Objective: Exercise capacity strongly predicts survival and aerobic interval training (AIT) increases peak oxygen uptake effectively in cardiac patients. Usual care in Norway provides exercise training at the hospitals following myocardial infarction (MI), but the effect and actual intensity of these rehabilitation programmes are unknown.
Design: Randomized controlled trial.
Setting: Hospital cardiac rehabilitation.
Subjects: One hundred and seven patients, recruited two to 12 weeks after MI, were randomized to usual care rehabilitation or treadmill AIT.
Interventions: Usual care aerobic group exercise training or treadmill AIT as 4 × 4 minutes intervals at 85-95% of peak heart rate. Twice weekly exercise training for 12 weeks.
Main measures: The primary outcome measure was peak oxygen uptake. Secondary outcome measures were endothelial function, blood markers of cardiovascular disease, quality of life, resting heart rate, and heart rate recovery.
Results: Eighty-nine patients (74 men, 15 women, 57.4 ± 9.5 years) completed the programme. Peak oxygen uptake increased more (P = 0.002) after AIT (from 31.6 ± 5.8 to 36.2 ± 8.6 mL·kg(-1)·min(-1), P < 0.001) than after usual care rehabilitation (from 32.2 ± 6.7 to 34.7 ± 7.9 mL·kg(-1)·min(-1), P < 0.001). The AIT group exercised with significantly higher intensity in the intervals compared to the highest intensity in the usual care group (87.3 ± 3.9% versus 78.7 ± 7.2% of peak heart rate, respectively, P < 0.001). Both programmes increased endothelial function, serum adiponectin, and quality of life, and reduced serum ferritin and resting heart rate. High-density lipoprotein cholesterol increased only after AIT.
Conclusions: AIT increased peak oxygen uptake more than the usual care rehabilitation provided to MI patients by Norwegian hospitals.