Recovery

When Endurance Athletes get Concussions

Why Invisible Injuries Demand Visible Care.

By Uphill Athlete

September 17, 2026

By Dr. Eliza Sampey, DPT

Endurance athletes are comfortable with discomfort. We train ourselves to distinguish pain from danger, fatigue from failure, and inconvenience from true risk. That skill serves us well in the mountains, until it doesn’t.

Brain injuries do not behave like other injuries we are accustomed to managing. A concussion does not always announce itself with dramatic symptoms. There may be no blood, no obvious trauma, no moment that clearly signals, “This is serious.” And yet the cost of misjudging a brain injury can be measured not in days or weeks, but in months, years, or the permanent reshaping of how an athlete experiences their body and mind.

If you trail run, ski, mountain bike, climb, or move fast through complex terrain, concussion is part of your risk landscape whether you acknowledge it or not. You may never experience one yourself, but you will almost certainly be near one. Understanding how concussions actually work—and how they should be managed—is fundamental knowledge for mountain athletes and the partners who support them.

Most concussions in endurance athletes occur in the backcountry. That context matters. When you are remote, stopping is rarely simple. Evacuation may not be immediate. Often the only option is to keep moving, even after a significant crash. Layer on the fact that concussion is an invisible injury—hidden inside the skull—and it becomes easy to rationalize continuing on. Add endurance culture’s deep familiarity with pushing through pain, and you have the perfect conditions for minimizing a serious injury.

Immediately after a fall or collision, adrenaline almost always masks symptoms. This is why one of the most important early interventions is also the simplest: pause. Sit down. Breathe. Give the nervous system ten to fifteen minutes to settle before deciding whether you are “fine.” Many concussion symptoms emerge only after adrenaline fades.

Early symptoms vary widely. Some athletes notice headache or a sense of pressure in the head. Others feel dizzy, lightheaded, or vaguely “off.” Extreme fatigue is common, often appearing after the athlete has already resumed activity. Light or sound sensitivity, irritability, clumsiness, balance issues, and nausea are also frequent. Cognitive symptoms—confusion, difficulty concentrating, or short-term memory disruption—may be subtle or transient. Emotional changes, particularly irritability, are often overlooked but highly relevant.

Two misconceptions deserve particular emphasis. First, you do not need to hit your head to sustain a concussion. A sufficiently forceful body blow that whips the head can cause the same injury. Second, loss of consciousness is uncommon; fewer than ten percent of concussions involve it. Waiting for these signs means waiting too long.

To understand why concussion is so disruptive, it helps to understand what is actually happening in the brain. Concussion is no longer thought of primarily as the brain “slamming into the skull.” Instead, it is best understood as a stretch injury to brain cells. When the head or body experiences rapid acceleration or deceleration, the brain deforms within the skull. Billions of nerve cells stretch simultaneously.

Each nerve cell contains a long body, called an axon, lined with ion channels that regulate the flow of neurochemicals. Under normal conditions, these channels open and close selectively. After concussion, they are forced open all at once. Neurochemicals and ions move where they should not. Blood flow to the brain becomes dysregulated. Inflammation increases. The brain enters what we call a neurometabolic energy crisis.

Callout Box: Red Flags — Seek Immediate Emergency Care

These signs warrant immediate evacuation or emergency evaluation:

Worsening neck pain or cervical spine tenderness
Seizures or convulsions
Persistent double vision
Loss of consciousness lasting more than a few minutes
Weakness, numbness, or tingling in limbs
Repeated or uncontrollable vomiting
Severe or worsening headache
Increasing confusion, agitation, or combativeness
Visible skull deformity (not just a “goose egg”)

In the first twenty-four to forty-eight hours, the brain struggles to produce energy efficiently. Over the next three to six weeks, normal metabolic pathways slowly restore themselves. This timeline is critical, and it is independent of how severe the concussion appears at first. Symptoms may resolve in a week or two, but metabolic recovery continues long after symptoms fade. There is no reliable way to know whether an individual will recover in three weeks or six. For that reason, the most conservative—and safest—assumption is to behave as though it will take six weeks for your brain to recover.

