Can Exercise Affect Our Immunity and Increase the Risk of Illness? The Experts and a Cycling MD Weigh In

A recent study explores this question, and according to the experts and a cycling doc I asked, the prescription might be a bit common sense, and a lot of this makes sense.

Our health and how we feel is foremost on our minds, as it should be. We are athletes after all, and we take our health and fitness seriously. Since the pandemic, the topic of safeguarding our well-being and the strength of our immune systems has gone to the next level. It feels like every article headline and television news broadcast features a health-related fact or story.  


It’s impossible to ignore that our susceptibility to contagious disease is a storyline that may forever pervade our social consciousness. It has gotten to the point where each breath we take comes with a mental checklist of ways we can defend against what lurks within.

woman doing bicep curls

Exercise is at the Top of the Germ Fighting List

On the top of that list for us, exercise and all of the great things that come with it. Athletes take pride in their resolve and believe that payback for our time spent on the bike or in the gym is less time dealing with illness. You may take a deep breath without shame because recent research says it’s true, in most cases.


The goal of this 2020 review debate article published in the Association for the Advancement of Sports Medicine was to bring together a group of experts and ask, “Can exercise affect immune function to increase susceptibility to infection?” The question is simple, and I, for one, would like to know the answer finally.  


As elite eracer and The ZOM contributor Dr. Jacqueline Godbe pointed out in her recent post answering a similar question, it’s not as simple as we think. The experts agreed that regular bouts of short-lasting (up to 45 minutes) moderate to vigorous exercise are beneficial to normal immune system function.  

The Study Brought Together Experts to Debate the Question

According to the researchers, exercise-induced transfer of immune cells from blood to tissues enhances immune function, improves overall health, and decreases disease risk. The news is comforting for the general population of exercisers that fall into this category.


Unfortunately, not all cyclists fit this description. Certainly not me or the cyclists I know. We prefer to subscribe to the mindset that if some exercise shields us from the common cold, then the amount of riding I do is like wearing Superman’s cape.


Much to our dismay, the researchers agree that overdoing it is the equivalent of immunity-cracking kryptonite for high-performance athletes. Illness is second only to injury for training and competition days lost for these athletes. There is ample clinical and laboratory proof substantiating exercise-related immune disturbance and increased susceptibility.

image of woman coughing out virus particles

High-Performance Athletes Are Sick More Often

Here, the disagreement between the experts on this topic gets heated. The lack of laboratory-controlled studies leaves too much room for interpretation. The statistical analysis of incidence shows that high-performance athletes are sick more often, but it doesn’t tell why.


Participation in high-performance events and everything they encompass may be the culprit and not exercise at all. The multiple common aspects that stress our immune systems are all around us and continually challenge athletes. They include life events, exposure, self-care, sleep hygiene, travel, anxiety, mental and physical fatigue, nutrition, among many more.


With all of these factors that directly and indirectly alter immunity and infection susceptibility, it is narrow minded to focus solely on the exercise component. Athletes must learn and head the same lesson.

Exercise Isn’t a Cure-All and it Isn’t All Bad Either

Cycling and other forms of exercise are not a cure-all elixir that creates an impenetrable barrier to microscopic invaders. Don’t waste your time here, Mr. pathogen. You’ll have an easier time with the lazy guy next door.


Our seemingly less motivated neighbor may have it right. If he exercises in moderation and takes the time to look after his nutrition, sleep, and stress, his body may be weaker, but his immune system is not. That doesn’t mean that we should stop riding as much or as hard. I’m not going to.


It means that we need to work on recovery and employ sensible training as much as we do burying ourselves in the hurt locker. I have heard this mantra before, and the context is varied and fits so many cycling scenarios. Recovery is as essential as training, and the best ability is availability. 

Common Sense and Sensible Training Are the Best Medicine

We’ve all heard it before. Listening is the hard part, even when it all seems like common sense to outsiders looking in. For instance, the following is a list of things to do and not do if you want to be at your available best.

Picture of person washing their hands

Be sure that the air in your indoor cycling space is clean, circulated, and free of harmful particles and toxins often found in basements and concealed areas, as explained in this recent ZOM article on the subject.

Reset Your Expectations When You’re Sick

If you happen to come down with something, take the opportunity to be realistic in your expectations. You don’t have to surrender your goals, but you should be flexible and resist the anxiety of lost training days.  


Chances are, if you back it down a notch for a few days, you won’t sacrifice much fitness. However, you risk exacerbating the issue and prolonging your recovery by hitting it too hard too soon. It is better to be slightly undertrained when keeping your eye on the big picture and future goals.    

You Won’t Win the Race But You Could Lose It

You won’t win the race against illness by trying to tough it out in the short term. You can lose it if you don’t listen to your body, and you can’t outride your runny nose, and it becomes something worse.


What’s worse for the cyclist? Out-of-control illness forces us to spend prolonged time on the couch that we should enjoy in the saddle because we are our worst patients. No cyclist has time for that!  

Above the Neck Ride, Below Rest—Uh, Not Exactly

Oh yeah. How about the old cycling adage, “Above the neck ride, below the neck rest?” I asked Neurological ear specialist and competitive cyclist Marc Eisen, MD Ph.D., and this is what he had to say. 

“We may have heard this about training when ill, “Above the neck ride, below the neck rest.”  It draws a line in the sand between head cold symptoms (congestion, sore throat, runny nose) and lung involvement (fevers, cough, aches). But it oversimplifies illness, and while it may be a good general rule of thumb, we can do better.


We have our bodies to listen to and metrics like heart rate and power that indicate our bodies’ training ability. Take that as a sign that your body should take a rest. But there is more to consider.


We ride to achieve multiple things. Such as benefits to our bodies and minds for short-term and long-term gains. Our bodies and our minds become accustomed to our workouts.  


During illness, our bodies may not let us ride hard, even if our heads would allow it.  When our bodies fight illness, they require the rest they need to recover. But our brain still craves the trainer’s drone, the focus, and the break from the distractions that bombard us during the remainder of the day.  


Why not achieve both? Rest for the body and benefit for the mind — avoid any real efforts on the bike but take the time to put on headphones, turn off the cell phone, and soft-pedal our way towards a temporary bliss? Dissociate the mind from the body in these instances. Find a way to give one the work while resting the other!”

Well said, Dr. Eisen. If only I weren’t my own worst patient?  From now on I will listen to you and my body.

Your Prescription For Training and Racing?

What is your approach to avoiding and dealing with cycling when sick?  Comment below.  Your fellow virtual cyclists want to know.


Want a second opinion from an elite eracer who is also a Doctor?  Check out this article by Jacqueline Godbe, MD, Ph.D.

To subscribe to the Zommunique and receive more informative and entertaining articles like this one sent directly to your inbox, click here!
Notify of

Inline Feedbacks
View all comments

The DIRT Dad Fund

Share the power of The DIRT Effect

Jaclyn Long, MFT

Certified Yoga & Mindfulness Teacher

Marriage & Family Therapist in CA

Sports Anxiety Therapy

Drink Coffee and Do Good!  

What could be better than that?

Click the Image and Shop now!

Related Articles

Would love your thoughts, please comment.x