Why Is Exercise Good for Your Brain? What Research Shows

Why is exercise good for your brain, and how strong is the evidence? Studies suggest various lifestyle factors can influence overall health, but the relationship between exercise and the brain is still uncertain, according to research in PLOS One. A review of 24 meta-analyses on physical exercise and cognition, published in Nature Human Behaviour, reported that stronger causal evidence is required before we can definitively conclude that exercise improves our brain health.

Gaining a better understanding of this connection is particularly important for older patients. As patients age into their senior years, they become more vulnerable to cognitive decline, as noted in the British Medical Bulletin. If exercise does have a positive impact on brain health, then consistent physical activity has the potential to promote healthy cognitive aging and help protect against cognitive decline, according to Frontiers in Aging Neuroscience. It's why Creyos was used to measure cognitive outcomes in the Brain and Body Study.

This article explores the relationship between exercise and the brain by examining various types of workouts and how they may affect cognitive and mental health. We also explore ways to measure the impact of exercise on brain health with computerized cognitive tests to determine which lifestyle interventions can truly improve cognition.

How does exercise affect the brain?

Research has long established that exercise is of great benefit for physiological health, as a review in BMC Public Health notes, but the results are less clear when pinpointing exactly which aspects of brain health are affected.

That's why it's vital that more research is conducted, so that patients understand the ways in which exercise can help reduce the symptoms of cognitive decline or if other forms of preventive treatment might also be useful.

Read more: How to Prevent Dementia: 12 Modifiable Risk Factors

Health contexts for recommending exercise

Educating patients on how exercise affects their health is a routine part of physical and cognitive health checkups. By discussing the importance of various health strategies, primary care physicians (PCPs) can help patients form realistic expectations on how lifestyle factors impact cognition.

Preventive care

When it comes to preventive care, studies suggest that exercise has health benefits for the brain and cognition throughout life, according to research in Nature Reviews Neuroscience. The research concludes that aerobic exercise and fitness training help improve neurogenesis, develop blood vessels, and form synaptic connections in the brain.

Because many interconnected factors may affect brain health, it’s difficult to isolate precisely how exercise impacts cognitive and psychological health. Genetic and environmental factors can also shape a patient’s cognitive and mental health, but lifestyle factors are considered “modifiable risk factors” that are within a patient’s ability to influence.

So there are concerted efforts within healthcare to encourage exercise as a preventive strategy in the context of cardiovascular, neurodegenerative, mental health, and chronic conditions, as outlined in the American Journal of Lifestyle Medicine. More research is required to determine exactly how physical activity can benefit the brain.

Dementia prevention and management

While exercise is one of the 12 modifiable risk factors for dementia, research suggests that the effects of physical activity on dementia prevention and management aren't as clear cut as they may seem. For patients with dementia who need to manage the disease, a systematic review in the British Journal of Sports Medicine on exercise training and older adults with different kinds of dementia indicates that the findings of 48 different studies aren't conclusive.

While exercise did benefit the cognitive function of older adults with dementia, the review suggests that more research needs to be conducted, especially when it comes to determining if the effects of exercise differ depending on the type of dementia a patient has.

Similarly, another review in Frontiers in Physiology suggests that exercise as a form of dementia prevention varies depending on the individual. As such, even though exercise is a modifiable risk factor for dementia, its efficacy may depend on the type of dementia a patient has and whether that patient responds well to exercise in the first place.

Mental health

Exercise and staying physically healthy can be effective methods for managing mental health conditions like depression, stress, and anxiety. Research indicates that physical activity reduces inflammation, which can contribute to better health outcomes for patients with mood disorders.

However, exercise may not be the most optimal intervention for every patient. A study on the effects of exercise during the COVID-19 lockdowns suggests that people with lower tolerance for feelings of anxiety and uncertainty can become addicted to exercise under specific conditions, according to research in Maturitas.

While exercise isn't meant to be a cure-all for mental health disorders, it can serve as a viable supplementary option alongside traditional treatments, offering a non-pharmacological approach to enhancing overall mental wellness.

Interestingly, the Brain and Body Study found that video gaming during the COVID-19 lockdown generally had a positive influence on participants’ wellbeing and mental health, as reported in Games and Culture.

Some of the attributes of video games that potentially contributed to these results included:

• Socialization
• Being exposed to new environments (even if those settings were virtual)
• Experiencing novelty or nostalgia
• Benefitting from cognitive stimulation

In addition to the physical nature of exercise, the cognitive and mental health benefits may be similarly tied to the above characteristics shared by video games. This research highlights how different interventions may be appropriate to support brain health depending on the individual and their context.

Pain care

Can chronic pain negatively impact cognition over time? A review on chronic pain in older adults, published in Frontiers in Human Neuroscience, suggests that this is a possibility, with evidence that indicates pain can aggravate memory loss for patients with Alzheimer's disease or trigger motor symptoms among people with Parkinson's disease.

