title: Physical activity in cancer survivors: a field in motion.
abstract: Physical activity (PA) is an important health behavior in almost any population but it may be particularly helpful for cancer survivors.
  
  
  OBJECTIVE
  To introduce this special issue on PA in cancer survivors and to provide a summary of its important contributions to the field.
  
  
  METHODS
  A brief historical review of PA research in cancer survivors followed by a narrative review of the articles published in this special issue.
  
  
  RESULTS
  This special issue contains 13 original articles reporting 15 studies on PA in cancer survivors. Just over half of the studies focus on breast cancer survivors, whereas the remainder focus on understudied cancer survivor groups such as lung, ovarian, colorectal, prostate, hematologic, and pediatric. Moreover, a majority of the studies focus on the survivorship phase of the cancer continuum. Perhaps the most distinctive feature of this special issue is the number of studies focusing on the determinants of PA. Taken together, the 13 articles make significant contributions in four areas: (1) randomized controlled trials of PA interventions with supportive care endpoints, (2) observational studies on the determinants of PA, (3) observational studies on the 'determinants of PA determinants', and (4) studies on methodological and feasibility issues related to conducting PA trials.
  
  
  CONCLUSIONS
  PA research is making an important contribution to the health and well-being of cancer survivors across the entire cancer control continuum. This special issue builds on this momentum and provides the single largest collective contribution of knowledge to date in the field of PA in cancer survivors.
authors.forename: Kerry S
authors.initials: KS
authors.lastname: Courneya
mesh_terms: D005240:Feasibility Studies; D006293:Health Promotion; D006801:Humans; D009043:Motor Activity; D009369:Neoplasms / Q000453:epidemiology*; D011788:Quality of Life; D013177:Sports; D017741:Survivors / Q000706:statistics & numerical data*