title: Effects of an acute bout of aerobic exercise on immediate and subsequent three-day food intake and energy expenditure in active and inactive pre-menopausal women taking oral contraceptives.
abstract: This study examined the effects of an acute bout of exercise of low-intensity on food intake and energy expenditure over four days in women taking oral contraceptives. Twenty healthy, active (n = 10) and inactive (n = 10) pre-menopausal women taking oral contraceptives completed two conditions (exercise and control), in a randomised, crossover fashion. The exercise experimental day involved cycling for one hour at an intensity equivalent to 50% of maximum oxygen uptake and two hours of rest. The control condition comprised three hours of rest. Participants arrived at the laboratory fasted overnight; breakfast was standardised and an ad libitum pasta lunch was consumed on each experimental day. Participants kept a food diary to measure food intake and wore an Actiheart to measure energy expenditure for the remainder of the experimental days and over the subsequent 3 days. There was a condition effect for absolute energy intake (exercise vs.
  
  
  METHODS
  3363 ± 668 kJ vs. 3035 ± 752 kJ; p = 0.033, d = 0.49) and relative energy intake (exercise vs.
  
  
  METHODS
  2019 ± 746 kJ vs. 2710 ± 712 kJ; p <0.001, d = -1.00) at the ad libitum lunch. There were no significant differences in energy intake over the four days in active participants and there was a suppression of energy intake on the first day after the exercise experimental day compared with the same day of the control condition in inactive participants (mean difference = -1974 kJ; 95% CI -1048 to -2900 kJ, p = 0.002, d = -0.89). There was a group effect (p = 0.001, d = 1.63) for free-living energy expenditure, indicating that active participants expended more energy than inactive participants during this period. However, there were no compensatory changes in daily physical activity energy expenditure. These results support the use of low-intensity aerobic exercise as a method to induce a short-term negative energy balance in inactive women taking oral contraceptives.
authors: Department of Physiology, School of Medicine, Faculty of Health Sciences, Trinity College Dublin, D2, Ireland. Electronic address: Borgespj@tcd.ie.
authors: Joel
authors: J
authors: Rocha
authors: Food and Nutrition Group, Sheffield Business School, Sheffield Hallam University, S1 1WB, UK.
authors: Jenny
authors: J
authors: Paxman
authors: Biomedical Research Centre, Faculty of Health and Wellbeing, Sheffield Hallam University, S1 1WB, UK.
authors: Caroline
authors: C
authors: Dalton
authors: Academy of Sport and Physical Activity, Faculty of Health and Wellbeing, Sheffield Hallam University, S10 2BP, UK.
authors: Edward
authors: E
authors: Winter
authors: Academy of Sport and Physical Activity, Faculty of Health and Wellbeing, Sheffield Hallam University, S10 2BP, UK.
authors: David
authors: D
authors: Broom
mesh_terms: D056044:Actigraphy; D000328:Adult; D001066:Appetite; D003276:Contraceptives, Oral; D015930:Diet Records; D004435:Eating; D002149:Energy Intake; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D005215:Fasting; D005260:Female; D006801:Humans; D062407:Meals; D005082:Physical Exertion; D017697:Premenopause; D012146:Rest / Q000502:physiology*; D057185:Sedentary Behavior; D055815:Young Adult
chemical_list: D003276:Contraceptives, Oral
keywords: Active; Appetite; Exercise; Food intake; Inactive; Oral contraceptives