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The Dose Transcript for January 2, 2025

Host: Dr. Brian Goldman

BRIAN GOLDMAN: Hi, I'm Dr. Brian Goldman. Welcome to The Dose. Well, it's January, the month of cold weather and dark mornings. It's peak season for seasonal affective disorder or SAD, you know, a kind of depression that appears at certain times of the year. And it's especially hard for the millions of Canadians with depression. Now, I have been a runner for decades, as I've talked about on The Dose. And it is my go-to for beating the blues. Turns out science is showing us just how effective physical activity is as a way to treat depression and the winter blues. So this week we are asking: What is the best exercise for depression? Hi, Catherine. Welcome to The Dose.

CATHERINE SABISTON: Hi, thanks for having me.

BRIAN GOLDMAN: So what exercise do you do specifically when you're feeling down?

CATHERINE SABISTON: I am also a runner. So, I go outside and I run with my dog and we enjoy the nature and the outdoors.

BRIAN GOLDMAN: How important is it for you to be running with your dog?

CATHERINE SABISTON: Extremely important for me. I mean, I think it depends on everyone's preferences. But for me, I love having an animal with me. It makes me feel safe. It makes me feel happy. I love watching her. She runs with a ball in her mouth. So, the number of people that look around and smile, she brings joy to other people because she's pretty goofy herself while we run. So I just love that environment.

BRIAN GOLDMAN: We have the task at hand, which is to answer the question that we've asked on The Dose. But before we do that, can you give us a hi, my name is? Tell us what you do and where you do it.

CATHERINE SABISTON: Hi, my name is Catherine Sabiston, and I'm a professor at the University of Toronto in the Faculty of Kinesiology and Physical Education. I also hold a Canada Research Chair in physical activity and psychosocial well-being.

BRIAN GOLDMAN: Which is why we came to you for this episode of The Dose. What does the latest research tell us about how physical activity can help with depression?

CATHERINE SABISTON: Exercise is helpful for symptoms of depression. It helps with prevention of depression and poor mood. It helps for people who are managing the symptoms of depression. It helps in that management. And then it also helps with treatment. So we see a lot of research now also adding exercise to other forms of treatment for depression. Quite uncontested evidence to say that there's a good relationship there.

BRIAN GOLDMAN: Can we say that if it's true for depression that exercise helps, that it would also help for the winter blues and seasonal affective disorder?

CATHERINE SABISTON: Absolutely. I mean, seasonal affective disorder is sort of a sub-dimension of depression that happens at certain times of year, specifically in winter months because of, you know, how short the days are and the darkness and the cold. Obviously for us in Canada, we experience it more than in other parts of the world. And so having something like exercise to help relieve some of the symptomology of seasonal affective disorder has been proven in research as well.

BRIAN GOLDMAN: So what happens in the brain while you exercise?

CATHERINE SABISTON: Many, many little things. So, the research shows that exercise has an impact on neurotransmitters in the brain. It increases blood flow throughout the body and the brain. It helps with serotonin and dopamine, which are sort of known precursors to depression and anxiety. So, there's a number of sort of mechanisms, I would say, that happen in the brain when you exercise. And that's just one of many of the reasons or the ways in which we see the benefits of exercise on depression, is that sort of brain mechanism piece of it. But certainly lots of action in the brain that helps with mood and with depression.

BRIAN GOLDMAN: Are there any particular structures in the brain, parts of the brain, that seem to be increasingly important?

CATHERINE SABISTON: In general, the norepinephrine, the endorphin releases of the brain. The hippocampal growth that happens around something called brain-derived neurotrophic factor, or BDNF is what we commonly see it as, which is a protein that supports the growth of neurons in the brain. So we see that over time, while this isn't like an acute action of exercise on the brain, over time, there's this building of BDNF, certainly showing that, you know, the brain is not atrophying or shrinking because of something like depression. We also see another sort of... fancy term, but the hippocampus-pituitary-adrenal or the HPA axis is another sort of mechanism that exercise affects. And with the HPA axis, we see that this is tied to these excess cortisol levels. So if people follow, you know, sort of stress and anxiety, cortisol plays a big role in our immune function and our stress levels, which is linked to higher levels of depression. So, many, many different kinds of mechanisms that we're really only truly starting to understand now with technology advances and the ability to, you know, actually do scans of the brain and explore sort of some of these mechanisms that are happening around exercise specifically.

