Do you often wake up feeling groggy or sluggish—and still cannot shake the feeling by lunchtime? Is it tough for you to recall details like the date of your next dentist appointment, the name of that actress on the TV screen or what you ate for dinner last night? Is this your first time reading this paragraph or have your eyes already glazed over the text, not fully processing the information?
If you answered yes to any of the above questions, you are not alone. In fact, it is so common, there is even a name for it: brain fog. While brain fog is not an official medical diagnosis, it essentially means feeling confused or mentally disorganized, like a struggle to put ideas into words or think clearly. We all experience this feeling from time to time, and it is also associated with certain changes in the brain.
What Causes Brain Fog
Some conditions related to aging, like menopause, can bring on brain fog, as can neurological or mental health issues like depression or anxiety. In other cases, your brain may feel fuzzy as a result of illness, a change in medication or sleep deprivation. (Who has not felt a little off due to jet lag or while recovering from a cold?) Many individuals who are going through cancer treatment develop brain fog—sometimes called “chemo brain”—and it has been identified as a symptom of COVID-19. Patients who undergo surgery may experience brain fog for days or even weeks after coming out of anesthesia. (The medical term is postoperative cognitive decline.)
The good news is that brain fog is generally temporary but experiencing it can still be frustrating and even unnerving. Some of you may have gone down a Google rabbit hole trying to figure out what is going on inside your head. The truth is that scientists still are not sure exactly what causes this brief lack of mental clarity and inability to focus. Studying brain fog can be difficult because it is not a long-term state, and we do not know precisely what this feeling looks like in terms of brain cell activity. One prevalent theory is that it is related to a disruption in blood flow to the brain. Some research also points to inflammation as a culprit, while other evidence suggests diabetes may contribute to brain fog by way of messing with blood sugar levels.
How Fitness Fights Brain Fog
While we still may be working out the mechanism, we do know that exercise can help you feel sharper. Getting your heart pumping increases the flow of oxygen-rich blood throughout your body, including the brain, which boosts brain cell performance. Exercise also has anti-inflammatory benefits and increases levels of brain-derived neurotrophic factor (BDNF), a molecule that helps promote the growth of new brain cells and keeps existing neurons in tip-top shape.
While there are not a lot of studies that have been done on brain fog in general, research published earlier this year provides evidence that exercise can help protect against so-called “chemo brain.” The study found that women with breast cancer who were most active before, during and after chemotherapy treatment were the least likely to develop issues with memory and cognition.
The Best Type of Exercise to Keep Your Brain Sharp
Instead of gentle activity, aim for higher-intensity exercise to get your heart rate up to at least 60 percent of your age-appropriate maximum. (Important note: If you are experiencing brain fog and also have a medical condition, talk to your doctor to determine what type of exercise routine is safe and manageable.)
To see sustained benefits, consistency is key. That means doing some activity every single day, but it does not always have to be at the same level of intensity—and you certainly do not have to do the same workout.
High-intensity interval training, or HIIT—a workout that alternates between spurts of hard-charging, intense activity, and periods of less strenuous activity—is a good choice two or three times a week. On other days, you can opt for what I call “active recovery,” or moderate activity, like yoga or a low-impact Bike ride, which gets you up and moving without pushing your body too hard.
As for the best time to exercise, mornings seem to have an advantage. There’s some data indicating that exercising in the evening may disrupt your sleep, and a poor night’s rest certainly can contribute to more brain fog. Getting a jump-start first thing in the a.m. may also be better because you may experience enhanced mental sharpness throughout the day. Bonus: Thanks to that rush of exercise-induced endorphins, you will also start your day with a brighter outlook—which is so much better than waking up feeling groggy and grumpy.
Jay Alberts, PhD is a Cleveland Clinic scientist and paid consultant of the Peloton Health and Wellness Advisory Council. His research is aimed at understanding the structure-function relationships within the central nervous system and evaluating the impact of behavioral and surgical interventions to improve motor and non-motor function in Parkinson’s disease, stroke, Alzheimer’s and other neurological populations. Dr. Alberts is currently leading two multi-site clinical trials investigating the role of exercise in slowing the progression of Parkinson’s disease.
This content is for informational and educational purposes only and does not constitute individualized advice. It is not intended to replace professional medical evaluation, diagnosis, or treatment. Seek the advice of your physician for questions you may have regarding your health or a medical condition. If you are having a medical emergency, call your physician or 911 immediately.