Mental health issues affect one in five every year. The Canadian Mental Health Association estimates that by the age of 40, about half of people will either have had a mental illness or currently have a mental illness.
Behavioral therapy and medication are the first common treatment options. However, research has shown the importance of exercise not only for preventing mental illness, but also for treating it. And when the exercise is done outdoors, the benefits can be even greater.
Mental illnesses include depression, addictions and anxiety, as well as personality disorders. Of these, anxiety and depression are the most common, depression being the number one cause of disability worldwide. If left untreated, these illnesses can lead to physical illness and premature death.
My research focuses on the benefits of physical activity to prevent and manage disease, and ways to facilitate physical activity. In December 2021, I was diagnosed with major depressive disorder, and exercising and spending time in nature were essential to my recovery.
Exercise can make you happy

Exercise and activity have long been known to improve mood. A study of more than 1.2 million adults in the United States found that those who exercised had 1.5 fewer days in the last month of poor mental health. And the greatest benefits occurred in people who exercised 45 minutes or more for three or more days a week.
But even shorter sessions can make a difference. As little as ten minutes of activity was enough to improve happiness. Over time, regular exercise can lead to less risk of depression And anxiety. It doesn’t matter what kind of activity you do. Whether it’s team sports, cycling, walking, running or aerobics, they all offer benefits. Even active household chores can reduce the risk of depression.
Exercise as a treatment for mental illness
Many studies indicate that exercise is an effective treatment for people with depression and other mental illnesses. A meta-analysis found as little as four weeks of exercise reduced symptoms of depression in people with major depressive disorder. That’s less time than it takes for most antidepressant medications to work.

Although exercise is beneficial at all levels of intensity, it seems higher intensity exercise may be more effective than lower intensity. Strength training can also reduce symptoms in people with depression. And a recent review of studies with 128,119 participants reported exercise is as effective as antidepressants for the treatment of non-severe depression. Exercise has also been shown to reduce symptoms in people with clinical anxiety And schizophrenia.
How exercise improves mental well-being
Exercise can improve mental well-being due to hormone release and brain function. The exercise results in the release of endorphins And endocannabinoids. Endorphins are feel-good hormones that reduce pain or discomfort associated with activity. Endocannabinoids act on the same system affected by marijuana, reducing pain and improving mood.
In the brain, low levels of brain-derived neurotrophic factor (BDNF) and one small seahorse have been linked to a number of mental illnesses. BDNF is important for the growth of nerves in the brain and the development of new neural connections, while the hippocampus is associated with learning, memory, and mood. The exercise can increase BDNF levels in people with depressionas well as increase the volume of the hippocampus.
Take it outside
Exercising in nature can further improve mental well-being. Rumination is a negative pattern of repetitive thinking and apprehension. It is associated with greater risks of mental illness, but can be reduced with a walk in a natural environment. And people who spent at least two hours in nature in a week said superior well-being compared to those who had no contact with nature.

There are many reasons why nature is good for us. Trees are known to release compounds called phytoncides, which have been linked to multiple health benefits. Besides, cortisol (the stress hormone) levels are reduced with as little as 20 minutes spent in a park.
The value of being outdoors for physical and mental health was recognized by Parks Canada in January 2022, when they in partnership with PaRxan organization run by medical professionals who prescribe time in nature to their patients, to enable doctors to prescribe Parks Canada discovery passes for adults.
Through these passes, patients can access Canada’s National Parks, National Historic Sites and National Marine Conservation Areas. This follows similar programs in many other countries such as New Zealand, Japan, the United States and the United Kingdom.
With all the mental health benefits of exercise and nature, it’s important to recognize that some people with mental illness may find simple daily tasks challenging. For these people, taking an antidepressant and behavioral therapy may be more appropriate. But for others, exercising in nature is a simple and economical activity to maintain your mental health and treat mental illnesses.
Scott Lear writes a bi-weekly blog Become your healthiest you and co-hosts a monthly podcast How the health.