A concussion is a mild traumatic brain injury (mTBI) resulting from a jolt or blow to the head or body that transmits an impulsive force to the brain. This causes a temporary disturbance in brain activity, leading to symptoms like headaches, dizziness, or confusion. While rest is necessary for initial recovery, the historical advice of complete “cocooning” is no longer recommended. Modern guidelines emphasize a structured, gradual return to physical and cognitive activity, guided by symptoms, to potentially speed up recovery.
The Necessity of Initial Rest
The first 24 to 48 hours following a concussion are reserved for relative rest to allow the brain to stabilize. This period is necessary to mitigate the initial neurometabolic cascade triggered by the injury. Physical rest means avoiding strenuous activity, heavy lifting, or anything that significantly increases the heart rate. Walking that does not worsen symptoms is acceptable, but jogging or resistance training is not.
Cognitive rest is equally important during this initial phase, requiring a limitation on mentally demanding tasks. Activities like intense studying, complex problem-solving, or excessive screen time should be reduced. The goal is to minimize symptom provocation, such as headache or cognitive fogginess, which can delay the start of rehabilitation. Prolonged, strict rest beyond two days can be detrimental, potentially leading to anxiety, depression, and a longer recovery time.
Graduated Return to Activity Protocol
The return to physical activity should begin as soon as the initial 24 to 48 hours of relative rest are complete, provided symptoms are tolerable and stable. Medical professionals use a structured, step-by-step protocol (often 5 or 6 stages) to guide a safe increase in exertion. A fundamental rule is that a person must spend a minimum of 24 hours in each stage without significant worsening of symptoms before progressing. If symptoms return, the person must drop back to the previous symptom-free stage and rest for 24 hours before attempting to progress again.
The first stage involves light aerobic exercise, such as brisk walking, stationary cycling, or light swimming, keeping the heart rate below 70% of the predicted maximum. The goal is to increase heart rate and cerebral blood flow without resistance training or head movement that provokes symptoms. If successful, the second stage introduces moderate aerobic exercise, such as light jogging or increased resistance on a stationary bike. This level aims to increase the duration and intensity of exercise while still avoiding any activity with a risk of head impact.
The third stage involves non-contact, heavy exertion, including complex movement patterns like sport-specific drills, running, or full-body weight training. This phase focuses on adding movement, coordination, and increased thinking demands to the activity. The final stages, typically four and five for athletes, involve a transition to full practice with contact (after medical clearance) and finally, full return to game competition. For non-athletes, the protocol usually concludes once they can tolerate full-intensity, non-contact exercise without symptoms.
Monitoring Symptoms During Activity
The progression through the return-to-activity protocol is guided by continuous monitoring of symptoms. The person must be highly attuned to any physical or cognitive changes during the activity and in the hours immediately following it. A significant increase in the severity of a symptom, or the return of multiple symptoms, signals that the brain is being overtaxed.
Key physical symptoms that require stopping or scaling back include escalating headache intensity, new or increased dizziness, or the onset of nausea. Cognitive symptoms like “brain fog,” trouble concentrating, or increased light or noise sensitivity indicate that the activity level is too high. If symptoms worsen and the change is sustained for more than an hour after stopping, revert to the previous symptom-free level.
Risks of Premature Physical Activity
Ignoring the symptom-guided protocol and returning to physical activity too soon risks prolonging recovery. Pushing through worsening symptoms can delay recovery and significantly increase the chance of developing Post-Concussion Syndrome (PCS). PCS is characterized by persistent symptoms that can last for months or even years, often requiring specialized treatment. Forcing the brain to exert itself before it is neurologically ready can lead to a prolonged state of poor blood flow regulation and autonomic nervous system dysfunction, which is central to PCS.
A rarer but dangerous complication of premature return is Second Impact Syndrome (SIS), which occurs when a person sustains a second head injury before the first one has completely healed. This second, often minor, blow can cause rapid brain swelling, leading to severe disability or death. Because the brain is in a vulnerable metabolic state after the initial injury, avoiding any activity with a risk of re-injury, such as contact sports, is necessary until a medical professional has given full clearance.