Exercise, Neuroplasticity, and Mood: What the Research Tells Us

Exercise is often recommended as one way to support mental health, and there is good reason for that recommendation. Regular physical activity has been associated with benefits for mood, cognition, physical health, sleep, and overall well-being. For individuals experiencing depression, exercise has also been studied as an active treatment rather than simply a general wellness habit.

What is sometimes less clear is why exercise seems to help. You may have heard explanations involving endorphins, serotonin, dopamine, or the idea that exercise “rewires the brain.” There is some science behind several of these ideas, but the full picture is more complicated. One area receiving considerable attention is neuroplasticity, or the brain’s ability to change and adapt in response to experience.

Research suggests that physical activity can influence processes involved in brain plasticity, including neurotrophic factors, blood flow, brain structure, cognition, inflammation, and communication among neural systems. At the same time, researchers have not identified one single mechanism that explains why exercise can improve mood. Understanding that distinction allows us to appreciate the mental health benefits of movement without turning a complex biological process into another overly simple wellness claim.

What Is Neuroplasticity?

Neuroplasticity refers to the brain’s ability to change its structure and function in response to experience, learning, environmental demands, injury, and repeated behavior. The brain is not a fixed system that stops changing once adulthood is reached. Neural connections can strengthen or weaken, patterns of activation can change, and the brain can adapt as we learn new skills and repeatedly engage with our environment.

This does not mean the adult brain can transform without limits or that every experience produces dramatic structural changes. Neuroplasticity occurs on many levels, ranging from changes in communication between individual neurons to broader changes in neural networks. Some forms of plasticity occur relatively quickly, while others develop through repeated experience over longer periods.

Exercise is one experience that appears capable of influencing several of these processes. A 2026 systematic review and meta-analysis of 59 randomized controlled trials involving more than 5,000 participants found a small overall effect of physical exercise on brain volume. The findings suggested that exercise may be particularly relevant to preserving brain volume rather than dramatically increasing it, and changes in brain volume were positively associated with cognitive improvements (Li et al., 2026). This is a more accurate picture than saying exercise simply “grows the brain.”

The Role of BDNF

One of the most frequently discussed links between exercise and neuroplasticity involves brain-derived neurotrophic factor, usually shortened to BDNF. BDNF is a protein involved in neuronal survival, synaptic plasticity, learning, and memory. Because of those functions, researchers have investigated whether exercise-related changes in BDNF could help explain some of the cognitive and emotional benefits associated with physical activity.

There is evidence that exercise can affect circulating BDNF. A meta-analysis of 21 randomized controlled trials involving 809 healthy participants found increases in peripheral BDNF following both acute exercise and longer-term exercise programs (Wang et al., 2022). Research involving people with depression has also produced evidence suggesting exercise may increase circulating BDNF alongside reductions in depressive symptoms. A 2023 systematic review and meta-analysis of randomized trials found increases in BDNF and reductions in depressive symptoms among adults with major depressive disorder who participated in exercise interventions (da Cunha et al., 2023).

However, this area of research is not completely settled. An overview of 11 systematic reviews and meta-analyses found evidence linking BDNF with major depressive disorder and antidepressant treatment, but it did not find consistent evidence that physical activity reliably changed BDNF across the existing meta-analytic literature (Cavaleri et al., 2023). Differences in study populations, exercise programs, blood measurements, timing, medication use, and sample size may contribute to these inconsistent findings.

There is another important limitation: measuring BDNF in the bloodstream is not the same thing as directly measuring neuroplasticity inside the human brain. BDNF remains a promising part of the explanation, but it would be premature to say that exercise improves depression simply because it increases BDNF.

Exercise Appears to Support Brain Health in More Than One Way

Neuroplasticity is unlikely to be driven by one molecule alone. Exercise affects multiple systems at the same time, which may be one reason it is difficult to identify a single mechanism behind its psychological benefits.

Regular physical activity can influence cardiovascular health and cerebral blood flow, which affect the delivery of oxygen and nutrients to the brain. Exercise may also influence inflammatory processes, metabolic health, neurotrophic signaling, stress physiology, and communication within neural networks. Some research has examined changes in neurotransmitter systems as well, including serotonin and dopamine, but these effects are considerably more complex than the familiar idea that exercise simply creates a “chemical boost.”

More broadly, exercise has well-established relationships with cognitive functioning. A 2025 umbrella review synthesized 133 systematic reviews representing 2,724 randomized controlled trials and more than 258,000 participants. The researchers found that exercise was associated with improvements in general cognition, memory, and executive functioning across different ages and populations (Singh et al., 2025).

These findings support the idea that movement can influence brain functioning, but they also reinforce how broad the effects are. Exercise is not acting through a single “happy chemical.” It appears to influence multiple biological and psychological processes that interact with one another.

What Does This Have to Do With Mood?

The evidence that exercise can improve depressive symptoms is considerably stronger than the evidence identifying exactly how it produces those improvements.