BRIAN GOLDMAN: What does the research tell us about how exercise stacks up against other treatments, you know, fairly standard treatments for depression, like antidepressants and cognitive behavioral therapy or CBT?

CATHERINE SABISTON: Yeah, so what we see is a mix of research always showing that exercise does no harm. And so what we see is when we plot exercise against something like antidepressants, we do see that exercise has benefits that are quite similar actually to the antidepressant effects. And we also importantly also see that exercise doesn't have the same side effects as antidepressants. And so, oftentimes, if people are willing to sort of give it a try, it gives the same benefit as well as does not have, you know, sort of some of the more negative side effects tied with pharmacological interventions. And then, you know, when we stack it up to things like CBT or other types of mindfulness-based therapies, we see that exercise is as good if not better than some of those treatments as well. And then we also know that exercise is better than doing nothing at all. And so, all in, exercise is at least as good as any of the other treatments that we see being used for depression.

BRIAN GOLDMAN: Catherine, you've been a great sport because I've taken you far outside your comfort zone. You're not a medical doctor. I'm now going to take you back right into your area of expertise. What kinds of exercise are the best for addressing depression, the symptoms of depression?

CATHERINE SABISTON: I won't tell you that one exercise is the best for depression, because ultimately, it sounds pretty cliché, and I'm sure we've heard it again and again, but, the best exercise is the one that people will do. And so ultimately, a good outcome of the exercise and depression research is that we used to focus on, you know, high intensity, certain types of exercise that was beneficial for mental health. And now what we see is that over time, research has started to move into areas of other types of exercise. And so now we see that you don't have to have the high intensity exercise in order to see the benefits on mental health. You can engage in lower intensity types of exercise that are equally as helpful for, especially for mental health. And we see this not only in, you know, sort of healthy populations, but also individuals dealing with other chronic disease as well. And some of the lighter forms of exercise are, again, the types of exercise that people feel that they can engage in, that are more conducive to their lifestyles. And the benefit is that we do see that there is a link between those types of exercise and depression symptoms as well. So it's encouraging from my perspective because we used to force people to do exercise that they really don't enjoy doing -- the higher intensity exercise at a certain time and a certain bout. And now we can sort of relieve some of those criteria and really focus on what people enjoy. And you can see how that makes sense. You know, if you're doing something that you enjoy, you're putting that together with moving your body, increasing the blood flow again, the brain mechanisms as well as a number of other reasons why this works. And then in turn, that helps with the symptoms of depression.

BRIAN GOLDMAN: And so, you know, if we're talking cardio resistance, you know, weight training, indoor/outdoor, you find what works for you. Have I got it right?

CATHERINE SABISTON: Absolutely. And we also know that a layering effect exists in individuals. You know, you mentioned running. I also run. And the outdoors is so important for people. And it's one of the -- again, if we cycle it back to seasonal affect disorder, you know, the outdoors are, it's cold, it's gross, it's, you know, you're not dressed appropriately, you're not enjoying it. But if you can get outside and move, going outside for a walk is so important for people in general to put together being outside plus the movement. And we know that that has such a good effect for people with depression symptoms in particular.

BRIAN GOLDMAN: So, for example, if somebody has seasonal affective disorder, part of that prescription for exercise might be to get them out exercising when there's sunlight so that they can top up their exposure to sunlight, which is so lacking and so important in the pathogenesis of seasonal affective disorder.

CATHERINE SABISTON: Absolutely. And the outdoors, the natural light, regardless of whether there's sun, I mean, ha, we can't always guarantee that there's going to be sun, but we can guarantee that there's going to be some hours of the day when it's light enough out where, again, you feel safe and comfortable, and you're outside in the fresh air enjoying that time. And it's about looking at being intentional about going outside, and planning that so that, again, there's a feeling of mastery: you've planned it. You go outside, you're doing what you have set yourself to do. It's a goal. There's many sort of psychosocial factors that come into play, even with a structured plan to do some exercise outside. And so, yes, the fresh air. Obviously if there's sunlight, even better. But the natural light and moving while being outside are so critical for symptoms of depression.

BRIAN GOLDMAN: How long do you have to exercise to feel the benefits in improving mood and reducing depressive symptoms?

