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

Abstract Objective Few 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. Methods From 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. Results Controlling 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 ( p interaction  = 0.053). Conclusion A tailored intervention effectively increased MVPA over 12 months in multiethnic women with infants, particularly those with more than one child.