One of the largest recent analyses examined 218 randomized trials involving more than 14,000 participants with depression. Compared with active control conditions, walking or jogging, yoga, strength training, mixed aerobic exercise, and tai chi or qigong were associated with reductions in depressive symptoms (Noetel et al., 2024). The authors concluded that exercise could be considered alongside established treatments for depression, although they also noted important limitations in the quality of the underlying trials.

This is an important distinction. We have evidence that exercise can help depression even though we are still working to understand all of the mechanisms responsible for that effect.

Neuroplasticity may be one piece. Changes in BDNF may be another. Exercise may also affect sleep, stress regulation, inflammation, physical health, confidence, behavioral activation, routine, social connection, and the amount of time someone spends engaged in meaningful activity. For some people, exercising outdoors or with another person adds additional benefits that have little to do with what is happening at the molecular level.

The psychological and biological explanations do not compete with one another. They likely overlap.

Exercise Can Interrupt the Low-Mood Cycle

Low mood often changes behavior. When people feel depressed or emotionally depleted, they may withdraw from activities, spend more time alone, move less, and stop doing things that previously gave them enjoyment or a sense of accomplishment. Unfortunately, this reduction in activity can sometimes reinforce the low mood.

This is one reason exercise can be helpful even before considering the neuroscience. Physical activity is a form of behavior that gets someone moving, changes their environment, and creates an opportunity for mastery or engagement. In cognitive behavioral therapy, a related principle is used in behavioral activation, where individuals gradually increase activities that provide meaning, pleasure, connection, or accomplishment.

Exercise can serve some of those functions. Taking a walk may provide movement, sunlight, a change in surroundings, and a break from rumination. Going to a fitness class may add social interaction. Strength training may create a sense of progress or mastery. None of these effects require someone to feel excited about exercising beforehand.

In fact, one of the challenges of depression is that motivation often appears after behavior rather than before it. Waiting until you feel motivated to move can therefore be frustrating. Sometimes beginning with a manageable amount of activity is more realistic than waiting for the desire to exercise to arrive.

The Best Exercise Is Not Necessarily the Hardest One

Research sometimes finds stronger effects with more vigorous exercise, but that does not mean every person experiencing low mood needs an intense exercise program. The effectiveness of any intervention depends partly on whether someone can realistically and safely participate in it.

The 2024 network meta-analysis found benefits across several different types of exercise, including walking or jogging, strength training, yoga, mixed aerobic exercise, and tai chi or qigong (Noetel et al., 2024). This variety is useful because it suggests that supporting mood through movement does not require becoming a runner or joining a gym.

A person who enjoys strength training may choose that. Someone else may prefer walking outside, swimming, dancing, yoga, cycling, or playing a recreational sport. Physical limitations, disability, chronic pain, pregnancy, age, health conditions, access, finances, and personal preference should all shape what movement looks like.

Consistency is difficult to build around an activity you dread. Choosing something reasonably accessible and tolerable is often more useful than selecting the theoretically “perfect” exercise program and abandoning it two weeks later.

Starting Small Still Counts

One of the least helpful messages we can give someone experiencing low mood is that they now have another major thing they should be doing.

Depression can reduce energy, motivation, concentration, and the ability to initiate tasks. Telling someone who is struggling to “just exercise” can make a legitimate treatment option sound dismissive and can create additional guilt when getting started feels difficult.

Movement does not have to begin with an hour-long workout. A ten-minute walk may be appropriate. Stretching for a few minutes may be a starting point. Someone may walk around the block, spend time gardening, take the stairs, or return gradually to an activity they previously enjoyed.

The goal at first may simply be to increase movement from where you currently are rather than measuring yourself against an ideal exercise routine. As energy and confidence improve, the amount or intensity can change.

This approach is particularly important when exercise has become connected to shame, weight, body image, punishment, or rigid expectations. Movement is more likely to support mental health when it is approached as a way of caring for the body rather than correcting it.

Exercise Does Not Need to Become Another Standard You Fail to Meet

There is a strange way that mental health recommendations can turn into another list of things people believe they are doing wrong. Sleep eight hours. Meditate. Eat perfectly. Exercise regularly. Drink enough water. Maintain relationships. Somehow also reduce stress.

That is not particularly helpful when someone is already struggling.

Exercise can be beneficial without becoming a moral obligation. Missing workouts does not mean you are failing at recovery, and experiencing depression despite exercising does not mean you are doing something incorrectly. People respond differently to physical activity just as they respond differently to psychotherapy and medication.

The research also does not suggest that exercise works for every person with depression. Even in studies showing meaningful average effects, individual responses vary. Exercise should therefore be understood as one evidence-supported option rather than a guarantee.

For some people, it may become an important part of treatment. For others, psychotherapy, medication, social support, sleep treatment, changes in life circumstances, or other interventions may play larger roles. Often, several approaches are used together.

Exercise Is Not a Replacement for Needed Mental Health Care

Because the research on exercise and depression is encouraging, it can be tempting to take the argument too far and suggest that people should exercise instead of pursuing other treatment.

The evidence does not support that kind of either-or thinking.

