One in five Canadians is living with mental health challenges such as anxiety and depression at any one time.
This number has climbed steadily in recent years, and while we have improved how we talk about mental health, significant stigma remains. In fact, people are almost three times less likely to report a mental illness than a physical one.
There are many effective mental health treatments available. However, access to diagnosis and treatment can take years. Sometimes prescriptions used to treat mood disorders have side-effects that can cause people to avoid or stop taking their medication. Traditional therapy can be costly and is not always covered by insurance or benefits.
Meanwhile, there is another tool — regularly prescribed for improving heart health and metabolic health — that can be an incredibly useful addition to mental health care and management. What tool could possibly treat so many conditions? Exercise!
Yes! Lifting weights does lift your mood
Many people have experienced the feeling of post-workout bliss, but
can hitting the gym actually help with depression and anxiety? The science says — absolutely!
Exercise has been proven to actually improve symptoms of anxiety and depression in both the short and long term. It can help with mood regulation, and in particular, emotional resilience to acute stress. While reports on improved mood following a workout can seem subjective, the benefits of exercise on mental health can actually be observed at the biochemical level.
You may have heard the term “runner’s high,” which stems from the feeling of bliss or euphoria many people experience following exercise. This is largely caused by an increase in what we call endocannabinoids and endorphins — hormones and molecules that make you feel happy or content.
‘Good’ and ‘bad’ tryptophan metabolites
There may also be another important molecule to thank, though — tryptophan.
Tryptophan is an essential amino acid that we absorb through our diet, and it plays many important roles within the human body. Tryptophan makes serotonin — often called the feel-good hormone — but it can also be broken down to produce molecules that have differing effects on the brain and body.

Many different forms of exercise can boost your tryptophan metaboiities and boost your mood.
(Getty/Unsplash+)
The main pathway responsible for breaking down tryptophan is called the kynurenine pathway. Some of the products from this pathway, like kynurenic acid, can be protective against inflammation, and good for brain health. Others, like quinolinic acid, can be associated with toxicity and inflammation.
In fact, many chronic conditions such as depression, Alzheimer’s disease and cancer have been associated with increased levels of “bad” kynurenine metabolites.
Given tryptophan’s association with both mental health and neurodegenerative conditions, researchers have started to investigate how we can generate more of the good molecules, and less of the bad. By influencing which route is taken in the kynurenine pathway, we may be able to switch towards a healthier, neuro-protective state.
Exercise seems to be a strong regulator of this switch.
An immediate return on investment
Studies have shown that working out can cause immediate and direct increases in brain-protective molecules like kynurenic acid, which have been measured within the blood and muscle following exercise. These beneficial changes have been found following endurance cycling, weight lifting and HIIT training.
Populations with additional metabolic conditions, like Type 2 diabetes, have also seen beneficial changes to tryptophan metabolites following a single exercise session.
Better yet, these improvements have been reported across different age groups, suggesting benefits for both younger and older populations.
So far, laboratory-based studies have largely used traditional exercise protocols like cycling and resistance training. However, being more physically active in general appears to improve your profile of these metabolites, meaning you don’t necessarily need to workout in a lab to see improvements.
While exercise shows a lot of promise as a source of mood enhancement and brain protection, research in this field is still growing. More work is required to understand the exact mechanisms at the molecular level that explain how and why exercise plays such an important role in regulating these metabolites.
Don’t sweat the small stuff; get sweaty!
Ultimately, exercise is a potent tool for contributing to improved mental health. There is strong evidence to support the use of exercise for stress management and production of extra feel-good hormones and metabolites which can aid in the management of mood disorders.
Exercise can also offer an important change of scenery, social outing or simply a dedicated distraction for a short period of time. These factors can be important for mental health. Group activities, like run clubs and pickle ball leagues, could serve as multipurpose mood enhancers.
So, while working out may feel like the very last thing you want to do, especially in the midst of a Canadian winter, the benefits are absolutely worth braving the cold for.
As with any factor of health, there is no “cure-all” approach. Exercise can be a powerful tool for the brain but may not be sufficient to manage complex mental health conditions. Decisions regarding treatment should always be made in consultation with a primary care provider. If you or someone you know needs mental health assistance please see the following resources.