title: A new approach to physical activity maintenance: rationale, design, and baseline data from the Keep Active Minnesota Trial.
abstract: BACKGROUND
  Since many individuals who initiate physical activity programs are highly likely to return to a sedentary lifestyle, innovative strategies to efforts to increase the number of physically active older adults who successfully maintain beneficial levels of PA for a substantial length of time are needed.
  
  
  METHODS
  The Keep Active Minnesota Trial is a randomized controlled trial of an interactive phone- and mail-based intervention to help 50-70 year old adults who have recently increased their physical activity level, maintain that activity level over a 24-month period in comparison to usual care. Baseline, 6, 12, and 24 month measurement occurred via phone surveys with kilocalories expended per week in total and moderate-to-vigorous physical activity (CHAMPS Questionnaire) as the primary outcome measures. Secondary outcomes include hypothesized mediators of physical activity change (e.g., physical activity enjoyment, self-efficacy, physical activity self-concept), body mass index, and depression. Seven day accelerometry data were collected on a sub-sample of participants at baseline and 24-month follow-up.
  
  
  CONCLUSIONS
  The Keep Active Minnesota study offers an innovative approach to the perennial problem of physical activity relapse; by focusing explicitly on physical activity maintenance, the intervention holds considerable promise for modifying the typical relapse curve. Moreover, if shown to be efficacious, the use of phone- and mail-based intervention delivery offers potential for widespread dissemination.
authors.affiliation: HealthPartners Research Foundation, Minneapolis, MN, USA. nancy.e.sherwood@healthpartners.com
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Sherwood
authors.forename: Brian C
authors.initials: BC
authors.lastname: Martinson
authors.forename: A Lauren
authors.initials: AL
authors.lastname: Crain
authors.forename: Marcia G
authors.initials: MG
authors.lastname: Hayes
authors.forename: Nicolaas P
authors.initials: NP
authors.lastname: Pronk
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: O'Connor
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment; D006293:Health Promotion / Q000379:methods*; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D008991:Monitoring, Physiologic / Q000379:methods; D010349:Patient Compliance / Q000706:statistics & numerical data; D010809:Physical Fitness; D011336:Probability; D012016:Reference Values; D011795:Surveys and Questionnaires