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

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 246min/week compared with 46 to 156min/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.