Acute Response and Adaptation of Physiological and Conceptual Appetite Indices and Body Weight to Aerobic Training in Obese Middle-Aged and Elderly Women

Because of a compensatory appetite increase in response to exercise energy expenditure, the net weight loss is less than expected values in weight control interventions. Therefore, we investigated the acute response and adaptation of physiological and conceptual appetite indices and body weight to aerobic training in obese middle-aged and elderly women. Body weight, appetite, plasma glucose, insulin and ghrelin were measured before and after an aerobic exercise session following to a breakfast meal at baseline and after (four measurements) eight weeks of aerobic training (3 sessions/week by expending ~500 calories at 50% of GXT’s exhaustion HR) in 26 sedentary women (weight: 92.58 ± 36.9 kg, age: 56.19 ± 7.3 yrs and VO2max: 32.07 ± 2.78 Lit/min) were assigned into experimental and control groups. Independent and paired t-test, and analysis of variance with repeated measures were used to analyze the data. Although body weight in experimental groups was decreased after aerobic training (P=0.001), however; it was elevated from first to second and also from third to fourth measurements in both groups (P<0.05). Before the training period, plasma ghrelin was elevated after breakfast and an exercise session in the experimental group (P=0.023), however, it was decreased in the control (only served breakfast) group (P=0.001). In both experimental and control groups, insulin (P=0.001) and glucose (P=0.003) increased, while hunger decreased (P=0.001). After the training period, the satiety score increased significantly only in the experimental group (P=0.018). Acute response in the experimental group increased for glucose (P<0.05) and decreased for ghrelin, insulin and hungry (P<0.05). However, in the control group, acute glucose and insulin response increased (P<0.05), but ghrelin and starvation decreased (P<0.05). Training-induced fasting hungry elevation failures the fully achievement to net weight loss expected form training, which suggests including lesser calorie foods in the breakfast meal. Additionally, considering the acute increase of food satiety quotient by exercise, it seems the breakfast meal should be postponed for the end of exercise session.