Usefulness of the 6-minute walk test and the 200-metre fast walk test to individualize high intensity interval and continuous exercise training in coronary artery disease patients after acute coronary syndrome: a pilot controlled clinical study

Objective: To study the effects of three individualized exercise training prescriptions using either a percentage of maximal heart rate (HR), maximal 6-minute walk test (6MWT) HR, or maximal 200-metre fast walk test (200-mFWT) HR, on walking performance and exercise capacity in coronary artery disease (CAD) patients.

Design: Controlled clinical study.

Participants: Twenty-seven outpatients enrolled in a rehabilitation programme after an acute coronary syndrome.

Setting: Cardiac rehabilitation unit.

Interventions: Three groups: (A): moderate intensity continuous exercise (MICE) at 70% of the maximal HR of the graded maximal exercise test (n = 10); (B): MICE at the maximal 6MWT HR (n = 8); (C): high intensity interval training (HIIT) based on the 6MWT and the 200-mFWT maximal HR (n = 9). Group B and C performed walk tests every 2 weeks, to readjust training HR (THR) if needed.

Measures: 6MWT and 200-mFWT performances, peak VO₂ and peak power (Pmax).

Results: 6MWT and 200-mFWT performances improved significantly and similarly in all groups (P < 0.05). Peak VO₂ improved significantly in all groups (P < 0.05), this improvement being higher in group C (HIIT) versus A (P < 0.05). Group B was closer to the recommended THR during exercise sessions compared to group A.

Conclusion: This pilot study showed that using the 6MWT and 200-mFWT HR to individualize MICE or HIIT prescription is feasible in CAD patients, and could lead them closer to THR objective, to similar improvements in walking performance, and greater peak VO₂ increase for HIIT. Future randomised studies should investigate long-term effects of programmes prescribed from walk tests HR, especially for HIIT modality.