A concussion is a traumatic brain injury from a bump, blow, or jolt to the head, or a forceful body impact that moves the head rapidly. This movement damages brain cells, leading to temporary changes in brain function. After a concussion, physical and cognitive rest is important for the brain to heal.
Immediate Worsening of Symptoms
Exercising with a concussion can immediately worsen existing symptoms. Individuals may notice an intensification of headaches, increased dizziness, and nausea. Sensitivity to light and sound often heightens, and overwhelming fatigue can set in. Cognitive difficulties, such as trouble concentrating or memory issues, also tend to become more pronounced. This exacerbation occurs because exercise naturally increases blood flow and metabolic demand within the brain. A concussed brain is already working to recover from injury, and its ability to regulate cerebral blood flow can be compromised. This dysregulation means the brain may struggle to manage the increased demands, potentially leading to erratic blood flow or elevated intracranial pressure. Such physiological responses can trigger or intensify symptoms, signaling the brain is overtaxed.
Prolonged Recovery and Persistent Issues
Engaging in physical exertion prematurely can significantly prolong concussion recovery, causing symptoms to persist longer. Pushing the brain too soon hinders its ability to heal and rebalance its metabolic functions. This can delay the resolution of symptoms and extend the time before a full return to daily activities is possible. Exercising too early also increases the risk of developing Post-Concussion Syndrome (PCS), a condition where concussion symptoms continue for weeks, months, or even longer. While current research suggests that complete rest beyond 48-72 hours can sometimes delay recovery, overexertion or ignoring symptoms can contribute to chronic issues. The brain requires adequate time and a managed return to activity to restore its functions and prevent long-term complications.
Understanding Second Impact Syndrome
Second Impact Syndrome (SIS) is a rare but serious condition occurring if a second concussion is sustained before full recovery from an initial head injury, as the brain is vulnerable and even a minor second impact can trigger catastrophic events. This second blow does not need to be severe and can happen minutes, days, or weeks after the first concussion. When SIS occurs, the brain experiences rapid and severe swelling, known as diffuse cerebral edema. This swelling results from the brain’s arterioles losing their ability to regulate blood flow, leading to a massive increase in blood and brain volume within the skull. The rapid increase in intracranial pressure can cause brain herniation and neurological deterioration, leading to death or permanent, severe disability within minutes. Exercising with an unrecovered concussion raises vulnerability to such an event if another head impact occurs.
Safe Return to Physical Activity
A safe return to physical activity after a concussion requires a gradual, step-wise progression, always under healthcare professional guidance. Initial recovery involves 24 to 48 hours of relative rest for acute symptoms to subside. Then, light activity like walking or stationary cycling can be introduced, monitoring for symptom return. Progression involves slowly increasing intensity, duration, and complexity, from light aerobic exercise to sport-specific drills, non-contact training, and finally full contact, if applicable to the activity. Advance only if no new symptoms appear, stopping immediately if symptoms reappear, and obtain medical clearance before returning to higher-risk activities.