Concussion and Exercise: The Importance of Exercise in Recovery

= Authors =

Aarchie Soni, BHSc Health Sciences Candidate 2024, McMaster University
Jenni Diamond, OT Reg. (Ont.)


Recovery after Concussion

A concussion is a type of traumatic brain injury, occurring from an impact to the head or body and resulting in concussion symptoms. Spontaneous recovery from a sports-related concussion typically occurs within 2-3 weeks, however, up to 30% of patients may have longer recovery times.1 You can read more about concussions in general on our previous blog post here. Guidelines for recovery after concussions and symptom management have changed quite a bit in the past few years, especially when it comes to exercise and concussions.

Previous Guidelines: “Rest is Best”

Previous guidelines for recovery after concussion favoured a “rest is best” approach, partially driven by the finding that excessive activity soon after concussion interfered with and prolonged recovery. As such, past consensus-based recommendations emphasized physical and cognitive rest until complete symptom resolution before training or sport.2

However, it is now understood that prolonged rest is not particularly effective after a concussion. In fact, prolonged rest and social isolation may exacerbate symptoms and delay recovery.2 Instead, moderate levels of prescribed physical activity by your healthcare provider may be beneficial in recovery after concussion.1

The most recent Concussion in Sport Guidelines statement in 2016 also acknowledges that there is insufficient evidence to support the effectiveness of prescribing complete rest. Instead, it is recommended that a brief rest period of 1-2 days after injury be followed by a gradual and progressive sub-threshold (which is at levels below the onset or worsening of concussion symptoms) return to activity, determined in consultation with your physician.3


…it is recommended that a brief rest period of 1-2 days after injury be followed by a gradual and progressive sub-threshold return to activity…


Current guidelines: “Exercise is Medicine”

Physical exercise within days of a TBI has been shown to assist in recovery in several ways. A way in which exercise may assist in recovery after concussion includes the induction of factors that promote neuron growth and repair such as brain-derived neurotrophic factor (BDNF).2

Some resulting effects of exercise on recovery may include:


…exercise may … [induce] factors that promote neuron growth and repair such as brain-derived neurotrophic factor…


What type of exercise works best?

Concussion can often cause exercise intolerance, which is the inability to exercise to the level predicted for one’s age and fitness due to an increase in concussion symptoms. The cause of exercise intolerance is unknown, but it is hypothesised that this may occur due to changes in the autonomic nervous system, cardiac stroke volume, and blood flow to the brain.1 Symptom worsening secondary to exercise may also deter patients from exercise.2

Research has shown individualized subthreshold aerobic exercise to be an effective intervention for recovery. Subthreshold exercise is exercise at an intensity that does not exacerbate symptoms. Walking, running, and stationary cycling are all examples of aerobic exercise that can be done to support recovery.7

Research done on this particular intervention has shown that subsymptom aerobic exercise treatments prescribed in the first week after concussion safely speeds recovery.7 Aerobic exercise has also shown to increase factors for growth such as BDNF as early as 5 weeks after starting training.2


…research has shown that exercise can be thought of as an effective medicine to help in recovery after concussion.


So, research has shown that exercise can be thought of as an effective medicine to help in recovery after concussion. However—as is the case with any other medicine—it is important to consult with your healthcare provider to determine the appropriate dosage for you. Excessive or intense exercise can potentially be harmful, but by working with your healthcare provider to develop a personalized training regimen, you can get on the road-to-recovery faster! For more information on concussions, interventions, and current research, be sure to check our past blog posts.



