Effectiveness of a 12-month randomized clinical trial to increase physical activity in multiethnic postpartum women: Results from Hawaii's Nā Mikimiki Projectâ˜

•Compared effectiveness of 2 moderate-to-vigorous physical activity (MVPA) conditions.•Randomized controlled trial recruited 311 postnatal women, followed for 12-months.•Telephone/website intervention was tailored to ethnic minority women with infants.•Tailored condition increased MVPA minutes/week more than standard (p = 0.027).•Mothers with ≥ 2 children increased MVPA more than those with one child (p = 0.016).

ObjectiveFew postpartum ethnic minority women perform leisure-time moderate-to-vigorous physical activity (MVPA). The study tested the effectiveness of a 12-month tailored intervention to increase MVPA in women with infants 2-12 months old.MethodsFrom 2008 to 2011, women (n = 311) with infants (average age = 5.7 months) from Honolulu, Hawaii were randomly assigned to receive tailored telephone calls and access to a mom-centric website (n = 154) or access to a standard PA website (n = 157). MVPA was measured at baseline, 6, and 12 months using self-report and acclerometers.ResultsControlling for covariates, the tailored condition significantly increased self-reported MVPA from an average of 44 to 246 min/week compared with 46 to 156 min/week for the standard condition (p = 0.027). Mothers with ≥ 2 children had significantly greater increases in MVPA in response to the tailored intervention than those with one child (p = 0.016). Accelerometer-measured MVPA significantly increased over time (p = 0.0001), with no condition differences. There was evidence of reactivity to initially wearing accelerometers; the tailored intervention significantly increased MVPA among women with low baseline accelerometer MVPA minutes, but not among those with high minutes (pinteraction = 0.053).ConclusionA tailored intervention effectively increased MVPA over 12 months in multiethnic women with infants, particularly those with more than one child.