Many of us have heard that resting in a dark room and avoiding stimulation is the best way to recover from a concussion. However, research now shows the contrary; After a few days of rest, carefully controlled exercise improves brain recovery and function (Leddy et al. 2018).
How Does Exercise Help?
- Autonomic Function: The autonomic nervous system controls unconscious processes of the body like breathing, heart rate, and blood pressure. It is comprised of 2 branches: the activation-promoting sympathetic branch (“fight or flight”) and the relaxation-promoting parasympathetic branch (“rest and digest”). After a concussion, the sympathetic branch becomes overactive. One consequence of this is an impaired ability to regulate blood flow to the brain, which often leads to worsening symptoms with increasing levels of physical or cognitive exertion. Carefully prescribed cardiovascular exercise retrains the autonomic nervous system to have better balance between sympathetic and parasympathetic activity, improving regulation of blood flow to the brain, which reduces symptoms and ultimately improves recovery (Leddy et al. 2018).
- Neuroplasticity: Neuroplasticity refers to the ability of the brain to grow and reorganize in response to experience. In the context of a concussion, neuroplasticity reflects the ability to recover and adapt new strategies to compensate for deficiencies caused by the injury. Research shows that exercise promotes neuroplasticity through a number of mechanisms, such as by facilitating generation of new neurons, the cells of the brain (El-Sayes et al. 2019). It increases BDNF (brain-derived neurotrophic factor) which has many beneficial effects on the nervous system. It helps support the integrity of existing neurons, and encourages the development of new neurons and synapses. It is active in many parts of the brain and has a positive effect on cognition (Sleiman et al., 2016).
- Cognitive Function: The cognitive benefits of exercise relate to the concept of neuroplasticity described above. Research shows that exercise improves communication between neurons and leads to growth of brain regions involved in several domains of cognition, including memory, learning, and concentration (Etnier and Chang 2019). Additionally, exercise increases blood flow to the brain, which improves oxygen and energy delivery. Next time you have to complete a task that requires a lot of thinking, try doing a short bout of exercise (10+ minutes) before you start and see if it feels any easier.
- Sleep and Fatigue: Regular exercise promotes healthy sleep and improves cardiorespiratory fitness, which both contribute to higher energy and reduced fatigue (Hasset et al. 2017).
- Mood: Exercise releases endorphins and changes other chemical levels in the brain that promote positive mood. Exercise is also embraced by many as an effective stress reliever. In fact, exercise is considered one of the most effective treatments for many mental health conditions, including depression and anxiety (Mikkelsen et al. 2017).
Returning to Exercise
Re-integrating exercise into your life after a concussion can be difficult. Many questions arise, such as:
When is the right time for me to start exercising?
How do I know where to start? Should I just do the same exercise I was doing before the concussion?
What is the best activity for me to do?
When can I get back to my sport?
Like most things after a concussion, following a stepwise and gradual approach to exercise is the best way to ensure safety and success. Our approach combines individualized exercise progression and coaching in the context of a traditional step-wise framework for returning to athletics. When possible, we also incorporate more objective data through exertion testing to facilitate our treatment decisions.
Returning to exercise after a concussion usually involves the following stages:
1. Physical and Cognitive Rest
A period of physical and cognitive rest for the first 2-3 days after concussion is essential to allow for initial neurological recovery and avoid second impact syndrome, a potentially devastating condition in which another head injury is sustained before the first is able to heal. This period of rest gives one an opportunity to learn about the injury and how to care for it. It also allows time for medical assessment and to implement lifestyle strategies that set the foundation for optimal recovery. However, rest beyond 2-3 days following injury may be detrimental to recovery (Silverberg and Iverson 2013) and is no longer recommended in recent guidelines.
2. Low Intensity Cardiovascular Activity
After 2-3 days of rest immediately following injury, it is important to begin low-intensity cardiovascular activity, with the goal of incr
easing the heart rate. This active rehabilitation approach contributes to recovery by reducing symptoms and enhancing neurological recovery, in addition to the many other physical and psychological benefits of physical activity (Leddy et al. 2016). Landmark research from the University of Buffalo shows that patients with concussion who begin low level cardiovascular exercise after the initial 2-3 days of rest recover sooner than those prescribed rest or stretching exercise
s (Leddy et al. 2019; Leddy et al. 2019).
