What would you recommend people do instead?
JH: Try to do exercise that feels comfortable and challenging, so that your heart rate looks elevated but not accelerated. For many people, that would mean taking a brisk walk around the park or around the block.
Does exercise help in the same way once morest depression?
JH: Traditionally, depression has been attributed to a lack of serotonin in the brain, which is treated with antidepressants. However, for some people with depression, medications don’t work well, probably because serotonin isn’t their problem. Many of us who study depression now think that the problem may be related to inflammation, which is related to stress. Inflammation begins to damage cells in the body, which induces an immune response and increases inflammation, which can then travel to the brain and affect mood. For those people, exercise can be the medicine they need, because it helps fight inflammation. In studies, when people who haven’t responded to antidepressants start exercising, they usually they see significant reductions in their symptoms.
How much exercise are we talking regarding?
JH: A study looking at the frequency, or the amount of exercise needed to combat depression, compared 150 minutes of moderate to vigorous exercise a week, the standard exercise recommendation for physical health, to a quarter of that. And both groups benefited equally. Therefore, it seems that the exercise prescription for mental health is lower than for physical health, which is good.
In terms of potentially helping to combat depression, do you think the intensity of the exercise is important?
JH: Maybe yes. A few years ago we conducted a study with healthy students facing high-pressure final exams. Some of them moderately rode stationary bikes three times a week for 30 minutes, and others did shorter, more intense interval cycles. A third group did no exercise at all. After six weeks, the students who hadn’t exercised showed symptoms of fairly severe depression, which had come on surprisingly quickly, and presumably because of their academic stress. However, the students who had exercised moderately were less stressed than at the start of the study and had lower levels of inflammation. But what I find really interesting is that those who did intense exercise showed symptoms of increased stress, both physical and mental. So it seems that moderate exercise may be the most beneficial for mental health.
You speak honestly in your book regarding your episodes of anxiety, stress, and obsessive-compulsive disorder, even following the birth of your daughter and, later, your divorce. Did exercise help you cope?
JH: It’s the key. Mental illnesses can happen to anyone, even people who seem to be handling things well. For me and many others, life transitions like divorce and childbirth can be especially challenging. After my divorce, I really needed something to redirect my life. And he knew how powerful exercise is, as a stimulus, to alter the brain. Someone mentioned triathlons. He was still riding a bike at the time. So, I added activities like running and swimming.
