Canadian researchers reported at OBESITY 2011 that moms of children under 6 years of age get less physical activity than those who do not have children at home. This study found these women averaged 6.38 minutes less of moderate to vigorous intensity excercise each day–or about 45 minutes per week, almost one-third less than the recommended 150 weekly minutes!
PositiveTip: Dad, step-up and do your wife a favor: watch the kid(s) while she exercises! Short of that, Mom: bundle-up the children and take them with you for a brisk walk.