But whether managing pain through exercise can actually help reduce or slow the effects of neurodegenerative diseases is still uncertain. Even exercise as a tool to manage chronic neuropathic pain has inconsistent results. As indicated in a review in Sports Medicine - Open, aerobic exercise training led to reductions in pain interference but had no effect on pain intensity. In other words, exercise may reduce some, but not all, pain measures.

In contrast, a systematic review in BMC Musculoskeletal Disorders on the effects of exercise on individuals with musculoskeletal pain is more positive, but it also acknowledges that more research needs to be done on whether pain reduction has an effect on patient outcomes and quality of life.

Exercise as a form of pain management may be able to help reduce certain chronic pains in older patients with cognitive conditions, and potentially support mental and cognitive wellbeing at the same time. Of course, more detailed research is needed into the complex relationship between the brain and the body.

Cardiovascular health

The connection between cardiovascular health and physical activity is thoroughly documented. In addition, hypertension, caused by high blood pressure damaging blood vessels, can lead to cognitive impairment and dementia, according to Frontiers in Neurology.

As such, hypertension is a modifiable risk factor for dementia which can be reduced through lifestyle changes and treatments targeted at improving cardiovascular health, such as exercise.

Clinicians have to determine on a per-patient basis whether medications (such as antihypertensive treatments for cardiovascular disease), lifestyle changes, or a combination of both are appropriate for a patient. While more research is needed into precisely what kind of cardiovascular treatment is optimal for brain health, there is potential benefit to introducing exercise for patients with comorbid heart and brain health concerns.

Diabetes prevention and management

Type 2 diabetes is another risk factor for dementia, although its association with cognitive dysfunction is less well-known. Exercise as a form of prevention and treatment for patients with diabetes, alongside dietary restrictions, can be an effective method of glycemic control by enhancing insulin sensitivity and improving glucose uptake, which reduces the risk of insulin resistance.

These benefits extend to cognitive function, as consistent exercise helps prevent elevated blood sugar levels, which can damage brain blood vessels and nerves and lead to cognitive impairment, according to research on the mechanisms linking cognitive impairment and diabetes. However, more research needs to be done when considering other factors alongside exercise, such as diet, medication, and genetics.

ON-DEMAND WEBINAR

Exploring Brain Health: Recent Advances and Future Frontiers

Types of exercise and their connection to cognitive function

While physical activity is beneficial for physiological health, there is also evidence that certain exercise interventions may support cognitive and mental health, particularly in older adults.

Aerobic exercise

Often referred to as "cardio," aerobic exercise improves cardiovascular endurance and fitness. It involves continuous, rhythmic activities like walking, running, cycling, swimming, and dancing.

But does it affect the brain? A meta-analysis in NeuroImage indicates that aerobic exercise is directly tied to hippocampal and gray matter volume. However, the meta-analysis found no evidence that exercise changes total hippocampal volume, only that it helps retain left hippocampal volume in healthy older adults.

The review also notes that there was some risk of bias among included studies, which means more research is required to better understand how aerobic exercise and brain health are connected.

Weight training and resistance training

Also known as strength training, weight training is performed with a specific number of sets and repetitions, where the patient lifts, lowers, or holds a weight against gravity. Typically, regular weight training can help build and maintain muscle mass, but there may also be associations between exercise, processing speed, and executive function.

While there is some overlap between resistance training and weight training, this kind of exercise is designed to improve muscle strength and endurance by working against an external force of resistance. This external force can come from various sources, including free weights (dumbbells and barbells), resistance bands, weight machines, or even body weight.

Like aerobic exercise, resistance training may be linked to hippocampus volume and brain plasticity. A study of hippocampal plasticity and resistance training for older adults vulnerable to Alzheimer's disease (AD), published in NeuroImage: Clinical, shows that frequent resistance exercise helped prevent hippocampal atrophy.

The results suggest resistance training can act as a kind of neuroprotection, helping to prevent atrophy in brain areas vulnerable to AD. More research is needed to find out how long-lived this neuroprotection actually is, and whether it's significant enough to delay cognitive decline.

A separate study in GeroScience examined the cognitive performance of participants aged 85 to 99 years old and found that those who included weight training in their workouts saw improvements in their cognitive test scores. In this case, it should be noted that performing the actual weight training exercises was self-reported by participants, lending them a degree of subjectivity.

Other meta-reviews, including one in Psychological Research, have supported that weight training and resistance training show positive effects on cognition, but more research is needed to further isolate the mechanisms at play.

Answering patient questions: why is exercise good for your brain?

While it can be challenging to talk to patients about cognitive health care, linking the possible benefits of exercise to brain health is one way to introduce the topic. How a PCP guides the conversation depends on their individual practice, but there are a few general questions that patients may have, including the following.

What are the 10 benefits of exercise on the brain?