  1. Bezherano I, Haider MN, Willer BS, Leddy JJ. Practical Management: Prescribing Subsymptom Threshold Aerobic Exercise for Sport-Related Concussion in the Outpatient Setting. Clin J Sport Med. 2021 Sep 1;31(5):465–8.
  2. Leddy JJ, Haider MN, Ellis M, Willer BS. Exercise is Medicine for Concussion. Curr Sports Med Rep. 2018 Aug;17(8):262–70.
  3. McCrory P, Meeuwisse W, Dvorak J, Aubry M, Bailes J, Broglio S, et al. Consensus statement on concussion in sport—the 5th international conference on concussion in sport held in Berlin, October 2016. Br J Sports Med [Internet]. 2017 Jun 1 [cited 2022 Dec 31];51(11):838–47. Available from:
  4. Itoh T, Imano M, Nishida S, Tsubaki M, Hashimoto S, Ito A, et al. Exercise increases neural stem cell proliferation surrounding the area of damage following rat traumatic brain injury. J Neural Transm [Internet]. 2011 Feb 1 [cited 2022 Dec 31];118(2):193–202. Available from:
  5. Itoh T, Imano M, Nishida S, Tsubaki M, Hashimoto S, Ito A, et al. Exercise inhibits neuronal apoptosis and improves cerebral function following rat traumatic brain injury. J Neural Transm (Vienna). 2011 Sep;118(9):1263–72.
  6. Seo TB, Kim BK, Ko IG, Kim DH, Shin MS, Kim CJ, et al. Effect of treadmill exercise on Purkinje cell loss and astrocytic reaction in the cerebellum after traumatic brain injury. Neuroscience Letters [Internet]. 2010 Sep 13 [cited 2022 Dec 31];481(3):178–82. Available from:
  7. Leddy JJ, Haider MN, Ellis MJ, Mannix R, Darling SR, Freitas MS, et al. Early Subthreshold Aerobic Exercise for Sport-Related Concussion: A Randomized Clinical Trial. JAMA Pediatrics [Internet]. 2019 Apr 1 [cited 2022 Dec 31];173(4):319–25. Available from:



Concussion and Dietary Supplements: How to Feed your Recovering Brain

= Authors =

Laura Diamond, MSc Global Health Student

Gabi Kaplan, Student Occupational Therapist

Jenni Diamond, OT Reg. (Ont.)

Evan Cole Lewis, MD


What is a concussion?

A concussion is a mild traumatic brain injury (mTBI) that affects brain function. Symptoms include, but are not limited to:

The effects of concussion can last for several days, weeks, or months, taking a large toll on day-to-day living and activities (1).

How can my diet and nutrients affect my concussion?

For many years, scientists studied the role of pharmaceutical drugs as potential treatments for concussions. To date, these pharmaceutical agents have had minimal success in treating TBI (2).

Research has revealed that following brain injury, a wide range of changes occur in both the brain and body – these include changes in nutritional status. Scientists believe that these nutrient deficiencies may worsen concussion symptoms and prolong recovery (2).

Treating concussions with vitamins, nutrients, and minerals has great potential as an effective treatment for concussions. While still largely understudied in humans, recent animal research has shown promising results for supplementing basic nutrition to improve brain injury recovery. These nutritionally-based therapies (or “nutraceuticals”) are FDA approved and have few interactions with other drugs, making them deal candidates for concussion therapy (2).


Research has revealed that following brain injury, a wide range of changes occur in both the brain and body – these include changes in nutritional status.


Which nutraceuticals may help me?

Research reveals Vitamins B2, B3, C, D, and E may have a role in the treatment of concussion symptoms, either alone or in conjunction with other supplements or pharmacological treatments (2; 4; 8; 9).


… vitamins and supplements found in our everyday foods have the potential to aid in the prevention, treatment and overall recovery from concussion.


It’s clear that many vitamins and supplements found in our everyday foods have the potential to aid in the prevention, treatment and overall recovery from concussion.

At present, the majority of the available data is limited to animal studies. Therefore, the FDA has issued warnings against the promotion of dietary supplements in concussion treatment (10). Additionally, many of these supplements are not subject to the safety/quality standards of the FDA so the exact potency of any commercial product may not reflect what is printed on the label (8). Until more human studies are completed, the role and effects of these alternative treatment options remain unclear.