The 2024 review found evidence supporting exercise as a treatment for depression and also found benefits when exercise was combined with established treatments (Noetel et al., 2024). For some people with mild symptoms, increasing physical activity may be one meaningful part of improving well-being. For others, particularly those experiencing significant depression, suicidal thoughts, severe impairment, trauma, bipolar disorder, or other mental health concerns, professional assessment and treatment may be necessary.

Exercise can complement therapy or medication rather than compete with them.

It is also worth acknowledging that depression itself can make exercise difficult. A person who is struggling to get out of bed, shower, eat regularly, or complete basic responsibilities may not currently have the capacity for a structured exercise program. Treatment should meet people where they are rather than using a theoretically helpful behavior as another reason for self-criticism.

What We Know and What We Are Still Learning

The relationship between exercise, the brain, and mood is scientifically compelling, but it is also more complicated than many popular explanations suggest.

We have strong evidence that physical activity benefits physical health and growing evidence that it supports cognition and brain health. We also have substantial randomized-trial evidence showing that exercise can reduce depressive symptoms for many people (Noetel et al., 2024; Singh et al., 2025).

There is also evidence that exercise influences biological processes associated with neuroplasticity, including BDNF, and that physical activity can produce or preserve measurable changes in aspects of brain structure and function (Li et al., 2026; Wang et al., 2022). What researchers cannot yet say with certainty is that one specific neuroplastic mechanism explains the antidepressant effects of exercise. Studies of BDNF in depression, for example, remain somewhat inconsistent (Cavaleri et al., 2023; da Cunha et al., 2023).

That uncertainty does not weaken the case for exercise. It simply means the human brain is more complicated than a single biochemical explanation.

Movement Can Be One Part of Caring for Your Mental Health

Exercise does not need to transform your brain overnight to be worthwhile. Its value may be found in many smaller changes happening at the same time: improved physical health, greater engagement with life, better cognitive functioning, a sense of accomplishment, changes in stress physiology, social connection, and biological processes that support the brain’s ability to adapt.

If you are experiencing low mood, movement can be one tool worth exploring. Start with something realistic, choose an activity that fits your body and circumstances, and pay attention to how you feel over time rather than expecting one workout to change everything.

If low mood is persistent, worsening, or interfering with your ability to function, exercise does not need to carry the responsibility of fixing it on its own. Talking with a mental health professional can help clarify what you are experiencing and whether therapy, medication, lifestyle changes, or a combination of approaches may be appropriate.

The most accurate message from the research is not that exercise is a cure for depression or that it simply “rewires” the brain. It is that movement appears to be one meaningful way we can support a brain that is continually adapting, while also caring for the body and mind as a whole.

References

Cavaleri, D., Moretti, F., Bartoccetti, A., Mauro, S., Crocamo, C., Carrà, G., & Bartoli, F. (2023). The role of BDNF in major depressive disorder, related clinical features, and antidepressant treatment: Insight from meta-analyses. Neuroscience & Biobehavioral Reviews, 149, 105159. https://doi.org/10.1016/j.neubiorev.2023.105159

da Cunha, L. L., Feter, N., Alt, R., & Rombaldi, A. J. (2023). Effects of exercise training on inflammatory, neurotrophic and immunological markers and neurotransmitters in people with depression: A systematic review and meta-analysis. Journal of Affective Disorders, 326, 73–82. https://doi.org/10.1016/j.jad.2023.01.086

Li, G., Liu, C., & Chen, A. (2026). Dose-response effects and mechanistic pathways linking physical exercise to brain volume and cognition: A systematic review and meta-analysis of randomized controlled trials. European Review of Aging and Physical Activity, 23(1), 6. https://doi.org/10.1186/s11556-025-00398-3

Noetel, M., Sanders, T., Gallardo-Gómez, D., Taylor, P., del Pozo Cruz, B., van den Hoek, D., Smith, J. J., Mahoney, J., Spathis, J., Moresi, M., Pagano, R., Pagano, L., Vasconcellos, R., Arnott, H., Varley, B., Parker, P., Biddle, S., & Lonsdale, C. (2024). Effect of exercise for depression: Systematic review and network meta-analysis of randomised controlled trials. BMJ, 384, e075847. https://doi.org/10.1136/bmj-2023-075847

Singh, B., Bennett, H., Miatke, A., Dumuid, D., Curtis, R., Ferguson, T., Brinsley, J., Szeto, K., Petersen, J. M., Gough, C., Eglitis, E., Simpson, C. E. M., Ekegren, C. L., Smith, A. E., Erickson, K. I., & Maher, C. (2025). Effectiveness of exercise for improving cognition, memory and executive function: A systematic umbrella review and meta-meta-analysis. British Journal of Sports Medicine, 59(12), 866–876. https://doi.org/10.1136/bjsports-2024-108589

Wang, Y.-H., Zhou, H.-H., Luo, Q., & Cui, S. (2022). The effect of physical exercise on circulating brain-derived neurotrophic factor in healthy subjects: A meta-analysis of randomized controlled trials. Brain and Behavior, 12(4), e2544. https://doi.org/10.1002/brb3.2544