
Strenuous race efforts that leave you cross-eyed may make it hard to think straight, but you can prevent it from going any further than that by being mindful.
Overheard during your national news broadcast or read in the headlines of your local paper, recently, the term “Brain Fog” has become popularly used to describe the covid-19 severe symptom of mental fuzziness. However, feeling mentally exhausted or unable to concentrate is not restricted to those who suffer from covid-19. In fact, it is a state that everyone has likely experienced at some point.
“Brain Fog” is clearly a nebulous term, for as much as a phrase can be concise in its ambiguity, meaning that it’s not a clinical term, and therefore not something diagnosable.
But just because it’s hard to define and can differ from person to person doesn’t mean it’s not valid. Nor does it mean that a healthy athlete can’t suffer from its symptoms.

Subjective Memory Impairment (SMI), as it’s sometimes clinically referred to, can happen at any age. A UCLA study found 14% of young adults between the ages of 18-39 and 21% of adults between the ages 40-59 reported instances of SMI, feeling a decline in both memory and cognitive thinking.
What is Brain Fog?
It is not a specific medical condition but rather a symptom caused by an underlying medical or lifestyle issue. It can be characterized by:
- Feelings of Confusion or Poor Mental Clarity
- Lack of Focus or Concentration
- Forgetfulness
- Impaired Decision Making or Disorganized Thinking
- Moodiness
- Drowsiness or Fatigue
- Mental Exhaustion and Feeling “Checked Out”
- Difficulty Communicating or Finding Appropriate Words

Sound familiar?
During a brief period of clarity, it occurred to me I heard the words “Brain Fog” before, but when and in what context escaped me at the moment. Then it came to me. I had listened to my teammate shout it through Discord into my right earbud during our last bike race.
Perhaps it wasn’t significant enough to remember because I had heard it during races so many times before.
Have you ever wondered what may be causing the clouding of consciousness, which occurs when the race gets hard, and you just can’t think straight?
A 2017 study published in the Journal of Applied Physiology connected exercise intensity and oxygen availability. The authors suggested that the oxygen supply does not meet demand at higher exercise intensity and may limit muscle contraction and induce fatigue. In addition, the simultaneous inadequate oxygen delivery to the brain restricts exercise by impairment of central processing.

In a 2017 study published in Neuroscience and Behavioral Reviews, the authors determined that hypoxia (low oxygen level in your blood) harms cognition.
The authors of a 2017 study in Scientific Reports determined that acute exercise improved cognitive ability due to optimal arousal of the brain. However, under conditions of hypoxia caused by intense exercise, the individuals experienced attenuated (minor) improvement.
In short, there may be a scientific explanation for the poor decisions we make during races when the winning move goes up the road without us, or as an ill-timed attack leaves you shot off the back when you are ‘low in air.’ But, if nothing else, it does provide another excuse to add to the list.
Common Lifestyle Causes of Brain Fog
- Inadequate Sleep - When you don’t get enough sleep, it affects your brain in a host of ways. Caffeine consumption can play a role.
- Week Diet - Deficiencies in specific vital components of healthy eating and not consuming enough calories to meet your energy demands are factors.
- Dehydration - Inadequate consumption of fluids is a crucial factor, especially in athletes.
- Stress - When all of your mental energy is devoted to stressors and anxiety, you will be unable to focus on anything else.
- Too Much Multitasking - Thinking or doing several things at once may seem efficient, but it may also affect the ability to think clearly.
- Underlying Medical Conditions and Health Issues or Treatments - Underactive thyroid, Multiple Sclerosis, Chronic Fatigue Syndrome, Fibromyalgia, Hormonal changes (Menopause), and certain medications may be causes. Consult your medical provider immediately if you suspect your ability to think is due to these serious issues.

Burnout or Overtraining is a Key Cause of Brain Fog in Virtual Cyclists
Although it is difficult for the highly motivated athlete to tell the difference between fatigue and burnout, the following symptoms can help you figure it out.
- You are not able to recover during or between workouts in the usual amount of time.
- Your perceived effort makes even light training days seem harder than they should be.
- Training has become a dreadful burden that feels like it is controlling your life rather than being a source of enjoyment.
- You have an abnormal appetite for salty and sweet foods, even on light training days, and you feel that you may be stress-eating more often.
- Your interpersonal relationships are suffering.
- Your body ‘just doesn’t seem right’ for longer than usual without any apparent cause.
- You have insomnia or cannot relax your body and brain when it is time to rest.
Conclusion: Cycling Can Grow Your Brain
When we ride, the blood that flows to our muscles increases, supplying them with more oxygen, and the same process occurs in our brains. As a result, riding improves our ability to think, except in extreme cases when exercise intensity creates the hypoxic condition described earlier. Despite this, the increased state of arousal counteracts this in many cases.
Protein production vital to brain cell formation dramatically increases when biking regularly, as does the ability of the brain’s cells to communicate through an increase in neurotransmitter activity.
These changes counteract the natural decline in brain function and development as we age and may help keep us sharp as we get older.
Perhaps of the greatest significance, cycling has a tremendous effect on psychological well-being. Regular cycling can improve your self-perception resulting in higher self-esteem, improve your mood, reduce anxiety, and allow you to handle stress more efficiently.
Serotonin and dopamine, two of the body’s feel-good chemicals produced while cycling, may be the reason. Or the improved ability to regulate hormones like cortisol and adrenaline may be to credit.
The takeaway here, the benefits of cycling far outweigh the disadvantages, and if you put your mind to it, your Brain Fog will lift and clear the cobwebs of your mental atmosphere.
Except, perhaps, during those critical points during races when we need our brains almost as much as our legs and lungs. Then you are on your own. But, at least you will have a good excuse!
Semi-retired as owner and director of his private Orthopedic Physical Therapy practice after over 20 years, Chris is blessed with the freedom to pursue his passion for virtual cycling and writing. On a continual quest to give back to his bike for all the rewarding experiences and relationships it has provided him, he created a non-profit. Chris is committed to helping others with his bike through its work and the pages of his site.
In the summer of 2022, he rode 3,900 miles from San Francisco to New York to support the charity he founded, TheDIRTDadFund. His “Gain Cave” resides on the North Fork of Long Island, where he lives with his beautiful wife and is proud of his two independent children.
You will read him promoting his passion on the pages of Cycling Weekly, Cycling News, road.cc, Zwift Insider, Endurance.biz, and Bicycling. Chris is co-host of The Virtual Velo Podcast, too!