Relationship between physical activity and mental health in women after childbirth: a cross-sectional exploratory study

BACKGROUND: Physical activity (PA) is recommended for women after childbirth. However, it is unknown whether PA, such as housework and child-rearing, is associated with mental health. This study aimed to measure daily PA in women 2 months postpartum as well as investigate the relationship between daily PA and mental health. METHODS: In this cross-sectional quantitative exploratory study conducted between September 2017 and May 2018, 110 women were approached for participation. Mental health was evaluated using the General Health Questionnaire-28, and PA measurements were performed using accelerometers that the participants wore for 2 days. Welch’s t-test and linear regression analysis were performed to assess the relationship between PA and mental health. RESULTS: This study included 99 participants. The mean amount of daily activities from housework and child-rearing was 3.21 ± 1.14 metabolic equivalent of tasks (METs)-h/day and that of time spent sitting was at least 7.5 h/12.5 h. PA time spent in light child-rearing and housework activities was significantly longer among multiparous women than among primiparous women (t = − 3.41). PA time comprising the duration of moderate (3 METs) or more vigorous PA was 73 min/day. No significant relationship between mental health and PA was observed. However, the amount of daily activities tended to increase with an improvement in mental health. The amount of daily activities exceeded 3 METs-h/day regardless of the mental health status. CONCLUSIONS: No significant relationship was found between the amount of daily activities and mental health. The former increased as the latter improved. The amount of daily activities met the standard recommended by the World Health Organization, regardless of the mental health status.