Exercise and Mental Health
Updated: Apr 9
When mental health is mentioned, most people still think of two things: medication and therapy. However, modern science clearly shows that mental well-being is directly related not only to thoughts but also to the body, hormones, nervous system, and daily habits . Today, depression and anxiety are among the most common health problems worldwide. Despite this, a large proportion of these problems either never receive treatment or are managed only with solutions that suppress symptoms. It is precisely at this point that a tool we have known for a long time but have not taken seriously enough comes to the forefront: physical activity .
For many people, exercise is still synonymous with getting fit, losing weight, or looking better. However, scientific data shows us that exercise is not just an aesthetic tool; it is a powerful biological and psychological intervention that directly affects the brain.
Regular physical activity rebalances stress systems, alters brain chemistry, stabilizes mood, and improves sleep, focus, and mental resilience. Moreover, it does all this with a much lower risk of side effects compared to medication.
This article will explore how and why exercise affects mental health, not with superficial explanations like "it feels good," but by examining it at the level of the brain, hormones, and nervous system .
THE EFFECT OF EXERCISE ON THE BRAIN AND BIOLOGICAL MECHANISMS
The effect of exercise on mental health is not a "motivational story"; it is the result of measurable biological processes . This effect occurs through three main systems.
1) BRAIN CHEMISTRY: ENDORPHINS AND ENDOCANNABINODIDES
During physical activity, the brain increases certain neurochemicals that are normally released only under specific circumstances:
Endorphins (especially β-endorphins)
- They are natural pain relievers.
- It creates a feeling of relaxation and well-being.
- It works in the opposite direction to a depressed mood.
Endocannabinoids
- It reduces anxiety.
- It provides calmness and mental relaxation.
- It is an important part of the "feeling good after exercise" state.
Thanks to these substances, exercise suppresses anxiety, softens emotional fluctuations, and can improve mood even in the short term. This effect is the real biological basis behind "feeling better after exercise."
2) STRESS SYSTEM: HPA AXIS AND CORTISOL
Chronic stress is centered on the HPA axis (hypothalamus–pituitary–adrenal axis). When this system is overactive for a long time, cortisol levels remain consistently high, sleep is disrupted, anxiety increases, and emotional regulation becomes difficult. Regular physical activity, however, retrains this system.
Research shows that exercise:
It ensures more stable operation of the HPA axis.
It lowers basal cortisol levels.
It makes the stress response more controlled.
As a result, individuals react to stressful stimuli later and more mildly, feeling "more resilient" in daily life. This effect is one of the key mechanisms explaining why exercise reduces the risk of anxiety and depression in the long term.
3) BRAIN STRUCTURE: BDNF EFFECT
Perhaps one of the most critical effects of exercise is the increase in BDNF (Brain-Derived Neurotrophic Factor) . BDNF strengthens connections between nerve cells, supports learning and memory, and makes the brain more resistant to stress and degeneration.
Low BDNF levels are associated with depression, cognitive decline, and loss of mental plasticity. Increased BDNF, resulting from regular exercise, supports mental performance and enhances the brain's "adaptive capacity." Therefore, exercise positively impacts not only mood but also focus, learning, and mental clarity .
MOOD, FOCUS, AND SELF-ESTEEM
Explaining the effects of exercise on mental health solely through chemical substances is incomplete. The human mind is nourished not only by brain chemistry, but also by perception, a sense of control, and self-evaluation . This is one of the areas where exercise truly shines.
Most people experience a common change with regular physical activity: a shift in their self-perception. This change is far deeper than simply "looking fitter."
An individual exercising:
He is in more physical contact with his body.
He recognizes his physical limitations.
He gains experience in being able to manage a process.
This, over time, fuels the following idea:
"I can change things."
In psychology, this is defined as a sense of self-efficacy and is a critical factor for mental health. In conditions like depression and anxiety, one of the most damaging things is feeling powerless and out of control . Exercise, even just a few days a week, gives a person a sense of control again.