Many supplements are not subject to the safety/quality standards of the FDA so the exact potency of any commercial product may not reflect what is printed on the label.


Meanwhile, it is important to be aware that “rapid, thorough evaluation by a health care provider, followed by rest, sleep, and light exercise, are essential for full recovery from a concussion” (10). And, of course, eating balanced, nutritious meals can ensure your brain receives a wide variety of the important vitamins and nutrients listed above.

So if you or a loved one are suffering from a brain injury, don’t forget about the role nutrients and vitamins may play in your recovery. Be sure to ask your doctor which of these supplements are right for you! And of course, stay tuned for more research…




Thanks to Keren Chen, Neurology Centre of Toronto’s stellar nutritionist, for comments and review.



  1. MFMER. (2018). Concussion. Retrieved from
  2. Haar, C. V., Peterson, T. C., Martens, K. M., & Hoane, M. R. (2016). Vitamins and nutrients as primary treatments in experimental brain injury: Clinical implications for nutraceutical therapies. Brain research, 1640, 114-129.
  3. ODS (2018). Riboflavin. Retrieved from
  4. Hoane, M.R. et al. Treatment with vitamin B3 improves functional recovery and reduces GFAP expression following traumatic brain injury in rats. J Neurotrauma. 2003 Nov;20(11):1189-99.
  5. ODS (2018). Vitamin C. Retrieved from
  6. ODS (2018). Vitamin D. Retrieved from
  7. ODS (2018). Vitamin E. Retrieved from
  8. Ashbaugh, A., & McGrew, C. (2016). The role of nutritional supplements in sports concussion treatment. Current sports medicine reports, 15(1), 16-19.
  9. Hoane, M. R., Wolyniak, J. G., & Akstulewicz, S. L. (2005). Administration of riboflavin improves behavioral outcome and reduces edema formation and glial fibrillary acidic protein expression after traumatic brain injury. Journal of neurotrauma, 22(10), 1112-1122.
  10. Hume, A. L. (2018). FDA warns companies against promoting dietary supplements for concussions. Pharmacy Today, 24(9), 16.
  11. ODS (2018). Omega-3 Fatty Acids. Retrieved from
  12. NCCIH (2018). Coenzyme Q10. Retrieved from
  13. Kalayci, M., Unal, M. M., Gul, S., Acikgoz, S., Kandemir, N., Hanci, V., … & Acikgoz, B. (2011). Effect of Coenzyme Q 10 on ischemia and neuronal damage in an experimental traumatic brain-injury model in rats. BMC neuroscience, 12(1), 75.
  14. ODS (2018). Magnesium. Retrieved from

How does COVID19 Affect Epilepsy?

= Authors =

Christina Muratore, Epilepsy Toronto

Geoff Bobb, Epilepsy Toronto

Mackenzie Muldoon, Epilepsy Toronto

Ivana Yau, NCT & SickKids

Evan Cole Lewis, NCT


Epilepsy & COVID-19

Recognizing that people had questions about how COVID19 may or may not affect epilepsy, NCT and Epilepsy Toronto teamed up to create a helpful resource.

A list of frequently asked questions were gathered together and addressed.

If you have further questions, don’t hesitate to reach out to Epilepsy Toronto or Neurology Centre of Toronto.

Stay safe everyone and remember to abide by social distancing standards as these are our best way to contain the spread of COVID19.

Cannabis: The Next Treatment for Epilepsy?

=== Jordan J. Ghassemian, Rozalba Luka, MD and Evan Cole Lewis, MD, FRCPC ===

Nearly 90,000 Ontarians have epilepsy.

There are medications that effectively control seizures in about 70% of people. But 30% of people do not respond to drugs and have drug-resistant epilepsy.

In addition to increased mortality rates, those with drug-resistant epilepsy report having a lower quality of life and struggles with isolation, loss or lack of employment and independence, cognitive and memory impairments, and depression. Children with epilepsy have a higher relative risk of intellectual disabilities, learning disabilities, and emotional and nervous difficulties.

