Ill Before Your Race? 12 Tips On How to Respond

Why you're more likely to get sick during training, when you should vs shouldn't run, how to take care of it, and how to minimize the chances of it happening again.

Many runners get sick in the run up up to their race. In fact, almost half (40%) of marathoners experience at least a cold in the two months leading up to their race.1Nieman, D. C., Johanssen, L. M., Lee, J. W., & Arabatzis, K. (1990). Infectious episodes in runners before and after the Los Angeles Marathon. The Journal of Sports Medicine and Physical Fitness30(3), 316–328.

Furthermore, in the 3 to 72 hours after a marathon, runners are also at increased risk for illness—making it very common to get sick in the 2 weeks following an endurance race.2Nieman, D. C. (1997). Risk of upper respiratory tract infection in athletes: an epidemiologic and immunologic perspective. Journal of Athletic Training32(4), 344–349.


Well, after periods of intense physical activity (such as peak training-weeks and the marathon itself) your body is in a state of exhaustion, which leads to a temporarily repressed immune system.

Understandably, getting ill before a race can cause panic and leave you looking for reassurance and answers to questions such as:

How should you respond when you get ill before your race?

How can you know when you should push through the discomfort and when the illness is too serious to be ignored?

Is there anything you can do to get healthy fast before your big race?

Well, look no further. We chatted to the health professionals and running coaches to get the answers. 

a lady bending over with her hand to her chest

Why do you get sick before a race?

David Nieman, a researcher and professor in exercise physiology, explains this through his “open window theory.” (Related: David Nieman: Ibuprofen and Running, Negative Effects and Substitutes).3loveas. (2019, November 26). Dr. David C. Nieman, DrPH, FACSM. Dr. David C. Nieman, DrPH, FACSM.

In Nieman’s research, he found that runners commonly get sick during tapering and after a marathon in an ‘open window’ of 3 – 72 hours in which the immune system is suppressed. 

Nieman explains that moderate exercise prompts immune cells to circulate around at a greater rate than normal which gives them a better chance of running into bad germs and protecting you. 

But, when you rigorously train such as doing long runs, your exhausted muscles need fuel to repair, so the immune system is overworked and has lots to do—making them ‘too confused’ to do their jobs well.

Other factors such as mental stress, and poor sleep and diet can also impair immune function.

So, if your long runs are not paired with extra food and extra rest, you increase your risk of getting sick. 

First time marathon runners with a lower fitness level may be more vulnerable to these effects.

a running race viewed from a bird's eye view

Can you run a marathon while sick?

You can still run a marathon while sick if the illness is not severe. 

Many runners, including running coach Kaila Morgante, say they feel better when they go for a run.4Instagram. (n.d.). Retrieved April 16, 2024, from

“I just want to go outside and shake it out,” she says. “But a run can either boost our immune system or compromise it.

…So, where is the line?

Thomas Eichner, professor of medicine, came up with the ‘neck check’ to help runners decipher when it is safe to try a run when ill.5Eichner, E. R. (1993). Infection, Immunity, and Exercise. The Physician and Sportsmedicine21(1), 125–135.

With the neck check, you can run your marathon (with caution) if you have only above-the-neck symptoms, such as a runny nose, sneezing, and scratchy throat. 

What kind of illness should you NOT run with?

With Eichner’s neck check, if your symptoms are below the neck on the day of your marathon, you should not run. 

Do not run your marathon if you are ill with a fever, difficulty breathing, muscle aches and strong body aches, diarrhea, swollen lymph nodes, extreme tiredness, vomiting, a very sore throat, or a hacking cough that produces phlegm in your throat. 

a man running on a road

If you have a pounding headache or you just feel lousy even thinking about running, rest instead. 

In the days ahead of your marathon, you can do a test run (short and easy) as a shake-out and see how you feel. If you feel worse, you may need to push back your race date.