This is where the effect on mood comes into play. Individuals who exercise have milder emotional responses to daily stressors, and mood swings are less abrupt. Part of this, of course, comes from neurochemical mechanisms; however, a significant part is related to the reconstruction of psychological building blocks .
The issue of focus and mental clarity should be addressed similarly. Many people experience these effects, even if only for a short time, after exercise:
He thinks more clearly.
It's easier to focus.
He feels that his mental clutter has decreased.
This effect is related to exercise increasing brain blood flow, raising BDNF levels, and suppressing stress hormones. However, in practice, it means the mind moves away from constant "alarm mode" and becomes more functional . Therefore, exercise is a tool that makes mental performance more sustainable.
EXERCISE AND DEPRESSION
Depression is one of the most common and debilitating mental disorders worldwide. Despite this, access to depression treatment remains limited, and many people either do not receive treatment or do not benefit sufficiently from the treatment they receive. In this context, exercise has become an increasingly researched area in recent years.
The fundamental question being asked is this:
Does exercise actually reduce depression, or does it only provide a temporary "feel-good" effect?
Review studies and meta-analyses show that exercise has a significant reducing effect on depressive symptoms. In some studies, this effect has been found to be close to that of antidepressant treatment , especially in mild-to-moderate depression. There are several key explanations for this effect.
First, there's the endorphin and endocannabinoid system mentioned earlier. Exercise activates the brain's natural "feel-good" mechanisms. This can make a significant difference, especially in individuals experiencing anhedonia (inability to experience pleasure).
Secondly, there is the suppression of the stress system . Depression is often intertwined with chronic stress. Continuously high cortisol levels further worsen mood. This cycle can be partially broken with regular exercise.
The third, and perhaps least discussed but most important, point is behavioral activation. Individuals with depression often move less, have less social contact, and withdraw from daily routines. Exercise is one of the rare interventions that can pull a person out of passivity. As a person exercises, they are pushed out of the depression cycle not only physiologically but also behaviorally .
However, it is important to remember that exercise is not a miracle cure . Studies show that its effectiveness varies from person to person. For individuals with advanced and severe depression, exercise alone may not be sufficient. The best results are usually seen when added to standard treatment .
Therefore, exercise is not a method that "solves" depression, but it is a component that makes treatment stronger and more sustainable. From this perspective, exercise should be considered not so much an alternative in the treatment of depression, but rather a fundamental supportive building block .
ANXIETY AND SLEEP
Anxiety is often misunderstood. The problem isn't that a person experiences stress; the problem is that the stress system never shuts down . This constant state of alertness tires the mind and body in the long run. This is where exercise plays a simple but effective role: it teaches the body to send "safety" signals again.
In anxiety disorders, the HPA axis and sympathetic nervous system are often overactive. This increases heart rate, heightens muscle tension, and constantly focuses the mind on potential threats. Regular physical activity teaches this system to readjust rather than suppress it. Even though stress hormones temporarily increase during exercise, in the long term the body learns to respond to stress in a more controlled manner. Therefore, in individuals who exercise, the emotional response is milder even if daily stressors remain the same.
Scientific studies suggest that while exercise alone is weaker than medication in treating anxiety, it is significant and consistent as a supportive treatment. This difference is important. Exercise is not an intervention that "zeroes out" anxiety; however, it increases a person's capacity to cope with anxiety. In other words, it prevents the mind from remaining constantly on high alert.
This is where sleep comes into play. There is a bidirectional relationship between anxiety and sleep. Poor sleep increases anxiety, and increased anxiety disrupts sleep. Exercise is one of the rare interventions that can break this vicious cycle.
Research shows that regular exercise:
that it prolongs sleep duration,
that it improves sleep quality,
It supports REM sleep,
It shows that it reduces very light sleep stages.
