title: Effect of brief daily exercise on headache among adults--secondary analysis of a randomized controlled trial.
abstract: OBJECTIVE
  This paper investigates secondary outcomes (headache) in a randomized controlled trial with         physical exercise among office workers with neck/shoulder pain.
  
  
  METHODS
  A total of 198 office workers with frequent         neck/shoulder pain were randomly allocated to either one of two intervention groups (10 weeks of resistance training         with elastic tubing for 2 or 12 minutes per day, 5 times a week) or the control group, which received weekly health         information. Secondary outcomes included changes in frequency, intensity, and duration of headache after ten weeks.
  
  
  RESULTS
  Compared with the control group, headache frequency decreased in the 2- and 12-minute intervention groups         [0.64 days/week (95% confidence interval [95% CI]) 0.23-1.0) and 0.79 days/week (95% CI 0.37-1.2),         corresponding to a 43% and 56% decrease from baseline, respectively]. Intensity and duration of the remaining headaches         were unaffected.
  
  
  CONCLUSIONS
  Two minutes of daily resistance training for ten weeks reduces headache frequency among         office workers with neck/shoulder pain. The vast number of adult workers suffering from one or two days of weekly         headaches and who could potentially comply with and benefit from brief exercise programs stresses the applicability of         our findings.
authors: National Research Centre for the Working Environment, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. lla@arbejdsmiljoforskning.dk
authors: Lars L
authors: LL
authors: Andersen
authors: Ole S
authors: OS
authors: Mortensen
authors: Mette K
authors: MK
authors: Zebis
authors: Rigmor H
authors: RH
authors: Jensen
authors: Otto M
authors: OM
authors: Poulsen