title: Influence of an interpersonal laboratory stressor on youths' choice to be physically active.
abstract: OBJECTIVE
  To determine whether interpersonal stress reduces youths' motivation to exercise in a laboratory setting.
  
  
  METHODS
  Physical activity and sedentary behavior were measured in boys and girls across a control day, after reading children's magazines, and on a stress day, after giving a videotaped speech. For one analysis, children were divided into low (n = 12) and high (n = 13) heart-rate reactivity groups based on changes in heart rate to stress. In a second analysis, children were divided into low and high perceived level of stress based on changes in perceived stress. To determine differences in choice of exercise or sedentary behavior across the control and stress conditions, subjects chose either to exercise for progressively longer periods to earn a monetary reinforcer or to engage in a high-rated sedentary behavior.
  
  
  RESULTS
  The choice to exercise was influenced by stress reactivity differently in the stress and control conditions. Low heart-rate reactive children participated in similar (p > 0.50) amounts of exercise on the stress and control days, but high heart-rate reactive children participated in less (p < 0.01) exercise (22.0 +/- 2.5 vs. 26.3 +/- 2.2 minutes) on the stress than control days. When grouped by change in perceived stress, there were no group differences, but subjects exercised longer (p < 0.01) on the control day than the stress day.
  
  
  CONCLUSIONS
  Interpersonal stress decreased exercise in children susceptible to interpersonal stress. Stress-induced alterations in health behaviors may lead to weight gain in children.
authors.affiliation: Division of Behavioral Medicine, Department of Pediatrics, University at Buffalo School of Medicine and Biomedical Sciences, Buffalo, New York 14214-3000, USA. roemmich@buffalo.edu
authors.forename: James N
authors.initials: JN
authors.lastname: Roemmich
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Gurgol
authors.forename: Leonard H
authors.initials: LH
authors.lastname: Epstein
mesh_terms: D000704:Analysis of Variance; D015992:Body Mass Index; D002648:Child; D002652:Child Behavior / Q000502:physiology* / Q000523:psychology*; D002755:Choice Behavior; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology / Q000523:psychology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009765:Obesity / Q000209:etiology / Q000523:psychology; D013315:Stress, Psychological / Q000503:physiopathology / Q000523:psychology; D013997:Time Factors