Even just a few hours of exercise a week can help depression. Exercise improves mood and protects against future bouts of depression.

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You’ve probably heard about the benefits of exercise on mental health. But is this backed up by real research? As it turns out, there’s scientific evidence that regular physical activity has health benefits for the mind as well as the body.

So how is it that exercise helps depression?

A physical activity you enjoy doesn’t just make you feel good — it counters many of the biological factors that cause depression.

There’s extensive research to show that exercise helps reduce symptoms of depression in people already experiencing them. Physical activity can also be a protective measure against future episodes of depression.

Researchers are still learning about the biological reasons why exercise has such a positive effect on so many people. It can offer similar benefits to traditional therapy and may even work better than some conventional treatments.


In a 2018 study, exercise was found to be as effective as internet-based cognitive therapy in treating depression. Both exercise and internet-based cognitive therapy had a greater impact on depression than the clinical standard of depression treatment (treatment as usual).

Exercise might also help increase factors that prevent depression or lessen its severity.

Ongoing research has shown exercise improves self-esteem and decreases rumination, both factors that may help reduce depressive episodes.

Research on exercise and depression typically follows people for a few weeks.

But there is also evidence that just one session of exercise improves mood right away. The positive effects can last up to 1 day after stopping exercise.

It doesn’t take much exercise to have positive results.

An 11-year study published in 2017 involving 33,908 people concluded up to 12% of depression cases among the participants could have been prevented, with just 1 hour of exercise every week.

Although exercise can be a critical tool to counter depression, some people get more benefits than others.

Researchers are trying to figure out why by looking at how exercise might affect the body and the brain.

There are known biological factors that increase the likelihood of depression. But exercise can parry these factors, facilitating changes in the body and brain that help alleviate some depression symptoms.

Brain messengers (neurotransmitters)

Dopamine, norepinephrine, and serotonin are three neurotransmitters that help communicate mood. Depression can activate when too few of these chemical messengers are present.

When we exercise, the brain releases more dopamine, endorphins (“feel-good” messenger), and serotonin.

Brain neuroplasticity

Neuroplasticity is the brain’s ability to change. The brains of people with depression often have physical features that, incidentally, exercise has been shown to improve.

The volume of some brain regions, like the hippocampus and prefrontal cortex, is often smaller in people who have depression. The levels of brain-derived neurotropic factor (BDNF), a molecule important for learning, memory, and neuroplasticity, are also lower.

Exercise increases the volume of the hippocampus and other brain regions. Intense exercise also increases the amount of BDNF in the body, perhaps showing exercise can work directly on some biological factors for depression.

Inflammatory brain chemicals

People with depression often have higher levels of specific chemicals connected to inflammation in the body, such as:

Research from 2019 shows exercise decreases levels of IL-6 and CRP, as well as other markers of inflammation.

A 2017 study found that a 12-week exercise program caused changes in IL-6 levels and was associated with a reduction in symptoms in those with mild to moderate depression.


Oxidative stress is when there’s a buildup of byproducts, specifically reactive oxygen and reactive nitrogen, created by the body’s internal processes. Antioxidants remove these waste products, but sometimes there aren’t enough antioxidants to clean up the excess.

The brain is especially vulnerable to oxidative stress because it uses high levels of oxygen and has fewer antioxidant defenses than other parts of the body. Oxidative stress is also a potential contributor to depression.

Exercise causes short-term increases in oxidative stress, but over time, protects against it. More exercise means more antioxidants, which could lead to a reduction of depression symptoms.


A 2019 review found that elevated levels of the stress hormone cortisol were associated with acute and severe major depressive disorder. The same study did not, however, find a connection between cortisol levels and the effectiveness of treatment for depression.

But exercise, although it causes cortisol levels to rise in the short term, keeps cortisol levels stable over the long term. This may prevent long-term damage from high cortisol levels that contribute to depression symptoms.

Depression is a treatable condition. Many people benefit from traditional forms of therapy. There’s also significant evidence that exercise can make existing symptoms of depression less severe and protect against the severity of future depressive episodes.

Exercise changes areas of the brain also linked to depression. Working out mildly to moderately also reduces inflammation, decreases the release of stress hormones, and promotes antioxidant effects in the body. All of which can help people living with depression.

It doesn’t take much exercise to feel the benefits. Although it may take a few weeks before your body’s chemistry begins to change, often people experience an easing of depression symptoms with even just a few leisure exercise sessions a week.

If you’re experiencing depression, you can find help through Psych Central’s onestop therapy hub.