UK mothers with children aged four and under get less than 20 minutes of moderate-to-vigorous physical activity every day, research suggests.
The study also found less than half of mothers meet the recommended levels of exercise, regardless of the age of their children.
Results also showed those with multiple children engaged in lower amounts of daily moderate-to-vigorous physical activity compared to those with one child.
Based on their findings, published in the journal Plos One, the researchers said efforts should be made to help mothers take part in high-intensity physical activity.
Rachel Simpson, a PhD student at the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge, said: “There are clear benefits, both short term and long term, from doing more physical activity, particularly if it increases your heart rate.
“But the demands of being a mother can make it hard to find the time.
“We need to consider ways not only to encourage mums, but to make it as easy as possible for busy mums, especially those with younger children, to increase the amount of higher intensity physical activity they do.”
Physical activity is associated with a wide range of health benefits – from lowering the risk of type 2 diabetes and heart disease to maintaining a healthy weight and better mental health.
It is recommended that adults should do at least 150 minutes of moderate intensity activity – such as brisk walking, riding a bike, dancing, pushing a lawn mower or hiking – a week, or 75 minutes of vigorous intensity activity – such as running, swimming, walking up the stairs, or aerobics – a week.
A team of researchers at the universities of Cambridge and Southampton analysed data from 848 women, aged between 20 and 32, who were recruited between 1998 and 2002 and followed for several years.
They were given accelerometers to assess their levels of activity.
Women with school-aged children did around 26 minutes of daily moderate-to-vigorous physical activity, while those with children aged four years or under managed around 18 minutes per day.
Meanwhile, mothers with more than one child managed only around 21 minutes of daily moderate-to-vigorous physical activity.
But by contrast, mothers with multiple children under five years of age were found to do more light-intensity activity than those with children of school age.
Professor Keith Godfrey, from the MRC Lifecourse Epidemiology Centre and the NIHR Southampton Biomedical Research Centre, said: “It is perhaps not unexpected that mothers who have young children or several children engage in less intense physical activity, but this is the first study that has quantified the significance of this reduction.
“More needs to be done by local government planners and leisure facility providers to support mothers in engaging in physical activity.”