title: Sex differences in pulmonary oxygen uptake kinetics in obese adolescents.
abstract: OBJECTIVE
  To determine whether sex differences exist in the pulmonary oxygen uptake (VO2) uptake on-kinetic response to moderate exercise in obese adolescents. We also examined whether a relationship existed between the VO2 on-transient response to moderate intensity exercise, steady-state VO2, and peak VO2 between obese male and female adolescents.
  
  
  METHODS
  Male (n = 12) and female (n = 28) adolescents completed a graded exercise test to exhaustion on a treadmill. Data from the initial 4 minutes of treadmill walking were used to determine the time constant.
  
  
  RESULTS
  The time constant was significantly different (P = .001) between obese male and female adolescents (15.17 ± 8.45 seconds vs 23.07 ± 8.91 seconds, respectively). No significant relationships were observed between the time constant and variables of interest in either sex.
  
  
  CONCLUSIONS
  Sex differences exist in VO2 uptake on-kinetics during moderate exercise in obese adolescents, indicating an enhanced potential for male subjects to deliver and/or use oxygen. It may be advantageous for female subjects to engage in a longer warm-up period before the initiation of an exercise regimen to prevent an early termination of the exercise session.
authors.affiliation: Department of Health and Human Performance, School of Education, Virginia Commonwealth University, Richmond, VA. Electronic address: francorl@vcu.edu.
authors.forename: R Lee
authors.initials: RL
authors.lastname: Franco
authors.affiliation: Department of Health and Human Performance, School of Education, Virginia Commonwealth University, Richmond, VA.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Bowen
authors.affiliation: Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL.
authors.forename: Ross
authors.initials: R
authors.lastname: Arena
authors.affiliation: Department of Health and Human Performance, School of Education, Virginia Commonwealth University, Richmond, VA.
authors.forename: Stacey H
authors.initials: SH
authors.lastname: Privett
authors.affiliation: Department of Health and Human Performance, School of Education, Virginia Commonwealth University, Richmond, VA.
authors.forename: Edmund O
authors.initials: EO
authors.lastname: Acevedo
authors.affiliation: Division of Endocrinology and Metabolism, Departments of Internal Medicine and Pediatrics, School of Medicine, Virginia Commonwealth University, Richmond, VA.
authors.forename: Edmond P
authors.initials: EP
authors.lastname: Wickham
authors.affiliation: Department of Health and Human Performance, School of Education, Virginia Commonwealth University, Richmond, VA.
authors.forename: Ronald K
authors.initials: RK
authors.lastname: Evans
mesh_terms: D000293:Adolescent; D002648:Child; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology; D006801:Humans; D008297:Male; D009765:Obesity / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D012737:Sex Factors