A concussion, medically known as a mild traumatic brain injury (mTBI), is a functional disturbance of the brain caused by a bump, blow, or jolt to the head or body. This sudden force causes the brain to move rapidly within the skull, creating chemical and metabolic changes that temporarily affect function. Symptoms can include headaches, dizziness, difficulty concentrating, and balance problems. Historically, medical advice for recovery was strict physical and cognitive rest until all symptoms resolved. Modern consensus, however, favors a supervised, controlled approach that incorporates exercise to promote healing.
The Shift to Active Recovery
Strict, prolonged rest, often called “cocoon therapy,” is now considered outdated and potentially counterproductive to recovery. Extended periods of inactivity lead to negative effects that hinder the brain’s healing process. These consequences include physical deconditioning, which lowers the body’s tolerance for activity, and psychological distress such as anxiety, depression, and social isolation.
Research indicates that controlled physical activity helps normalize physiological dysfunction in the injured brain. A concussion can disrupt the brain’s ability to regulate its own blood flow, known as cerebral autoregulation, causing symptoms like exercise intolerance. Aerobic exercise performed at the correct intensity can restore this regulatory system, ensuring the brain receives the necessary oxygen and glucose for repair. This controlled activity helps reduce symptom persistence, leading to a faster return to daily life for many patients.
Timing and Initiation of Exercise
Timing the initiation of exercise is a crucial aspect of current concussion management. The initial period following injury, typically the first 24 to 48 hours, should involve “relative rest,” not strict bed rest. During this acute phase, light activities of daily living, such as walking around the house, are permitted as long as they do not significantly worsen symptoms.
Beyond the initial 48 hours, the focus shifts to initiating graded physical activity, provided the patient is medically cleared and symptoms have stabilized. Introducing light aerobic exercise within the first week is associated with a significantly lower risk of developing persistent post-concussion symptoms. Delaying exercise initiation beyond the first week may make the recovery trajectory less favorable.
Activity initiation is driven by individual tolerance, not a fixed date on a calendar. The goal is symptom-limited activity, meaning a person should stop or reduce the activity if symptoms increase beyond a mild, tolerable level. This approach ensures the brain is gently stimulated without being over-exerted during the subacute recovery phase.
Graded Exercise Protocols
Once medically cleared, structured exercise involves a highly individualized, step-by-step increase in activity guided by a specific protocol. The core principle is the sub-symptom threshold approach, meaning exercise intensity must not provoke a significant increase in concussion symptoms. This controlled exertion maximizes the therapeutic benefits of exercise.
A common method to determine this safe heart rate zone is the Buffalo Concussion Treadmill Test (BCTT) or a similar graded exercise test. During the BCTT, a patient walks on a treadmill with increasing incline or speed until their concussion symptoms are exacerbated. The heart rate achieved just before this exacerbation point is then used to prescribe a safe exercise target, typically 80% of that measured heart rate.
For home-based recovery, low-impact aerobic activities are recommended to maintain a steady, sub-symptom heart rate. Examples include stationary cycling, brisk walking, or using an elliptical machine. The prescribed exercise is usually performed for 20 to 30 minutes, five to six days a week, and intensity is gradually increased only as the patient’s symptom tolerance improves.
Warning Signs and Stopping Criteria
While exercise is beneficial, patients must recognize signs indicating the activity is too strenuous or causing physiological overload. Patients should monitor symptoms closely during and immediately after any exercise session. The general rule for stopping is if symptoms increase by more than two points on a 10-point scale.
Specific warning signs include a severe or rapidly worsening headache, persistent nausea, or prolonged dizziness and balance issues that do not quickly resolve upon stopping. Any exercise causing confusion, visual changes, or vomiting requires immediate cessation. If symptoms are significantly worse or new symptoms appear the day after a session, the previous day’s intensity was likely too high and must be reduced. Communication with a trained healthcare provider is necessary if symptoms are consistently worsened by exercise or linger for an extended period.