• It's known that exercise boosts mental health, but why is this the case?

  • Therapist and qualified fitness instructor Andrew Keefe explains the impact of exercise on the brain and hormones

  • If you are struggling with mental health despite a healthy lifestyle, you can find a therapist here

There is growing recognition that regular exercise improves your mental health as well as your physical health and fitness. The physical health benefits include a reduced risk of heart disease, some forms of cancer, diabetes, osteoporosis, weight loss and improvements in muscle-tone, flexibility and coordination. Exercise has also been shown to relieve symptoms of depression, anxiety and trauma, and is now prescribed by the NHS for people living with mental health issues.

The NHS advise that 30 minutes of “moderate physical activity” at least three times a week is generally sufficient to have a beneficial effect. “Physical activity” covers a wide range of forms of exercise. Dr Jane Baxter, an American clinical psychologist and certified physical trainer (what would be called a personal trainer in the UK), has developed a work-out routine combining free weight, body-weight and core exercises with positive affirmations and thinking, designed to combat depression. British psychotherapist and keen runner, William Pullen, has developed Dynamic Running Therapy (DRT), combining running or walking with mindfulness, an approach shared by Sakyong Mipham, a Tibetan Lama and experienced marathon runner. 

If this all sounds too vigorous, just going for a walk every day would certainly help, especially if you walk quickly enough to raise your pulse for at least some of the time.

All of these approaches have been shown to improve people’s mental wellbeing, so how does it work?

Why exercise boosts mental health

Exercise involves all of the different parts of the body (bones, muscles, heart, lungs, veins and arteries) coordinated by the central nervous system using the endocrine system to communicate with the rest of the body via the release of hormones. Chemicals including endorphins and dopamine are released during exercise and act on pain receptors in the brain, to allow the body to cope with higher volumes of activity. These chemicals also boost your mood, helping you feel happier, with many people experiencing almost euphoric feelings after a challenging work out or run. Physical activity also causes the release of Body Derived Neuro-Trophic Factor (BDNF) which stimulates brain growth and improves the brain’s ability to think and process information, both of which can be impaired if you are depressed.

People report a variety of effects on thinking while exercising: some people find they can think more creatively while exercising, especially if walking, jogging or cycling. Damon Young, an Australian philosopher and weight-lifter, calls this “Transient Hyperfrontality”. During exercise, the brain puts more energy into its motor and sensory activities (telling muscles, heart and lungs to work in a certain way and receiving information about what the body is doing / how it is performing). The thinking part of the brain, the pre-frontal cortex, gets turned down as a result, making it less powerful and more receptive to ideas and perspectives from other, less conscious and prominent areas of the brain. If you’ve ever had an idea about how to solve a problem, or a flash of inspiration while out walking or running, it may be due to this effect.

During particularly vigorous bouts of exercise, people can have the experience of almost not thinking at all, as if the body and brain’s whole focus has gone on continuing to work: people talk of the relief of getting a break from the negative thoughts of depression, the worried thoughts of anxiety or the frightening thoughts of trauma and of feeling mentally refreshed post-workout, as if their brain has had a rest.

On a deeper level, Baxter shows how emotions are stored in the body as well as the brain since some of the molecules which work together to create the experience of emotions are located in the cells of the body. Emotions can become trapped physically and experienced as stiffness, tightness or pain in the shoulders or neck for instance and hence can be released during a workout.

Trauma can also be stored in the body, even more so than the brain: during a traumatic incident such as an assault, the amygdala, the brain’s alarm system or “smoke detector” as Bessels Van Der Kolk, refers to it, triggers the body’s fight or flight mechanism by sending out stress hormones such as adrenaline and cortisol to the heart, lungs and muscles, to get the body physically ready to protect itself. The hormones trigger processes which reach deep into the fibres of individual muscle cells. A traumatic event can be so overwhelming that the brain’s information processing system breaks down and the information gets stuck in the amygdala which is non-verbal and has no sense of time or place: it can’t be talked about and when something happens to remind the brain of the original incident (when it is “triggered”), it thinks it’s happening again, the same stress hormones are sent out and the body remembers the trauma, meaning you can feel all the same physical sensations again. 

This is all because mind and body are really one and the same: It’s impossible to separate them or tell where one ends and the other begins: where distress cannot be put into words, a more physical approach – a work-out or even yoga, which has been shown to be extremely effective in treating trauma, can help to process and release deeply buried emotion and distress. Even emotions, including pain, are actually registered and experienced bio-chemically within the body, not as somehow internal processes within the brain.

There are many ways to exercise to improve mental health, but personally I believe the most effective way is to workout outside in a group by joining a circuit class or bootcamp for instance: you will get a vigorous session, which will raise your heart beat and provide all of the benefits we have looked at, you will be part of a group which will help break down the loneliness and isolation which so often goes with mental ill-health and you will be outside, in a park or other open space, also able to experience the benefits which being closer to nature can bring.

Further reading

How to change the way you think about exercise

How to get active, and stay active

Dear body, a love letter

What's the tension in your body trying to tell you?

The neuroscience of emotions


Baxter, J. 2011. Manage your Depression through Exercise: the Motivation you need to start and Maintain an Exercise Program. Sunrise River Press. North Branch MN.

Mipham, S. 2012. Running with the Mind of Meditation: Lessons for Training Body and Mind. Harmony. New York.

Pullen, W. 2017. Running with Mindfulness: Dynamic Running Therapy (DRT) To Improve Low Mood, Anxiety, Stress and Depression. Plume. New York.

Van Der Kolk, B. 2014. The Body Keeps the Score: Mind and Body in the Transformation of Trauma. Allen Lane. New York.

Young, D. 2014. How to Think about Exercise. Macmillan. London.