Exercise After a Concussion: Why It’s Important
Most people are aware of the general benefits of aerobic exercise: Regular exercise helps prevent or manage major health problems such as heart disease, diabetes, and obesity. It lowers blood pressure, increase muscle mass and improves mental health. But aerobic exercise also helps brain function by increasing blood flow to the brain, giving the brain oxygen required for optimal function. Blood flow also stimulates the brain to produce chemicals that stimulate cell growth and improve neuroplasticity.
For example, the brain-derived neurotrophic factor (BDNF) is a protein that promotes the growth of neurons and increases synaptic plasticity, which improves communication between cells in the brain. Studies show that every time you exercise, your body produces this protein. Regular exercise increases its production and benefits even more. This post-exercise cognitive boost continues for hours after exercise and is an important factor in healing from brain trauma and in improving cognitive abilities. In a nutshell, you need to exercise so that your brain can obtain and use these chemicals to heal.
This means that whether you’re an athlete recovering from a sport-related concussion or someone whose normal activity level is lower, exercise will be an important part of your recovery. In fact, exercise is critical to your recovery and returning to what you need, want, and love to do!
I was told not to do anything after my concussion. Is that correct?
Until recently, most doctors advised patients with a concussion to rest completely from mental and physical activities, until concussion symptoms disappeared. This practice, known as cocooning, could last from several days to several weeks. Unfortunately for some patients, their symptoms lasted much longer — months or even years. The isolation they endured led to an increase in depression and anxiety, and it actually slowed their recovery time.
Studies now show that complete rest lasting longer than 2 days can actually lead to worse outcomes. Moderate physical activity within the first week of a concussion, even on the first or second day, actually speeds recovery time and lessens the chances of developing post-concussion syndrome. Mild, sensible exercise will produce those chemicals that your brain needs to begin the healing process, and staying connected to people will help your mental health and attitude.
What kinds of exercise can I do right after a concussion?
You need to use some common sense when you first return to exercise after a concussion. Don’t do anything that puts you at risk for another concussion. Avoid activities that cause your head or body to jolt, such as contact sports, running, and jumping.
So, what can you do? You want to do mild exercise that increases your heart rate without drastically increasing your symptoms. Riding a stationary exercise bike or working out in a pool are good options. Walking at a moderate pace is another good activity. You could also try using an elliptical machine.
If your symptoms are still really unpleasant, you might try to do some strength training that is intense enough to raise the heart rate slightly. Other activities that might work are Pilates, leg lifts, squats, and lunges.
It’s OK to exercise even though you aren’t feeling great yet. If you find you’ve pushed yourself too far and you experience drastically worse symptoms, back off a little next time and try again. The important thing is to keep exercising. Your brain needs that post-exercise cognitive boost to heal.
Keep in mind that even exercising for 5 minutes, if that is what you can tolerate, is absolutely worth doing. With practice, you can turn those 5 minutes into 7 minutes, and those into 10 minutes, and so forth. Continue gradually increasing how long you exercise until you hit a good number.
Causes of Post Concussion Syndrome Exercise Intolerance
What if it’s been a few weeks since your concussion and you’re still experiencing symptoms? Maybe you feel fine until you try to exercise, and then symptoms come back. Or, you might feel OK while you’re exercising, but you feel terrible for hours afterwards.
Exercise intolerance is a common component of post-concussion syndrome and includes typical concussion symptoms such as headaches, dizziness, fatigue, and brain fog during or after exercise. The symptoms are sometimes so alarming or unpleasant that people who experience them tend to avoid exercise. However, recent studies show this only prolongs recovery time.
In addition, not exercising can worsen the condition. We all know that when we don’t exercise, we lose muscle strength and our endurance decreases. Similarly, if someone with post-concussion exercise intolerance doesn’t exercise because of the symptoms they are experiencing, it causes the damaged areas in their brains that govern those processes to malfunction even more. So, the longer a person goes without exercising, the worse their symptoms might become.
Post-concussion exercise intolerance can be caused by any or all of the following:
- Autonomic nervous system dysfunction
- Cerebral autoregulation
- Vision problems
- Vestibular problems.
It’s possible for patients to have all of these problems since mild traumatic brain injuries often affect more than one area of the brain. We’ll examine these issues individually in the sections below. We’ll also give you some suggestions to help you figure out which one might be causing your problems and where to seek treatment.
Autonomic Nervous System Dysfunction (or Dysautonomia)
The autonomic nervous system (ANS) controls vital body mechanisms such as heart rate, blood pressure, breathing, and temperature control. The ANS is sometimes damaged as a result of a concussion or brain injury and if it’s not working correctly, you’re going to feel bad when you exercise!
The ANS is comprised of two subsystems: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
The SNS helps our bodies respond to sudden stress by producing cortisol and causing our heart rate and blood pressure to increase to meet temporary, stressful demands. It is often referred to as the “fight or flight” system.
The PNS, on the other hand, helps slow the heart rate and return our bodies to normal after a stressful episode. It is often referred to as the “rest and digest” system.
If those systems are disrupted to the point that you have trouble exercising, we refer to that as ANS dysfunction. If you experience other symptoms related to the ANS not working properly (like digestive issues and temperature dysregulation), it might be considered dysautonomia.
So why does ANS dysregulation cause problems during exercise? When you exercise, you are putting greater demands on your body. Your heart rate, blood pressure, and blood flow need to increase appropriately. When you stop exercising, they should gradually reduce to return your body to resting condition. Your brain needs this period of rest to heal.
