Exercise-based cardiac rehabilitation increases daily physical activity of patients following myocardial infarction: subanalysis of two randomised controlled trials.

OBJECTIVE: To assess the effects of an exercise-based cardiac rehabilitation programme on daily physical activity levels of patients following myocardial infarction.

DESIGN: Subanalysis of two randomised, prospective controlled trials.

SETTING: Outpatient clinic of a secondary hospital.

PARTICIPANTS: Fifty consecutive patients randomised to the exercise group {n=25; 23 males; mean age 54 [standard deviation (SD) 9] years} or the control group [n=25; 20 males; mean age 58 (SD 9) years].

INTERVENTIONS: The exercise group participated in an 8-week aerobic exercise programme plus usual medical care and follow-up. The control group received usual medical care and follow-up.

MAIN OUTCOME MEASURES: The primary outcome measure was change in time spent undertaking moderate-to-vigorous physical activity per day, assessed by accelerometer over 7 consecutive days. Secondary outcome measures were cardiorespiratory fitness, body mass, and resting blood pressure and heart rate.

RESULTS: Moderate-to-vigorous physical activity levels increased significantly in the exercise group [43.2 (SD 36.3) to 53.5 (SD 31.9) minutes/day, P=0.030], and remained unchanged in the control group [40.8 (SD 26.2) to 36.8 (SD 26.5) minutes/day, P=0.241] from baseline to the end of the programme. Cardiorespiratory fitness increased significantly in the exercise group (mean difference 2.8; 95% of the difference 1.3 to 4.4ml/kg/minute, P=0.001) after the 8-week programme.

CONCLUSIONS: In patients under optimal medication following myocardial infarction, participation in an 8-week exercise-based cardiac rehabilitation programme was found to improve physical activity levels consistent with health-related benefits. Future studies are needed to determine whether the increase in physical activity is maintained in the long term.