title: Influence of exercise on visceral pain: an explorative study in healthy volunteers.
abstract: OBJECTIVE
  Contradictory results have been found about the effect of different exercise modalities on pain. The aim of this study was to investigate the early effects of aerobic and isometric exercise on different types of experimental pain, including visceral pain, compared to an active control condition.
  
  
  METHODS
  Fifteen healthy subjects (6 women, mean [standard deviation] age 25 [6.5] years) completed 3 interventions consisting of 20 minutes of aerobic cycling, 12 minutes of isometric knee extension and a deep breathing procedure as active control. At baseline and after each intervention, psychophysical tests were performed, including electrical stimulation of the esophagus, pressure pain thresholds and the cold pressor test as a measure for conditioned pain modulation. Participants completed the Medical Outcome Study Short-Form 36 and State-Trait Anxiety Inventory prior to the experiments. Data were analyzed using two-way repeated measures analysis of variance.
  
  
  RESULTS
  No significant differences were found for the psychophysical tests after the interventions, compared to baseline pain tests and the control condition.
  
  
  CONCLUSIONS
  No hypoalgesic effect of aerobic and isometric exercise was found. The evidence for exercise-induced hypoalgesia appears to be not as consistent as initially thought, and caution is recommended when interpreting the effects of exercise on pain.
authors.affiliation: Department of Surgery, Radboud University Medical Centre, Nijmegen, the Netherlands.
authors.forename: Laura Jgm
authors.initials: LJ
authors.lastname: van Weerdenburg
authors.affiliation: Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Aalborg; Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Christina
authors.initials: C
authors.lastname: Brock
authors.affiliation: Mech-Sense, Department of Gastroenterology, Aalborg University Hospital, Aalborg.
authors.forename: Asbjørn Mohr
authors.initials: AM
authors.lastname: Drewes
authors.affiliation: Department of Surgery, Radboud University Medical Centre, Nijmegen, the Netherlands.
authors.forename: Harry
authors.initials: H
authors.lastname: van Goor
authors.affiliation: Department of Surgery, Radboud University Medical Centre, Nijmegen, the Netherlands.
authors.forename: Marjan
authors.initials: M
authors.lastname: de Vries
authors.affiliation: Department of Anesthesiology, Pain and Palliative Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands.
authors.forename: Oliver Hg
authors.initials: OH
authors.lastname: Wilder-Smith
keywords: breathing exercises; motor activity; pain measurement; pain perception