But with exercise intolerance, the SNS is often in a near-constant state of overreacting. Your blood pressure and blood flow regulation to the brain may not work as they should. As a result of vascular dysregulation (essentially, blood flow not working properly), you might feel pressure in your head, or you might get a headache that feels like a band is tightening around your head. You might hear your heart pounding in your head, get short of breath, or feel nauseated.
Unfortunately, if you’ve stopped exercising because of these symptoms, it creates a vicious cycle that only makes things worse. Exercise is crucial to returning the ANS to normal function as well as to healing other post-concussion problems. We’ll discuss how to safely do that later in this article.
A healthy brain needs blood pressure and blood flow to be constant. Any significant change could damage brain tissue or neurons. But when you experience stress (regardless of whether it is physical, emotional, or mental), your heart rate and blood pressure change in response. Cerebral autoregulation (CA) maintains a relatively constant flow of blood throughout the brain even when your heart rate or blood pressure change.
To keep blood flow and pressure in your brain constant, CA will either constrict or dilate (e.g., make smaller or larger) the blood vessels that keep blood moving in and out of your brain. In order to do that, CA is in constant communication with your autonomic nervous system (described above).
But sometimes, the neurons which control the CA system are damaged after a brain injury. It may not respond correctly when you experience increased or decreased blood pressure. So, when you exercise, blood pressure in your brain might increase, leading to symptoms like nausea, dizziness, and headaches. If your blood pressure decreases, you might find yourself suddenly lightheaded.
Increased or decreased blood pressure are common after a brain injury. In fact, some patients experience constantly changing blood pressure in their brain, which causes chronic pain or recurring symptoms.
As with the ANS, repairing the CA system is best done via physical exercise. Exercise puts stress on the brain and forces the autoregulation system to be used. At first, you’ll likely experience symptoms when you try to exercise. But under the watchful eye of a therapist, you can help your brain learn from its failures. With the proper timing and order of therapies, patients can recover from problems with cerebral autoregulation.
Is Exercise Safe with Cerebral Autoregulation Troubles?
If you’ve been reading closely, you may wonder whether it’s really safe to exercise when your CA system isn’t functioning properly. After all, you’re exposing your brain to changes in blood pressure, right?
Exercise is the only way for the CA system to start being used again and to figure out how to do it correctly. For example, when you get surgery, then you have to rehabilitate the muscles affected. If you simply rest the muscles, they will never get back to what they were before and they might not work properly. But if you immediately tried to do everything you could before right after surgery, then you could damage even more of your body because your muscles weren’t ready for it.
It’s the same with exercise after a head injury. You have to do it in a sub-symptom level way and slowly build up to more. That way, you don’t harm yourself and you still get the benefits and improvement of exercise.
Many patients with post-concussion syndrome have vision problems that can cause symptoms that make exercise difficult or impossible, such as dizziness and headache. It might be that your eyes are having trouble focusing, or you could be experiencing problems with your peripheral vision. These problems are often overlooked and undiagnosed after a concussion or brain injury.
If you want to check to see if your problems are being caused by vision issues, try exercising with your eyes closed and see how you feel. Obviously, you need to be careful about how you do this! You could try riding a stationary bike with your eyes closed. You could also try doing some crunches or other strength training exercises that won’t put you in danger if you do them with your eyes closed. If you can do those without experiencing symptoms, your exercise intolerance might have a visual cause.
If you suspect you might have vision problems due to a concussion, it’s important that you see a specialist for an evaluation. Neuro-optometrists and neuro-ophthalmologists are doctors who are trained to diagnose and treat vision problems associated with traumatic brain injury.
The vestibular system is part of the inner ear. It works with information it receives from the eyes, muscles, and joints to help us maintain balance and spatial awareness.
If this system was damaged by a concussion or other head trauma, the brain can receive erroneous signals about the body’s position. As a result, you might experience dizziness, vertigo, nausea, head pressure, and headaches when you are moving. It can also cause excessive fatigue.
Here’s a simple test to see if vestibular issues might be causing your exercise-induced symptoms: Try an exercise with your head immobilized as much as possible. For example, you might try riding a recumbent bicycle, keeping your head as still as possible. If exercising like that doesn’t induce your symptoms, vestibular issues might be causing your problems.
Will I Ever Be Able to Exercise Again?
If you have been living with exercise intolerance and other persistent symptoms that haven’t gone away despite months or even years of rest, you may have given up hope of ever being able to exercise again. However, many people have found success with new treatment methods.
I work closely with Dr. John J. Leddy, director of the University at Buffalo Concussion Management Clinic. Dr. Leddy and his co-author, Dr. Barry Willer, published research findings that are dramatically changing the way concussions are treated, resulting in better outcomes and faster recovery. The change from the recommendation to cocoon after a concussion to beginning mild aerobic exercise almost immediately afterwards is in part a result of Dr. Leddy’s findings.
People suffering from a concussion need aerobic exercise and the chemicals produced by it in order to heal. However, that’s a problem if exercise itself causes miserable suffering.
The best way to treat exercise intolerance associated with autonomic nervous system dysfunction is to determine the point during exercise at which a person begins to feel their symptoms increase, and then to exercise for short periods just below that threshold. This is called your sub-symptom threshold.
Then, the duration and intensity of exercise gradually increases over time. Your exercise tolerance will slowly increase until you can exercise normally without negative symptoms. The ANS basically has to be retrained, and the more you use it successfully, the better it functions.
Aerobic activity is ultimately crucial to success because the key factor in this method is raising the heart rate enough to benefit the brain without drastically increasing symptoms and then gradually making adjustments over time. A precise regimen like this is going to be difficult for an untrained individual to develop.
By Charlotte Anderson MSc. PT, PhD