This prolonged recovery window explains why the brain is particularly vulnerable to re-injury during this time Before concussion, the brain operates at its normal baseline of energy availability, blood flow, and regulatory control. A concussion drops that baseline significantly. Recovery is not instantaneous; it is a gradual climb back toward normal. A second head injury before baseline is restored compounds the deficit. In rare cases, this can lead to catastrophic outcomes such as second impact syndrome. Far more commonly, it results in prolonged physiologic and metabolic recovery that stretches weeks into months.

This is why one of the strongest predictors of long-term problems after concussion is not the initial injury itself, but whether a second injury occurs during the vulnerable window. Pushing to return to high intensity and/or long duration exercise during this critical 3-6 week period will also lead to long-term problems. Your brain is in an energy crisis, and if you force it to output more than it has the capacity for while it’s trying to heal, the impacts are significant.

The first forty-eight hours after concussion should be treated with respect, not fear. Current best practice recommends relative rest, not complete inactivity. Relative rest means avoiding activities that worsen symptoms while allowing light, symptom-neutral movement. Short walks are acceptable if they do not provoke symptoms. Cognitive and emotional load matter just as much as physical exertion. Work, screens, emotionally taxing conversations, and decision-making all require brain energy.

Sleep is not only allowed; it is encouraged. The outdated belief that a concussed person should not sleep has been thoroughly debunked. After an initial 4-6 hour monitoring period for red flags, sleep is one of the brain’s most powerful recovery tools. Screen time, however, should be significantly reduced in the first forty-eight hours, as excessive early screen exposure has been shown to prolong symptoms. Alcohol, caffeine, and highly processed or sugary foods should be avoided during this period and ideally limited throughout the first six weeks of recovery.

After the initial rest period, recovery should not stall. Prolonged inactivity is no longer recommended. The most important rehabilitation intervention after forty-eight hours is low-intensity, steady-state exercise performed below symptom threshold. This supports cerebral blood flow regulation, reduces inflammation, and helps restore metabolic balance. For endurance athletes, this can feel counterintuitive. Heart-rate zones used for training do not apply here. Exercise intensity must remain below the level that provokes symptoms, even if that feels unusually easy.

Concussion is not a single-system injury. It disrupts multiple interconnected systems, including the autonomic nervous system, metabolic system, visual processing, vestibular function, cervical spine mechanics and proprioception, cognition, and emotional regulation. Headache, often labeled as a concussion subtype, is better understood as a symptom that can arise from any of these systems.

Because of this complexity, siloed care often fails. Treating only the neck, or only the vestibular system, or only addressing the brain’s ability to process vision rarely resolves the full picture. Effective rehabilitation identifies which systems are impaired, addresses them individually but concurrently, and then reintegrates them progressively. This approach is especially important for endurance athletes, whose brains and bodies are exceptionally good at compensating. Compensation can mask deficits for months or even years, only to resurface under renewed training or life stress.

This is why the quality of concussion management matters more than the number of concussions sustained. Poorly rehabilitated injuries leave vulnerabilities beneath the surface. Well-managed concussions normally achieve full resolution of related system dysfunctions within a few months or less

The most important takeaway for mountain athletes is simple but not easy: take concussion seriously. Treat it as the brain injury it is. Resist the urge to test it with intensity. Seek care from rehab providers who understand concussion in endurance athletes – this will usually be a physical therapist or chiropractor who specializes in concussion recovery. Support partners not by pushing them back into activity, but by helping them rest, recover, and rebuild intelligently.

Your brain is not replaceable. In the mountains, we pride ourselves on judgment. Managing concussion well is one of the clearest expressions of that skill.

A One-Page “Good Patient” Checklist

Don’t

Hit your head again in the first six weeks
Test recovery with hard workouts
Isolate in a dark room
Return to normal training too soon – a return should be slow, progressive, and supported by rehab.

Take the first 48 hours seriously and let your brain rest
Sleep as much as needed after the initial 4-6 hour watch period
Begin sub-symptom steady state exercise after 48 hours (start with 20 minutes duration)
Track symptoms, sleep, mood, and energy
Seek a concussion-literate provider within the first week