CATHERINE SABISTON: We used to say that there is a certain amount of time, and for those who follow, you know, Canada Physical Activity Guidelines, the idea of moving for at least 30 minutes a day is still very real for a number of health benefits, at least five days a week and at a moderate intensity. But there's benefits to shorter periods of movement for depression specifically and for anxiety. So if we loop together both depression and anxiety, we can see that there's benefits with really short bouts of movement. So even if it's a couple of minutes or five minutes here or there throughout the day sprinkled in, the key is really to make sure that that movement is intentional. So again, you've planned it and you're making an intentional decision to move more throughout, you know, where you live, where you work, in your community. And by moving more, even in those like really short few minutes here and there, it builds it up throughout the day. And some would say that multiple smaller bouts of movement are even more important for people with symptoms of depression, including seasonal affective disorder, because it helps you move a little bit more throughout the day rather than, you know, sort of one bout that may last for a little bit, but might not give you the lingering effects that you might be looking for in symptoms of depression.

BRIAN GOLDMAN: If you were coaching somebody who was just starting out with an exercise program to try to address their mood, what would be a good place to start with them? What would be the bare minimum? How would you begin coaching them?

CATHERINE SABISTON: It's really about, first of all, that you're doing something that you at least think that you're going to enjoy. I mean, experimenting with a whole bunch of different exercises and movements is really important for people in general. There's a lot of different ways that you can find exercise information and videos online, on apps. There's-- in your own communities, there's gyms, there's spaces. If you want to do your own thing, just moving more, walking. Integrating exercise throughout. You know, I, I joke that I say, you know, even if you're making yourself breakfast and you put the toast in the toaster, you know, there's some exercises you can do while the toast is toasting. So it has to be intentional, again. But making sure that you have a plan that you have thought through what that looks like, that it's doing movement that you know that you'll enjoy. And I also find it really helpful for people when they're starting out to keep track. We think of keeping track and log books and diaries of how you move over time. Writing things down works. And so now, you know, the writing it down doesn't necessarily have to be in that traditional way. It can be using a tracker of some sort or taking notes on your phone or on your device or whatever. Whatever you have around you. Or the piece of paper. But keeping track makes you feel that you're contributing to your own sense of self and well-being. It helps you see what you've done. It also helps you see how you can incorporate a few more steps into your day, even if you don't end up leaving the house or where you live. So I think that's the other important thing, is to keep track, to be intentional, to set those goals that are achievable and something that's important to you to do. And that's how you get started.

BRIAN GOLDMAN: Any idea how long the benefits of individual exercise last? I know that most of the guidelines for fitness suggest that you should be doing something every day or most days of the week.

CATHERINE SABISTON: It's about what you're doing and how intense you're working out and how much your body needs to recover. So there's a number of different factors that come into play around how long, you know, these effects last. In the end, it's about focusing on what you're doing for you and making sure that there's a plan, that it's intentional in your day, and that you're focusing on it. And all of those things combined will help, at least throughout the day, if not every day. So if you are incorporating movement every day at that lighter intensity, multiple bouts per day, you want to try to do that every day, because there's also something about having it be a habit or some sort of regular schedule that is also very important for people's general health. And so being able to do some form of movement throughout the day, at a relatively regular schedule or at least every day, is important for, especially for depression and anxiety. You would say that maybe there's other health benefits to movement -- which we could be here all day to talk about -- that might need different levels of exercise and at different intensities. But when we're talking specifically about mental health, the benefits of just incorporating more and more throughout your day and being intentional about it and trying to do that on a daily schedule has so many benefits.

BRIAN GOLDMAN: How important is it to connect with your health-care provider when you're embarking on an exercise program? I'm thinking there are people who are listening to this who might be older, they might have other medical conditions. And I'm also aware that there are people these days who are looking for a prescription for exercise from their doctor.

