2 debt that was increased after training (ES: 0.1 to 0.47). No significant statistical effect was shown for V̇O2 RD and r V̇CO2, r V̇E, r HR and O2 deficit in all groups.

Conclusions In patients with CHD, exercise training improved post-exercise V̇O2 kinetic and the O2 debt, with a higher impact of exercise dose (combined MICET/HIIT). Exercise training did not improved the V̇O2 RD or other τ CPET recovery variables in CHD patients.

The authors have declared no competing interest.

NCT03414996 NCT02048696 NCT03443193

The study was funded by the Mirella and Lino Saputo Research Chair in Cardiovascular Diseases and the Prevention of Cognitive Decline from University of Montreal at the Montreal Heart Institute, the Montreal Heart Institute Foundation and the EPIC Center Foundation.

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Ethics committee/IRB of the Montreal Heart Instiute gave ethical approval for this work

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Funding: The study was funded by the Mirella and Lino Saputo Research Chair in Cardiovascular Diseases and the Prevention of Cognitive Decline from Université de Montréal at the Montreal Heart Institute, the Montreal Heart Institute Foundation and the EPIC Center Foundation.

Competing Interests: None

Clinical protocols: (ClinicalTrials.gov identifier numbers: NCT03414996, NCT02048696, NCT03443193)

Data Availability Statement: none

All data produced in the present work are contained in the manuscript