Maintaining physical activity among older adults: 24-month outcomes of the Keep Active Minnesota randomized controlled trial

ObjectiveTo evaluate the efficacy at 6-, 12-, and 24-month follow-up of Keep Active Minnesota (KAM), a telephone and mail-based intervention designed to promote physical activity (PA) maintenance among currently active adults age 50 to 70.MethodParticipants who reported having recently increased their MVPA to a minimum of 2d/wk, 30 min/bout, (N = 1049) were recruited in 2004 and 2005 from one large managed care organization in Minnesota, and randomly assigned to either treatment (KAM; N = 523), or Usual Care (UC; N = 526) with PA assessed using the CHAMPS questionnaire, and expressed as kcal/wk energy expenditure.ResultsWe find a sustained, significant benefit of the intervention at 6, 12 and 24 months. kcal/wk expenditure in moderate or vigorous activities was higher at 6 (p < .03, Cohen's d6m = .16), 12 (p < .04, d12m = .13) and 24 months (p < .01, d24m = .16) for KAM participants, compared to UC participants.ConclusionsThe KAM telephone- and mail-based PA maintenance intervention was effective at maintaining PA in both the short-term (6 months) and longer-term (12 and 24 months) relative to usual care.