[Credit: Ontario Brain Institute]

The initial treatment for seizures in epilepsy is medication. About 30% of individuals will be drug-resistant, which means that their seizures do not stop after trying two medications. Once an individual requires a third medication to treat seizures, the chance of becoming seizure-free is less than 3%. This is why neurologists and scientists strive to develop better anti-seizure medications. Promising research is currently underway regarding Cannabidiol (CBD), a major component found in the Cannabis/Marijuana plant.

The cannabis plant has two major components:

  1. ∆9-tetrahydrocannabinol (THC)
  2. Cannabidiol (CBD)

THC is primarily responsible for the psychoactive properties (i.e. having a significant effect on the mental state), while CBD appears to have anti-seizure properties. The ideal treatment would be a plant that contains high CBD and low THC.

Does CBD reduce seizures in epilepsy?

CBD was shown to reduce seizures in animals (1, 2), which led to further investigations using CBD in humans with epilepsy. In one study, researchers tested the effect of oral CBD in patients with drug-resistant epilepsy (3). Convulsive seizures (i.e. seizures which appear as body shaking) were reduced by 50%. Other studies with CBD have also demonstrated similar effects in other types of epilepsy, such as Dravet syndrome (4, 5).

Can CBD be used with other anti-seizure medications?

Using CBD to reduce seizures is not straight-forward, despite what many mainstream providers may claim. The use of CBD requires guidance by an expert to determine the correct dose, and any interactions with other medications.

CBD has been shown to increase blood levels of the following anti-seizure medications (6):

It is strongly recommended that patients discuss starting CBD with their neurologists before using it to treat their epilepsy.

Are there any adverse effects associated with using CBD?

Adverse effects associated with CBD treatment were primarily observed to be more physical than behavioral in nature. Main side effects included:

Researchers also observed that patients who were taking higher doses of CBD per day were more likely to report diarrhea or related side-effects, including weight loss (3). However, most adverse effects were mild and lasted for only a brief period of time.

Overall, research into the effectiveness, safety, and side effects of CBD has made significant headway, but there is still more work to be done. As the medical community continues to explore CBD as a treatment for epilepsy, the potential for it to be our next treatment for epilepsy seems promising.



1. Jones, N. A., Glyn, S. E., Akiyama, S., Hill, T. D., Hill, A. J., Weston, S. E., . . . Williams, C. M. (2012). Cannabidiol exerts anti-convulsant effects in animal models of temporal lobe and partial seizures. Seizure, 21(5), 344-352. doi:10.1016/j.seizure.2012.03.001

2. Hill, T. D., Cascio, M., Romano, B., Duncan, M., Pertwee, R. G., Williams, C. M., . . . Hill, A. J. (2013). Cannabidivarin-rich cannabis extracts are anticonvulsant in mouse and rat via a CB1receptor-independent mechanism. British Journal of Pharmacology, 170(3), 679-692. doi:10.1111/bph.12321

3. Devinsky, O., Marsh, E., Friedman, D., Thiele, E., Laux, L., Sullivan, J., . . . Cilio, M. R. (2016). Cannabidiol in patients with treatment-resistant epilepsy: An open-label interventional trial. The Lancet Neurology, 15(3), 270-278. doi:10.1016/S1474-4422(15)00379-8

4. Maa, E., & Figi, P. (2014). The case for medical marijuana in epilepsy. Epilepsia, 55(6), 783-786. doi:10.1111/epi.12610

5. Devinsky, O., Cross, H., Laux, L., Marsh, E., Miller, I., Nabbout, R., . . . Wright, S. (2017). Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome. New England Journal of Medicine, 377(7), 699-700. doi:10.1056/nejmc1708349

6. Gaston, T. E., Bebin, M., Cutter, R., Liu, & Szaflarski, J. P. (2017). Interactions between cannabidiol and commonly used antiepileptic drugs. Epilepsia, 58(9), 1586-1592. doi:10.1111/epi.13852