EFFECTS OF SHORT-TERM EXERCISE ON APPETITE RESPONSES IN UNRESTRAINED FEMALES

Objective: To examine the short-term effects of exercise and diet comp osition on appetite in unrestrained females. Design: A 2 x 2 repeated measures design study was conducted, with exercise and lunch type as t he repeated factors. Setting: The Human Appetite Research Unit at Leed s University Psychology department. Subjects: 13 unrestrained, normal weight females were recruited from the student and staff population of Leeds University. Interventions: Subjects were assigned to four exper imental treatments in a counterbalanced order. These were a control (n o-exercise) session and an intense (70% VO2 max) exercise session foll owed by a free-selection test lunch consisting of high-fat/low-carbohy drate or low-fat/high-carbohydrate foods. The effects of exercise and lunch type were measured by monitoring energy intake and macronutrient intake during the test lunches only. Visual analogue scales were used to monitor profiles of motivation to eat during the treatments. Resul ts: Subjects did not experience the marked suppression of hunger induc ed by exercise, which is a striking and robust finding in men. Moreove r, unlike men, females rated a range of foods to be more palatable aft er exercise (F(1,12)=8.0, P<0.05). Similar to male subjects, exercise in females had no significant short-term effect on energy or macronutr ient intake. Energy intake was significantly influenced by the fat:car bohydrate composition of the foods available (F(1,12)=64.7, P<0.001), and the short-term energy deficit induced by exercise when followed by low-fat lunch was completely wiped out when exercise was followed by a high-fat lunch (F(1,12)=66.2, P<0.001). Conclusions: These results s how that there are similarities and differences between males and fema les in the appetite response to foods varying in macronutrient composi tion following vigorous exercise. The differences may help to explain why exercise so often produces a disappointing effect on weight contro l in females.