With more research into the connection between the body and brain, exercise has the potential to offer a range of cognitive and mental health benefits in the following areas:

1. Improved mood: Exercise can play a role in mental health and well-being for some people, helping to reduce symptoms of depression and anxiety, according to research in Cureus.
2. Reduced stress: Some patients may be able to use physical activity as a form of stress management, as reported in Psychology & Health.
3. Better sleep: Regular exercise may improve sleep quality in certain patients and help manage sleep disorders like insomnia, according to Frontiers in Psychiatry.
4. Enhanced brain plasticity: Although the research is still ongoing, there is some evidence in Brain Sciences that aerobic exercise promotes brain plasticity in people with mild cognitive impairment.
5. Preserved brain volume: There is evidence, published in the Journals of Gerontology, that performing a certain amount of exercise per week can help prevent brain atrophy in some patients, preserving brain volume.
6. Improved focus and attention: Physical activity has the potential to improve temporal impulsivity in adults with attention deficit hyperactivity disorder (ADHD), according to Behavioral Sciences; however, these effects may not be universal to all patients with ADHD.
7. Increased neurogenesis: Physical activity may be able to promote the growth of new neurons by increasing the production of endocrines that stimulate neurogenesis in the hippocampus, according to Frontiers in Endocrinology.
8. Slowed cognitive decline: Research in Frontiers in Neuroscience suggests regular exercise likely drives metabolic activity, cerebrovascular mechanisms, and neuroplasticity throughout the brain, all of which can potentially slow cognitive decline in patients at risk for dementia, to a certain degree.
9. Improved executive function: Studies suggest that exercise generally has a positive effect on executive function, and research is ongoing to pinpoint specific facets of cognition that may be influenced by physical activity, according to the European Journal of Sport Science.
10. Social interaction opportunities: Group exercise or team sports can boost social interaction opportunities. There is a clear relationship between social interaction and cognitive function, according to a review in Systematic Reviews.

Can exercise rewire your brain?

It's possible that exercise may be able to reshape the brain, but research in this area is still underway to determine the concrete connections, as noted in Molecular Neurobiology. Physical wellness may be used as a form of brain care in certain circumstances, but whether exercise can actually rewire the brain, and to what degree, still requires more research.

Which exercise is best for the brain?

There is no optimal exercise for brain health at the moment, because the exact nature of how each type of exercise affects the brain still needs to be determined. However, various exercises have the potential to benefit the brain in different ways:

• Resistance exercises may be able to preserve brain volume, according to Journals of Gerontology research.
• Aerobic exercises may be able to improve cognitive function, according to a preprint on bioRxiv.
• Yoga may have strong mental health benefits, according to Complementary Therapies in Medicine.

What happens to your brain when you don't exercise?

Research is still unclear about whether a sedentary lifestyle negatively affects brain health, although it may seem that way. A systematic review of sedentary behaviors and their impact on cognitive decline in older adults, published in Aging Clinical and Experimental Research, showed that there is still a lack of clarity in this area. For example, it can be difficult to determine if sedentary time has an effect independent from exercise.

Similarly, a study in BMC Public Health on how sedentary time affects the cognition of adolescents found that their planning skills were linked with sedentary time, while memory and executive functions remained the same.

How can clinicians measure the impact of exercise on brain health?

Without the right tools, PCPs can't accurately assess changes in a patient's brain function and mental well-being, and are forced to rely on more subjective measures instead. But there are cognitive healthcare solutions that can more precisely and objectively track how exercise and lifestyle interventions affect a patient's cognitive health.

Using scientifically-backed technology, Creyos offers a sophisticated platform for computerized, standardized cognitive function tests. Creyos allows PCPs to test cognitive performance through online cognitive tasks, enabling users to monitor changes in memory, attention, and other cognitive domains resulting from regular physical activity. PCPs can even track a patient’s psychological symptoms through self-report behavioral health questionnaires, such as the PHQ-9 and GAD-7, allowing PCPs to gather more accurate diagnostic and longitudinal data and deliver a patient-centered approach to care.

With Creyos, the complex relationship between exercise and the brain can be monitored with greater detail and insight, leading to more informed decisions and personalized approaches to enhancing cognitive well-being while also playing a part in whole person care.

Making exercise a part of brain health care

While more research needs to be done to determine the exact ways in which exercise may benefit cognitive function and mental health, the positive effects of physical activity on brain and body health are firmly established.

Given the complex links between physical activity and brain health, exercise is not a one-size-fits all intervention. For the patients who can benefit, a personalized and balanced exercise routine that includes aerobic, weight training, and resistance training, alongside tools like Creyos to capture objective measurements, has the potential to help some patients improve their brain health.

Reviewed by Sydni Paleczny, Staff Scientist at Creyos

Sydni earned her MSc in Neurosciences at Western University under Dr. Adrian Owen. Her research explores neuropsychological outcomes after cardiac surgery, with interests in cognitive neuroscience, critical care, and brain health. At Creyos, she supports scientific validity, health technology, and ongoing research.