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OBJECTIVE: To investigate whether time interval between meal and exercise alters the balance of substrate oxidation during an exercise bout. HYPOTHESIS: Exercise performed 3-h after meal induces a higher rate of lipid oxidation than when performed only 1-h after meal. RESEARCH METHODS AND PROCEDURES: Eight overweight and obese postmenopausal women (age: 57.472.4 y; BMI: 31.872.1 kg m À2 ; %FAT: 42.771.2%, mean7s.e.m.) performed two sessions of exercise training at an intensity corresponding to their ' crossover' point of substrate oxidation (COP ox ). One session was held 1 h after a standardized meal and the other, 3 h after an identical meal on another day. Substrate oxidation was evaluated by indirect calorimetry. Hormonal responses were investigated during exercise. RESULTS: Respiratory exchange ratio values were lower in the 3-h condition, showing higher lipid oxidation during exercise (average difference þ 38.972.7 mg min À1 ; Po0.001), while mean energy expenditure did not differ. Basal heart rate was reduced in the 3 h compared with the 1-h condition (7875 vs 8775 bpm; Po0.05). Glycemia, lactatemia and insulinemia were reduced when exercise was performed 3 h after meal (Po0.05). DISCUSSION: When exercise is performed 3 h after meal at an intensity corresponding to the COP ox , metabolic and hormonal responses are similar to those targeted during the submaximal exercise test performed at fast that we previously proposed to individualize exercise training in the obese.

Resting and exercise cardiac function, skeletal muscle oxygenation and whole-body aerobic exercise capacities were evaluated prospectively in cardiac symptom-free HIV men receiving antiretroviral therapies and in healthy controls matched for age, physical activity, smoking and body surface area. HIV patients showed resting cardiac dysfunction, altered cardiac responses to exercise and depressed exercise tolerance. Exercise stroke volume kinetics and muscle oxygenation were impaired in HIV patients, especially in those with resting diastolic dysfunction.

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