During this stage, symptom monitoring and a gradual increase in intensity are essential to ensure that exercise is performed at an appropriate level to support recovery. The best way to accomplish this is to use the Buffalo Concussion Treadmill Test, which systematically determines the level of exercise that a patient can tolerate before symptoms get worse (Leddy and Willer 2013). The Buffalo treadmill test also assesses the patient’s heart rate response to incremental exercise, which provides useful insight regarding autonomic nervous system function. An alternative approach that is also effective is to begin exercising at 50% of one’s age-predicted maximal heart rate (calculated as follows: HRmax = 220 – your age), which is likely to be tolerated well without worsening symptoms (Micay et al 2018). For both approaches, careful monitoring of HR and symptoms is important to aid the healthcare team in gradually progressing exercise intensity based on the patient’s symptom response.
3. Sport Specific Exercise
Once one is able to tolerate an increased heart rate, the next step is to continue challenging the brain by adding other elements, including balance, coordination, vision, strength, and cognitive demand, in addition to an elevated heart rate. This may involve adding components such as jumping, footwork, or ball control. Many times, even though one is able to achieve a high heart rate during cardiovascular exercise, they may experience difficulties with more complex activity because the brain is challenged to integrate multiple sensory cues. For this reason, it is essential to work closely with the healthcare team to manage this stage of activity most appropriately.
For athletes, independent sport-specific drills are followed by non-contact training with the team. Before returning to practice for non-contact training, one would ideally undergo advanced exertional testing to ensure they are ready for this transition. Exertion testing provides a more objective and thorough evaluation of the individual’s physical and neurological functioning. This involves a cardiovascular assessment that carefully tests the various neuromuscular, vestibular, visual, and cognitive processes that are commonly affected after a concussion and may impact the individual’s ability to safely engage in sport. Often impairments can be detected during an exertion test that otherwise may not be noticed when returning to sport, making this a valuable consideration. After successfully reintegrating with the team, the medical team will decide where to clear the athlete for contact practice and then normal game play.
What about resistance training?
Many people are keen to restart their resistance training regimen (i.e., weightlifting, resistance bands, calisthenics, etc.), however there are reasons to be cautious with this type of activity (Worts et al. 2019):
- Resistance training is by nature a more intense form of exercise. It elicits a strong stress response, activating the sympathetic branch of the autonomic nervous system (i.e., fight or flight response), which already tends to be hyper-active following concussion.
- Sympathetic activation during resistance training elevates stress hormones and increases blood pressure to a greater extend that cardiovascular exercise.
- After a concussion, the autonomic nervous system is often impaired and not able to properly regulate blood flow to the brain in response to these changes, which may produce symptoms such as headache or dizziness.
- Breathing patterns also tend to change during resistance training. Holding one’s breath is often necessary when lifting heavy loads (known as the Valsalva maneuver), which may increase pressure in the head and cause headache.
It is therefore essential to first retrain the autonomic nervous system through progressive cardiovascular activity, as described above.
Thereafter, a careful approach to initiating resistance training is necessary. While there is currently little research on resistance training following concussion, preliminary recommendations suggest a low-intensity circuit style approach targeting a variety of muscle groups (Sullivan et al. 2018). Initially, the level of resistance should be low, around 30-50% of the individual’s 1-repetition max (the most weight one can lift for a single repetition), with a greater focus on maintaining proper form and breathing mechanics throughout 10-15 repetitions. Additionally, the rest period between sets of specific exercises should be at least as long as the time it takes to complete the exercise. With support from the healthcare team, resistance training parameters can be gradually progressed to achieve one’s goals.
Through regular exercise coaching, our team ensures that the individual progresses through these stages at the ideal pace. Although there is a rough guideline, return-to-athletics management is individualized in keeping with the variable nature of concussion and its recovery. Recognizing the unique challenges that each patient experiences, we aim to provide strategies and support to help people incorporate exercise in their rehab plan and achieve the many benefits of an active lifestyle.
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