title: Behavioral assessment of the reinforcing effect of exercise in women with anorexia nervosa: further paradigm development and data.
abstract: OBJECTIVE
  To use a Progressive Ratio (PR) computerized "work" paradigm to measure course and correlates of exercise motivation in in-patients with Anorexia Nervosa (AN).
  
  
  METHODS
  Sixteen inpatients with AN participated in a PR task assessing the relative reinforcing effect of two different increments of cash versus the opportunity to exercise for upto 30 min, twice; at low weight, and, for n = 10 participants, after weight restoration.
  
  
  RESULTS
  There was a trend toward a higher work for exercise with 2 versus 5 increments of cash as the alternative reinforcer. Exercise breakpoint did not differ between low and normal-weight states. Exercise breakpoint at each time point was correlated with prehospitalization exercise "commitment" (Commitment to Exercise Scale, r = .613, p = .012 at T1; r = .634, p = .049 at T2).
  
  
  CONCLUSIONS
  Patients with AN will work at a PR task for access to even a small amount of exercise. Exercise motivation during hospitalization is correlated with prehospital exercise commitment and does not appear to change consistently with weight restoration.
authors.affiliation: Department of Psychiatry, Columbia University Medical Center, New York State Psychiatric Institute, New York, New York 10032, USA. dk2127@columbia.edu
authors.forename: Diane A
authors.initials: DA
authors.lastname: Klein
authors.forename: Janet E
authors.initials: JE
authors.lastname: Schebendach
authors.forename: Marina
authors.initials: M
authors.lastname: Gershkovich
authors.forename: Lindsay P
authors.initials: LP
authors.lastname: Bodell
authors.forename: Richard W
authors.initials: RW
authors.lastname: Foltin
authors.forename: B Timothy
authors.initials: BT
authors.lastname: Walsh
mesh_terms: D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000175:diagnosis / Q000523:psychology*; D015992:Body Mass Index; D001835:Body Weight; D015444:Exercise / Q000523:psychology*; D005260:Female; D006760:Hospitalization; D006801:Humans; D008875:Middle Aged; D009042:Motivation; D009518:New York; D011594:Psychometrics; D012054:Reinforcement, Psychology; D014040:Token Economy; D055815:Young Adult