Energy cost of physical activity throughout pregnancy and the first year postpartum in Dutch women with sedentary lifestyles.

Basal metabolic rate (BMR), activity pattern, and energy costs of some daily activities were measured in 25 Dutch women throughout pregnancy and the first year postpartum. Physical activity index (PAI), which refers to daily energy expenditure expressed as a multiple of BMR, was calculated from activity-pattern data and activity costs. Mean PAIs (+/- SD) throughout pregnancy, during the first 6 mo postpartum, and at 1 y postpartum were 1.48 +/- 0.08, 1.49 +/- 0.07, and 1.53 +/- 0.10 X BMR, respectively. Because measured BMR at 1 y postpartum was 1440 +/- 168 kcal/d, costs for physical activity in pregnancy and the first 6 mo postpartum were, respectively, approximately 70 and approximately 50 kcal/d lower than at 1 y postpartum. For women with sedentary lifestyles the energy saved during pregnancy and lactation because of decreased physical activity and decreased costs of activities will be limited.