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Beth Lewis hopes to motivate women to exercise at the point in their life when it can be most difficult — during pregnancy and in the months after having a baby.

It's during this stressful time that exercise can have an especially important impact on mental health, her research shows.

Lewis, who runs the Exercise and Mental Health Lab at the University of Minnesota's School of Kinesiology, is researching how effective exercise can be in preventing postpartum depression.

She's also trying to determine the best ways to motivate pregnant women and new moms. We talked to Lewis about her research, how to make exercise "a part of who you are" and the ways moms can fit working out into their unpredictable days.

Q: What has your research using FitBit activity trackers shown so far about new moms, exercise and mental health?

A: We found that higher levels of physical activity related to lower levels of depressive symptoms. If they were exercising more, they had lower levels of postpartum depression. This was among women who either had a history of depression themselves or their mother had a history of depression. So they were at a heightened risk.

Q: Do you have any suggestions for how new moms can fit exercise into their day?

A: They can do it in 10-minute bouts. We just say, fit it in when you can. Usually, people try to do [it in the] mornings when the energy level is maybe a little higher. As you know, as the day goes on, it gets a little bit more unpredictable.

Q: What kind of exercise do you suggest for new moms, and when is it safe to start?

A: Moderate-intensity activity. The most common [choice] was walking. Basically, we were gradually getting them back into exercise. Some health care providers will say you can start exercising within two weeks, others will say to start within six weeks. We had to get health care provider consent for them. So once we got their consent, they started a program gradually.

Q: Your latest research is focusing on another group of women who are at high risk for depression as new moms — not because of their own experience with the illness or family history, but because they are struggling with poverty. Can you explain what you are hoping to find out?

A: We are looking at low-income women, and we're starting this study during pregnancy, at 20 weeks or less. They're randomized [into two groups]. Either we're calling them trying to motivate them to exercise, or they get their usual health care that they would when they're pregnant. And then we're following them, doing the intervention all the way through three months postpartum.

We're taking people who are not depressed and trying to prevent it, given all the stressors.

Q: How do you go about encouraging someone who is pregnant or just had a baby and is facing financial pressures to fit exercise into a life that's already stressful?

A: When I talk to our interventionists about how it's going, they say sometimes it's just not going to work. There's just too much going on, they're worrying about where they're going to live or something like that. But talking about exercise, it doesn't take away that stressor, but it can actually give you the capability to cope.

Q: How do you develop the type of motivators and interventions that you do?

A: It is based on a combination of self-determination theory and motivational interviewing. You try to make exercise a part of who you are: "I am an exerciser, this is what I do." This makes it intrinsically motivating — focusing on how you feel when you're done exercising, how much energy you have during the day.

We found that it's not helpful to tell somebody that exercise is going to help you lose weight or exercise is going to help you reduce your risk of heart disease. It's more about making it a priority because of how it how it makes you feel better, both cognitively in terms of thoughts and stress, and then also energy-wise and enjoyment-wise.

Motivational interviewing is a way that the counselor talks to the participant, having them generate ideas about how they can make it a part of their life and how important it is to them. We have found that if you can make exercise a habit, and make it a part of your day and a part of who you are, that's where you are going to get some long-term success.

Q: Why is this so important?

A: We need low-cost interventions to help prevent postpartum depression. Many health care providers will prescribe antidepressants. It's pretty controversial whether or not they're safe. There's been studies to show that they are, and then there's others that have questioned if they're safe or not. Regardless, I think there's skepticism of women during pregnancy and postpartum to take them.

Also, the effectiveness of them during pregnancy is mixed. There's data to show that women may need higher doses because of the way they are metabolizing the antidepressant during pregnancy. So there's a lot of issues with taking antidepressants.

We also know that only about 10 percent of women who have postpartum depression seek out therapy. So the accessibility to therapy isn't always there, as well.

If you look at real, low-cost interventions that people can do to help prevent postpartum depression, exercise is one of them.

Erica Pearson • 612-673-4726