A concussion is a mild traumatic brain injury that results from a blow to the head or body, causing the brain to move rapidly within the skull. This forceful movement temporarily disrupts normal brain function, leading to a complex array of symptoms such as headaches, dizziness, and difficulty with concentration. Because the brain is in a state of physiological vulnerability following the injury, the immediate and non-negotiable rule is that exercise and vigorous activity must be restricted. A safe return to exercise is not a matter of simply “feeling better” but requires a gradual, step-by-step reintroduction of activity under direct medical supervision.
Immediate Post-Concussion Activity Restrictions
Following a concussion, the brain experiences a period of metabolic crisis where energy demands and blood flow regulation are mismatched. This initial phase necessitates physical and cognitive rest, traditionally recommended for the first 24 to 48 hours. This short-term rest allows the brain to begin recovering from the complex neuronal and ionic changes caused by the trauma.
All activities that elevate heart rate or blood pressure must be avoided. This includes high-intensity cardio, heavy weightlifting, and activities involving jarring head movements like running or jumping. Cognitive rest is equally important, meaning excessive screen time, intense studying, or heavy concentration tasks should be minimized to preserve the brain’s limited energy resources.
The most severe danger of returning to activity too soon is Second Impact Syndrome. This rare condition occurs when an individual sustains a second head injury before the brain has fully healed from the first, which can trigger rapid and uncontrollable brain swelling and prolonged recovery.
Establishing Baseline and Medical Clearance
The transition to an exercise program is determined by the resolution of symptoms at rest, not by a specific number of days. Before any physical exertion can be attempted, the individual must complete a full day of normal, non-strenuous activities, such as school or work, without the re-emergence of any concussion symptoms. This establishes a symptom-free baseline.
The decision to begin the Return-to-Exercise protocol must be made by a healthcare professional experienced in concussion management. Post-concussion symptoms like exercise intolerance often result from physiological dysregulation that requires professional assessment. A medical professional will evaluate factors like balance, cognitive function, and neck stability to ensure the brain physiology is stable enough to tolerate exertion.
Medical clearance is required, particularly for athletes, before progressing to any activity that carries a risk of re-injury or contact. The professional provides written clearance to initiate a structured, individualized protocol. This ensures the gradual return is tailored to the specific nature and severity of the injury.
The Graduated Return-to-Exercise Protocol
The Graduated Return-to-Exercise (GRET) protocol is a standardized, step-wise approach designed to safely reintroduce physical activity by gradually increasing intensity and complexity. The protocol typically consists of five or six distinct stages. The individual only advances to the next stage after completing the current stage symptom-free for a full 24 hours. This progression is designed specifically to challenge the cardiovascular and neurological systems without inducing symptom flare-ups.
Light Aerobic Exercise
This first step focuses purely on increasing the heart rate without resistance or jarring movements. Activities include walking, swimming, or stationary cycling, keeping the intensity below 70% of the maximum predicted heart rate for 10 to 20 minutes. This gently re-establishes the brain’s tolerance for exercise and promotes improved cerebral blood flow.
Sport-Specific Exercise
This stage introduces movement patterns relevant to the individual’s sport or regular activity, but without any head impact. Examples include moderate running, light agility drills, or skating, with intensity elevated to between 40-60% of maximum exertion. This increases the cardiovascular load while adding dynamic movement and coordination.
Non-Contact Training Drills
This step incorporates more vigorous resistance training and complex agility. Activities may include full-speed sprinting, cone drills, and full-weight training, increasing the exertion level to 60-80% of maximum. The goal is to restore confidence and assess functional skills, including reaction time and directional change, under high-intensity physical stress.
Full Contact Practice and Return to Play
The final steps are Full Contact Practice and Return to Play or Competition. The full contact stage allows participation in normal training activities to ensure the individual can handle the physical demands and potential minor impacts of their sport without symptoms. Only after successfully completing all stages and receiving final medical clearance can the individual return to full competition.
Monitoring Symptoms and Stopping Criteria
A successful return to exercise hinges on monitoring for any return or worsening of concussion-related symptoms during or after an activity. Common indicators that an activity is too strenuous include a flare-up of headache, increased dizziness or nausea, or heightened sensitivity to light or noise. These symptoms signal that the brain is being physiologically overloaded and requires a reduction in activity.
If symptoms worsen significantly during a GRET stage, the activity must be stopped immediately. Any symptom exacerbation should be mild and brief, ideally resolving within an hour of stopping the activity. If symptoms increase beyond a mild level or persist for more than one hour, the individual should not attempt that level of activity the following day.
Following a persistent symptom flare-up, the individual must retreat to the previous stage of the protocol that was successfully completed without symptoms. Reverting to a previously tolerated level allows the brain to stabilize before attempting the progression again, ensuring the recovery process remains safe and symptom-limited.