title: Exercise and negative energy balance in males who perform mental work.
abstract: BACKGROUND
  Although energy expenditure during mental work is not higher than energy expenditure at rest, a stressful mental task is related to an increase in energy intake. It is suggested that mental work produces physiological changes, thereby influencing food intake.
  
  
  OBJECTIVE
  Because physical activity can influence hunger, the aim of the study was to determine if the introduction of an active pause could counteract the negative effects of mental work on energy intake and energy balance.
  
  
  METHODS
  Twelve male students, of normal weight, between 15 and 20 years old were evaluated. All subjects participated in three different sessions realized in a randomized order: (i) without pause = relaxation/mental work/meal; (ii) relaxation pause = mental work/relaxation/meal; and (iii) exercise pause = mental work/exercise/meal. Energy expenditure was measured with indirect calorimetry, energy intake was measured with a cold buffet-type meal of 40 items, and appetite-related sensations were measured with visual analogue scales. The effect of introducing an active pause in energy intake and energy balance was studied.
  
  
  RESULTS
  The introduction of an active pause did not influence energy intake; although, higher appetite-related sensations were observed (16-26 mm on a 150-mm scale; P < 0.05). After accounting for the energy expenditure related to physical activity, a lower energy balance was measured for the exercise pause visit compared with the visit without a pause (-1137 kJ; P < 0.05).
  
  
  CONCLUSIONS
  This study indicates that being active between mental work and a meal could represent a strategy to create a negative energy balance following mental work via an increased energy expenditure and a maintenance of energy intake. Globally, these results could help individuals attain and/or maintain a healthy body weight in a context where mental work is omnipresent.
authors: Department of Kinesiology, University of Montreal, Montreal, QC, Canada; UHC Sainte-Justine Research Center, Montreal, QC, Canada.
authors: V
authors: V
authors: Lemay
authors: V
authors: V
authors: Drapeau
authors: A
authors: A
authors: Tremblay
authors: M-E
authors: ME
authors: Mathieu
mesh_terms: D000293:Adolescent; D000328:Adult; D001066:Appetite / Q000502:physiology; D002153:Calorimetry, Indirect; D004435:Eating; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology; D006801:Humans; D008297:Male; D008606:Mental Processes / Q000502:physiology; D012016:Reference Values; D057185:Sedentary Behavior
keywords: Adolescent; energy balance; exercise; obesity