Shaw 1981.

Study characteristics
Methods	Study design: Multicentre RCT (5 sites) Country: USA Dates participants recruited: 1976 Maximum follow‐up: 5 years Participants were randomised after completion of a 6‐week, low‐level exercise programme run‐in period.
Participants	Inclusion criteria: documented MI ≥ 8 weeks but ≤ 3 years before being enrolled. Other eligibility criteria included the ability to exercise at an intensity level ≥ 3 metabolic equivalents (METs) and a supine resting diastolic blood pressure < 100 mmHg. Exclusion criteria: participants were considered ineligible if they had any other significant coexisting CVD or other disease likely to be fatal in the near future, uncontrolled diabetes mellitus, complete heart block with or without ventricular pacemaker, or emotional or physical impairments that would make participation and adherence difficult, or if they were already participants in a formal exercise programme. N randomised: total:651; intervention: 323; comparator: 328 Diagnosis (% of participants): MI: 100% Age (mean ± SD): intervention: 51.5 ± 7.4; comparator: 52.1 ± 7.2 Percentage male: 100% Ethnicity % white: intervention: 93.3%; comparator: 94.4%
Interventions	Intervention: An exercise prescription was developed on the basis of each participant’s multistage graded exercise test (MSET) results. An exercise target heart rate guided the prescription and was determined as 85% of the peak heart rate achieved on the test. This group performed brisk physical activity in the laboratory for 8 weeks, exercising 1 hour per day, 3 days per week. The participants were supervised and underwent continuous ECG monitoring. Each individual exercised for 4 minutes on each of 6 stationary machines with a 2‐minute rest interval between machines. Attainment of the target heart rate was the goal for every 4‐minute exercise period. After 8 weeks, participants exercised in a gymnasium or swimming pool without ECG monitoring, although exercise heart rates were periodically checked. Activities consisted of 15 minutes of continuous jogging, cycling, or swimming, followed by 25 minutes of recreational games. The activities were performed at an intensity level enabling each participant to reach his individually prescribed target heart rate. The men were encouraged to attend 3 sessions per week but in some situations were allowed to exercise on their own. Components: exercise only. Setting: group sessions in centre (“but in some situations were allowed to exercise on their own”). Exercise programme modality: “brisk physical activity” on “stationary machines”. Length of session: 40 min. Frequency: 3 days per week. Intensity: 85% of the peak heart rate. Resistance training included? No Total duration: 8 weeks in the laboratory, followed by regular jogging, cycling, or swimming and recreational games. Co‐interventions: none described. Comparator: Participants in the non‐exercising control group were encouraged to maintain normal routines but not to participate in any regular exercise programme. Co‐interventions: none described.
Outcomes	Total & CHD mortality, non‐fatal MI.
Source of funding	National Heart, Lung, and Blood Institute.
Conflicts of interest	NR
Notes	90% of ET attended 90% of 24 scheduled sessions post‐randomisation, only 48% attending > 50% of sessions at 18 months. 30% of control alleged exercising regularly, on own initiative. At 19 years any protective effect from the programme had decreased over time, but an increase with PWC from the beginning to the end of the trial was associated with a consistent reduction in mortality throughout the 19 years of follow‐up.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Sequence generation not described…."the men were randomly assigned.”
Allocation concealment (selection bias)	Unclear risk	Allocation concealment not described.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	6.5% lost to follow‐up; no description of withdrawals or dropouts.
Selective reporting (reporting bias)	Low risk	All outcomes reported for all time points.