Can You Exercise After a Concussion?

If you have experienced a concussion, you may wonder when it is safest to exercise after concussion. This type of head injury, also known as mild traumatic brain injury, affects many people in the United States.

The top causes in adults are falls and car accidents, but they also happen frequently in sports — 1.6 million to 3.8 million times a year, according to the Brain Injury Research Institute.

Not everyone with a concussion is "knocked unconscious." Still, even those with minor symptoms need to be careful about returning too early to physical activity, lest they prolong their recovery or put themselves at risk for additional injury.

Read more: If Concussion Symptoms Persist, You May Have Post-Concussion Syndrome

Concussions are diagnosed based on how a person is impacted physically as well as symptoms. The source of injury can be a fall, a blow to the head or a force that causes the body to speed up and slow down rapidly.

With such forces, the brain — which is cushioned by cerebrospinal fluid inside the skull — slides around and can get banged up, which can temporarily change the way brain cells function; however, most of the time the brain's structure isn't affected.

Some people with concussions lose consciousness, but many don't. Immediate symptoms can also include nausea and vomiting, disorientation, confusion or trouble saying the person's name, or trouble remembering new things or what happened right before the concussion. Balance problems can also result, according to Mayo Clinic.

After a concussion, a person might have a variety of other symptoms that begin right afterward or on a delayed basis.

Such symptoms, which can last for months, include headache, blurry vision, sensitivity to light and noise, ringing in the ears, fatigue, trouble concentrating, emotional changes like irritability and depression, anxiety, trouble sleeping or sleeping too much.

The severity of these symptoms and the length of time they last are very important in determining when you can return to exercising.

It is important to be evaluated by a health care provider after every concussion, to be sure a more serious brain injury isn't present. Guidelines are based on expert consensus and not clinical research.

In general, rest and close monitoring is recommended for at least 24 to 48 hours and then until symptoms resolve. Here "rest" refers to avoiding any kind of exercise or strenuous activity and also stress on the brain like doing finances or maintaining the same level of computer screen time at work.

According to an article published in May 2015 in the journal Molecular and Cellular Neuroscience, 80 to 90 percent of people's concussion symptoms resolve in 7 to 10 days, though children, adolescents and older people, as well as people who have had a prior concussion, may take longer.

There is no single test that a health care provider can perform to determine if concussion symptoms have resolved. Difficulty with thinking and attention may be easily missed, so some providers refer people for specialized neuropsychological testing as they decide whether to resume activity.

When it's decided to begin exercising, a graded return to activity may be advised, beginning with light aerobic activity only going up to 70 percent of the maximum heart rate.

After a trial interval, the appropriateness of pursuing more vigorous exercise can be gauged. If symptoms return at any point, people are advised to go back to the last level of exercise not associated with symptoms.

Return to playing contact sports after concussion is a special issue. According to the American Association of Neurosurgeons, the likelihood of suffering a concussion while playing a contact sport is as high as 19 percent per year of play.

Also common are head impacts with no signs or symptoms, called "subconcussions," that may be associated with changes in brain cells and could put some players at risk for worse symptoms from full concussions.

Per NFL guidelines, as reported by the American Association of Neurosurgeons, players with concussions should only be cleared to play once they've had testing that shows their thinking and memory is normal and once their symptoms are resolved.

They also recommend going through steps, from light aerobic activity to sport-specific exercise and drills without head impact, followed by noncontact training drills that are more complex, progressive resistance training, then, after medical clearance, full-contact practice and finally return to play.

Returning to exercise too soon could have a number of negative effects. Aside from the return of concussion symptoms, early return to play may put a person at risk of an additional concussion.

According to an article published in March/April 2013 by Sports Health, 91.7 percent of repeat concussions among college football players occur within 10 days of the first concussion. This may be because of slowed reaction time and other thinking problems that happen with a concussion, which may not be evident without specialized testing.

Rarely a person who sustains a second minor traumatic brain injury will experience something called "second impact syndrome."

This is a controversial disorder — more commonly found in young children — with very few cases known, in which someone with a mild concussion experiences another mild concussion, often immediately after or within weeks and has severe and fatal brain swelling. This disorder is still being studied by researchers.

Read more: The 8 Activities That Have the Most Benefits for Your Brain

If you or a loved one have suffered a concussion, be on the lookout for signs of serious brain injury, including persistent or worsening headache, changes in vision, dizziness, trouble hearing, trouble speaking or slurred speech.

Signs can also include problems with movement, problems with coordination or balance, trouble recognizing people or places, problems with attention or focusing, feeling confused/disoriented, drowsiness/unable to wake up, unusual behavior, worsening irritability, seizures, vomiting or even one pupil larger than the other. Seek emergency medical care if any of these are present.

If you have had a concussion, it's important to protect yourself as much as possible from further concussions. You can do this by always wearing a helmet when engaging in sports and recreational activities and by using a seat belt when riding in a car. And, when possible, choose your activities with your brain's health in mind.