CATHERINE SABISTON: It is important to speak to a health-care professional when you are going to start an exercise program. It's important to know that, you know, you're just in a place where whatever you're planning on doing is going to be helpful to you and that your body is in a place where it's ready. I would say that starting with a slow, progressive, moving-more kind of model is something that you could do without the care of a health professional. But if you are going to move beyond that and start engaging in a more intense, I would say, exercise program, very important to have a health-care professional to meet with them. There's certainly screening tools that we use to make sure that people are in a place where they can exercise the way that they want to. Again, because we know that the best type of exercise is what you're going to want to do. And so you want to make sure that you're able to do that. And I would say in Canada, we haven't advanced as far as other parts of the world in terms of exercise prescription, but it's certainly something that's talked about quite often in certain clinical populations, like individuals with diabetes or with cancer. There is advances in terms of prescription for exercise. When we hear from our physician or our primary care individuals that exercise is helpful, it's more likely to resonate with people. They are more likely to engage in exercise if the physician has told them so. So it's about communication. It's about having that prescription. I mean, the prescriptions in general are really: Move more. Or: Here's your prescription to engage in exercise. There's also many other social prescriptions that people can engage with. So if exercise at higher intensities is not something that someone can do, there's other social prescriptions for music and art and other forms of social connection and integrating oneself into the community to help with depression and anxiety specifically.

BRIAN GOLDMAN: Final question I want to ask you. It occurs to me that some people listening to this program, maybe persons with disabilities, they want to exercise too. Where can they go to get information and advice on how to set up an exercise program?

CATHERINE SABISTON: We really try to think about the types of considerations that we make around individuals with physical disabilities, intellectual disabilities. And, you know, there's more and more focus on trying to make sure that exercise, that the research is there to show that exercise is beneficial. And so it's about making sure, again, speaking to health-care professionals, engaging in the communities in which one lives around making sure that there's a place to exercise safely. With these, I would say, new messaging around exercise where it is about moving more, it's not necessarily that you need to have a prescription and a program to follow. But it's certainly many community centres, many areas in the places that you live around Canada, have now had big focus on making sure that there's accessible movement spaces in the community. And so it's about looking for those abilities to exercise in communities where they've put the efforts in.

BRIAN GOLDMAN: So the bottom line here, Catherine Sabiston, is get up and move. It's good for your body and it's good for your emotional well-being as well.

CATHERINE SABISTON: It's about not only taking that first step, but that first wheel, that first roll, that first -- you know, so that it's not about just those who can actually take a step, and making sure that that language is there as well.

BRIAN GOLDMAN: Professor Catherine Sabiston, thank you so much for speaking with us on The Dose.

CATHERINE SABISTON: Thanks for having me.

BRIAN GOLDMAN: Catherine Sabiston is a professor in the Faculty of Kinesiology and Physical Education at the University of Toronto, and Canada Research Chair in physical activity and mental health. Here's your dose of smart advice. Depression and anxiety are common mental health disorders. The winter blues are a wave of low emotions that come during winter's cold and dark days. Seasonal affective disorder, or SAD, is a form of depression that occurs during the winter. Regular exercise helps the winter blues, SAD, major depressive disorder, and anxiety. Exercise works on the amygdala and the hippocampus in the brain. Exercise releases endorphins, which improves well-being and helps dampen the stress response. Physical activity also distracts you from negative thoughts associated with depression. It can help you gain confidence by meeting exercise goals and improving self-esteem. If you exercise in a group or with a buddy, it increases motivation and social interactions. A 2023 analysis of research found that supervised group or individual exercise decreases symptoms of depression as effectively as psychotherapy and medication. Thus far, though, research has not found that exercise works better than antidepressant medication. Moderate to vigorous intensity aerobic or resistance exercise for 45 to 60 minutes, 3 to 5 times per week, has been shown to act like an antidepressant, though the latter may also be recommended by your health-care provider. See your health-care provider to make certain you don't have medical conditions that might restrict how much exercise you can attempt. Your health-care provider can prescribe the frequency, intensity, time and type of exercise that's best for you. The most important thing is that exercise works best when you make a personal commitment to do it. You choose the program. Start low and build up. And remember, if you aren't able to reach your goals for exercise, know that any physical activity is better than none. If you have topics you'd like discussed or questions answered, our email address is thedose@cbc.ca. If you liked this episode, please give us a rating and review wherever you get your podcasts. This edition of The Dose was produced by Prapti Bamaniya and Sameer Chhabra. Our senior producer is Colleen Ross. The Dose wants you to be better informed about your health. If you're looking for medical advice, see your health-care provider. I'm Dr. Brian Goldman. Until your next dose.

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What's the best exercise for depression? - Transcript

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