Exercise doesn't create a "forced sleep" effect like a sleeping pill. Instead, it strengthens the body's natural sleep rhythm . This is supported by the fact that the effect of exercise on sleep is more pronounced in individuals with mental health issues.
CLINICAL EXAMPLES
The impact of exercise on mental health is not limited to healthy individuals experiencing daily stress. It also shows significant results in clinical populations, particularly as a supportive tool.
Schizophrenia is one of the most striking examples of this. In schizophrenia, positive symptoms (delusions, hallucinations) can often be controlled with medication. However, the real problem is usually the negative symptoms such as loss of motivation, social withdrawal, and emotional blunting.
Research shows that regular physical activity, and especially structured forms of movement like yoga, significantly reduces these negative symptoms. This isn't solely due to physical movement. Exercise promotes routine, increases body-mind awareness, and reduces metabolic side effects. Considering issues like weight gain and metabolic syndrome associated with antipsychotic medications, exercise plays an indirect but critical role.
Another important area is addiction disorders. One of the most challenging problems in alcohol and substance addiction is craving , or intense desire.
Exercise works in two ways here:
It positively affects brain chemistry.
It offers the individual a "way to find relief" outside of the material world.
Studies show that regular physical activity reduces alcohol cravings and provides significant support, especially when access to other treatments is limited. However, exercise is not a passive treatment for addiction; it requires the individual's active participation. Therefore, its effect is much stronger when used in conjunction with motivational approaches.
All these examples show that exercise is not a method that "cures" severe psychiatric illnesses. However, in many cases , it is a strategic supportive tool that reduces the burden of symptoms, alleviates the side effects of treatment, and significantly improves quality of life.
HOW MUCH EXERCISE IS ENOUGH?
When it comes to exercise, the most frequently asked question is:
"How much do I need to do?"
Scientific guidelines argue that approximately 150 minutes of moderate-to-high-intensity physical activity per week is effective . This recommendation is associated with significant benefits in many areas, including mental health. However, it's not just about reaching that number.
There is an even more important fact that the research has shown:
Going from doing nothing to doing even a little bit makes the biggest difference.
In other words, the difference between following a perfect five-day-a-week schedule for mental health and engaging in short but regular daily activities isn't as significant as one might think. The key is consistency.
While the effects of exercise on mental health show a dose-response relationship, this relationship is not linear. Initially, small increases yield great benefits; however, gains slow down at higher levels. Therefore, the "more is better" approach is both scientifically incorrect and unsustainable.
Another important point is not so much the type of exercise itself, but rather the individual's relationship with it . Exercise of the same duration and intensity may be relaxing for one person and stress-inducing for another. When it comes to mental health, the perceived strain of exercise is just as important as its physiological effects. Challenging but manageable effort strengthens the mind; excessive and unsustainable effort, on the contrary, can become a source of stress.
Therefore, the scientific approach suggests starting with low or moderate intensity, finding your personal rhythm, and aiming for consistency rather than performance.
CONCLUSION
All the data we've discussed in this article converges on a single point:
Mind and body cannot be treated as separate systems in practice.
Exercise:
It alters brain chemistry.
It reorganizes stress systems.
It stabilizes mood.
Sleep improves focus and mental resilience.
But perhaps more importantly, it restores a functional structure to the individual. Feeling capable of doing, maintaining, and controlling things in daily life is one of the most fundamental building blocks of mental health.
Exercise alone won't solve mental health problems. However, when applied correctly, it can make almost any treatment more powerful, more lasting, and more sustainable .
And perhaps the most crucial point: You don't need to be an elite athlete, have perfect training programs, or be extremely disciplined to achieve this effect. What's needed is to make the body an ally of the mind once again.
Reference:
Mahindru A, Patil P, Agrawal V. Role of Physical Activity on Mental Health and Well-Being: A Review. Cureus 2023 Jan 7;15(1):e33475. doi: 10.7759/cureus.33475. PMID: 36756008; PMCID: PMC9902068.
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