Post-coronary rehabilitation and risk factors, with special reference to diet

Volunteers were randomly allocated to high intensity exercise (HIE, n = 17, added energy expenditure, 254 progressing to 761 kJ . day-1) and light intensity exercise (LIE, n = 13, < 76 kJ . day-1) programs for a period of one year, commencing 3-12 months after myocardial infarction. Dietary behaviour (7-day records), activity levels (diary records of prescribed activity) and body composition (skinfold readings) were noted at the beginning and end of the study. Both subject groups initially had a low level of energy expenditure (approximately 9.4 MJ . day-1) and a diet relatively low in animal fat. The HIE group showed no significant changes of energy intake, body composition, or blood lipids over the year of observation. In contrast, the LIE group reported a decrease in both energy intake (1.45 MJ . day-1, P < 0.05) and the intake of most individual dietary constituents. It also showed a decrease of triglyceride (P < 0.05), but a suggestion of an increase of subcutaneous fat (triceps, P < 0.05). The HIE program does not confer any necessary advantage of body composition or serum lipid levels, but it does allow a larger food intake. It may thus be of particular value for patients who find adherence to low energy or low cholesterol diets irksome.