Exercise and BDNF: How Physical Activity Supports Brain Health
We’ve all heard that exercise is good for our health. It has been associated with benefits for almost every system in the body, including improved cardiovascular health, increased bone mineral density, and decreased risk of stroke, diabetes, and some cancers. Exercise is also well known for its relationship with improved mood and decreased rates of depression.
But what do we know about how exercise impacts the brain?
Research has associated regular physical activity with improvements in cognitive function, including memory, attention, executive functioning, and problem solving. Exercise is also associated with changes in blood flow and vascularization in the brain, as well as changes in areas involved in learning and memory. Research has also explored the relationship between exercise, neurogenesis, and neuroplasticity—the brain's ability to adapt and change.
So how might exercise promote some of these positive changes in the brain?
One important piece of the puzzle is a growth factor called brain-derived neurotrophic factor, or BDNF.
What Is BDNF?
BDNF is a protein that supports the health, survival, and functioning of neurons, or brain cells. It plays an important role in processes involved in learning, memory, and neuroplasticity.
Research has found that exercise can influence BDNF and other signaling pathways involved in neuronal plasticity. For example, experimental research has demonstrated that voluntary exercise increased BDNF expression and other markers involved in synaptic plasticity.
Put simply, exercise appears to give the brain some of the signals it needs to adapt, communicate, and change.
What has BDNF been associated with?
Higher BDNF levels have been associated with:
Preservation of cognitive functioning
Neuroplasticity and neuronal health
Recovery processes following injury to the central nervous system
Lower BDNF levels have also been associated in research with conditions including:
Anxiety
Major depressive disorder
Schizophrenia
Alzheimer's disease
It is important to note that these are associations, not evidence that BDNF levels alone cause or prevent these conditions. BDNF is one piece of a much larger picture of brain health.
BDNF and Traumatic Brain Injury
So what does BDNF have to do with concussion and traumatic brain injury?
Researchers have investigated whether circulating BDNF levels may be associated with the severity of traumatic brain injury and recovery.
A 2016 study by Korley and colleagues examined blood BDNF levels in people with traumatic brain injury and found that very low BDNF levels on the day of injury were associated with greater odds of incomplete recovery at six months. The researchers also found differences in BDNF levels across TBI severity groups.
These findings are interesting because they suggest that BDNF may have diagnostic and prognostic value following traumatic brain injury. However, this research does not mean that simply increasing BDNF will prevent complications or guarantee a better recovery.
We still have much to learn about exactly how BDNF interacts with the many other processes involved in brain injury and recovery.
So, Where Does Exercise Come In?
This is where things get interesting.
We know that exercise can influence BDNF and other pathways involved in neuroplasticity. We also know that appropriately prescribed physical activity is an important part of modern concussion rehabilitation. Current concussion guidance recommends relative rest rather than strict rest during the first 24–48 hours after injury, followed by a gradual increase in physical activity as tolerated.
That does not mean that someone with a concussion should immediately jump into a high-intensity workout.
The type, intensity, and timing of exercise matter. For someone recovering from a concussion, exercise should be introduced in a way that is appropriate for their symptoms, exercise tolerance, and stage of recovery. When symptoms are provoked beyond what is considered mild and brief, activity may need to be modified.
This is one reason individualized concussion rehabilitation is so important.
Learn more about Physical Activity After Concussion: When and How Much?
Exercise for the Win!
There is a lot we still don't know about BDNF and exactly how it contributes to recovery after concussion and other forms of traumatic brain injury.
What we do know is that exercise has wide-ranging benefits for physical and brain health, and current concussion research supports appropriately dosed physical activity as an important component of recovery.
At Colorado Concussion Clinic, we are huge proponents of getting people moving—but appropriately and safely. The goal isn't to push through symptoms or do as much exercise as possible. It's to determine what your body and brain can tolerate and gradually build from there.
References
Korley FK, Diaz-Arrastia R, Wu AH, et al. Circulating Brain-Derived Neurotrophic Factor Has Diagnostic and Prognostic Value in Traumatic Brain Injury. Journal of Neurotrauma. 2016;33(2):215-225. doi:10.1089/neu.2015.3949.
Gómez-Pinilla F, Ying Z, Roy RR, Molteni R, Edgerton VR. Voluntary exercise induces a BDNF-mediated mechanism that promotes neuroplasticity. Journal of Neurophysiology. 2002;88(5):2187-2195. doi:10.1152/jn.00152.2002.
Patricios J, Schneider KJ, Dvořák J, et al. Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport—Amsterdam, October 2022. British Journal of Sports Medicine. 2023;57(11):695-711. doi:10.1136/bjsports-2023-106898.
Originally published March 16, 2021. Updated August 2026.
This article has been updated for clarity, readability, and website accessibility.