title: Effects of continuous versus intermittent exercise, obesity, and gender on growth hormone secretion.
abstract: BACKGROUND
  Obesity attenuates spontaneous GH secretion and the GH response to exercise. Obese individuals often have low fitness levels, limiting their ability to complete a typical 30-min bout of continuous exercise. An alternative regimen in obese subjects may be shorter bouts of exercise interspersed throughout the day.
  
  
  OBJECTIVE
  The objective of the study was to examine whether intermittent and continuous exercise interventions evoke similar patterns of 24-h GH secretion and whether responses are attenuated in obese subjects or affected by gender.
  
  
  METHODS
  This was a repeated-measures design in which each subject served as their own control.
  
  
  METHODS
  This study was conducted at the University of Virginia General Clinical Research Center.
  
  
  METHODS
  Subjects were healthy nonobese (n = 15) and obese (n = 14) young adults.
  
  
  METHODS
  Subjects were studied over 24 h at the General Clinical Research Center on three occasions: control, one 30-min bout of exercise, and three 10-min bouts of exercise.
  
  
  METHODS
  Twenty-four hour GH secretion was measured.
  
  
  RESULTS
  Compared with unstimulated 24-h GH secretion, both intermittent and continuous exercise, at constant exercise intensity, resulted in severalfold elevation of 24-h integrated serum GH concentrations in young adults. Basal and pulsatile modes of GH secretion were attenuated both at rest and during exercise in obese subjects.
  
  
  CONCLUSIONS
  The present data suggest that continuous and intermittent exercise training should be comparably effective in increasing 24-h GH secretion.
authors.affiliation: Department of Human Services, University of Virginia, Charlottesville, Virginia 22904, USA. alw2v@virginia.edu
authors.forename: Arthur
authors.initials: A
authors.lastname: Weltman
authors.forename: Judy Y
authors.initials: JY
authors.lastname: Weltman
authors.forename: Dee Dee
authors.initials: DD
authors.lastname: Watson Winfield
authors.forename: Kirsten
authors.initials: K
authors.lastname: Frick
authors.forename: James
authors.initials: J
authors.lastname: Patrie
authors.forename: Petra
authors.initials: P
authors.lastname: Kok
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Keenan
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Gaesser
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Veldhuis
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D003627:Data Interpretation, Statistical; D015444:Exercise / Q000502:physiology*; D005260:Female; D006207:Half-Life; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009765:Obesity / Q000097:blood / Q000378:metabolism*; D010809:Physical Fitness / Q000502:physiology*; D012146:Rest / Q000502:physiology; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D019382:Human Growth Hormone; D019344:Lactic Acid
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