“…There is an increasing body of evidence to suggest that regular vigorous physical activity may be beneficial in preventing recurrence of myocardial infarctions (Hackett & Cassem, 1978;Morris, Everitt, Pollard, Chave, & Semmence, 1980), and in rehabilitation following myocardial infarction (Blair, 1982). Although some studies (e.g., Sedgwick, Brotherhood, Harris-Davidson, Taplin, & Thomas, 1980) dispute the relationship between regular exercise and decreased likelihood of heart disease, others (e.g., Blair et al, 1983) have found a relationship between the adoption of exercise and the reduction of heartdisease risk factors, and it is generally accepted that exercise has an important role to play in heart-disease prevention and rehabilitation (Blair, 1982;Carleton & Lasater, 1983;Thomas, 1979).…”