title: Safety of strength training in premenopausal women: musculoskeletal injuries from a two-year randomized trial.
abstract: OBJECTIVE
  The health benefits of strength training must be weighed against risks, including injuries. A prior study observed 4.2 injuries that limited usual activities for a day per 1000 strength training sessions among men and women. The analysis herein explores the incidence rates of musculoskeletal injuries from strength training in women.
  
  
  METHODS
  Randomized controlled trial. SETTING; Free-living community.
  
  
  METHODS
  A total of 163 injury-free, overweight, sedentary, premenopausal women aged 25 to 44 years.
  
  
  METHODS
  Two years of strength training (n = 81) or standard care (n = 82). The intervention followed published guidelines (U.S. Department of Health and Human Services) with hypothesized injury prevention strategies.
  
  
  METHODS
  An injury survey was administered at years 1 and 2. Injury was defined as physical activity or strength training associated injuries that limited daily activities for 1 week or more. Denominators for rate calculation were accelerometer-measured physical activity and strength training attendance (strength training only). The between-group probability of injuries was assessed using generalized estimating equations.
  
  
  RESULTS
  Injury incidence rates were higher in strength training compared with standard care. In strength training, the injury rates were 3.6 per 1000 strength training sessions (95% confidence interval: 2.5-4.8 per 1000) for physical activity-related injuries, and 2.6 per 1000 (95% confidence interval: 1.5-3.6 per 1000) for strength training-related injuries.
  
  
  CONCLUSIONS
  Injury rates varied by definition and denominator. Strength training had lower injury rates than previously reported, providing preliminary support for the prevention strategies. The finding of strength training injuries underscores the need for balancing the benefits against the potential risks of this exercise modality.
authors.affiliation: Department of Physical Therapy and Athletic Training Northern Arizona University, Flagstaff, Arizona 86011, USA. meghan.warren@nau.edu
authors.forename: Meghan
authors.initials: M
authors.lastname: Warren
authors.forename: Kathryn H
authors.initials: KH
authors.lastname: Schmitz
mesh_terms: D000054:Acceleration; D000328:Adult; D001823:Body Composition / Q000502:physiology; D015331:Cohort Studies; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D015994:Incidence; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000293:injuries / Q000502:physiology*; D009141:Musculoskeletal System / Q000293:injuries*; D017697:Premenopause / Q000502:physiology*; D055070:Resistance Training / Q000379:methods; D012307:Risk Factors; D014891:Weight Lifting / Q000293:injuries / Q000502:physiology*