“Why go against Mother Nature?” Eichner told the LA Times. “It’s foolhardy to do a workout when your system is calling for rest,” adding that doing so puts a runner at risk for a more serious infection.6Krucoff, C. (1998, December 28). A Little Exercise May Help That Head Cold. Los Angeles Times.

Related: Here Are The 11 Worst Things To Do Before A Race

Can you run with a cold?

Yes, if your cold symptoms are localized to your head without a cough, you can still run your marathon with a cold.

The American College of Sports Medicine has said that exercising moderately with a head cold is “probably acceptable” and perhaps even beneficial.7Mazzeo, R. (n.d.). ACSM FIT SOCIETY ® PAGE Inflammation, Disease and Exercise. Retrieved April 16, 2024, from

However, running a marathon is not moderate.

Therefore, you should still proceed with caution.

a lady running next to the ocean

Related: Running with a Cold: Should You Do It?

It’s important to note that Nieman’s research also suggests moderate exercise (roughly less than 60 miles per week, for less than 60 minutes) boosts immunity and helps prevent colds. 

So… yes! Running does make us healthier! But peak marathon training can take a toll. 

What can you do if you get sick before a race?

There are several actions you can take to help you beat your illness before arriving at the start line on race day. 

Note: All these tips are useful for runners tapering for a full marathon and crucial for marathon runners who are ill before their marathon. They also apply to half marathon runners.

#1: Eat well and get in all your nutrition.

Eat a healthy balanced diet to keep your immune system strong and ready for your marathon. 

Fruits and vegetables that are rich in antioxidants should make up a large part (about 75 percent) of your diet. 

When your immune system is doing hard work, it undergoes oxidative stress. Antioxidants help it recover so it can keep fighting.  

In addition to healthy carbs, aim for a rainbow of colours when choosing foods in the produce aisle such as: red peppers, apples, and strawberries, orange carrots and oranges, yellow squash, leafy greens, and blueberries. 

#2: Get lots of sleep.

Aim for at least 8 hours each night, says Todd Buckingham, lead exercise physiologist at Mary Free Bed Rehabilitation Hospital.8Mary Free Bed Rehabilitation Hospital: Home. (n.d.). Mary Free Bed Rehabilitation Hospital.

Sleep is the most important performance and recovery tool in your arsenal”, adding that deep sleep is when our bodies repair themselves.9Milewski, M. D., Skaggs, D. L., Bishop, G. A., Pace, J. L., Ibrahim, D. A., Wren, T. A. L., & Barzdukas, A. (2014). Chronic lack of sleep is associated with increased sports injuries in adolescent athletes. Journal of Pediatric Orthopedics34(2), 129–133.

runner's feet during a a race

If you’re unable to get 8 hours a night, try to get short naps no longer than 30 minutes before 3 p.m. These can also aid your body in recovery. 

#3: Take a hot shower. 

“A warm shower can help clear congestion and cause your muscles to relax, aiding in the recovery process” adds Buckingham.

“A shower can be very soothing. And the heat will cause blood vessels in your sinus cavity and lungs to dilate, which will cause you to feel less congested,” he says.  

#4: Drink lots of fluids.

Staying hydrated helps your immune system work optimally by aiding the transport of oxygen to your body cells.

Liquids can also help your body remove toxins that negatively impact your immune system. 

And, don’t stick to just water, adds Buckingham. 

If you drink only water, it could dilute blood sodium levels. Chicken noodle soup is great for consuming some extra sodium when you’re not feeling well. There’s a reason your mom made it for you when you were sick as a kid!”

people running next to the sea

#5: Take a probiotic.

Research shows that seventy percent of your immune system lives in your gut. This is because your gut microbes help determine inflammation and the level of impairment to your immune system.10Cohen, S. (2021, March 19). Want to boost immunity? Look to the gut. Https://

To keep your gut healthy, eat lots of plants and seeds with fiber and antioxidants (like mentioned above), add in healthy fats, yogurt, sauerkraut, and take a probiotic. 

These actions will help keep your gut full of the right microbes which helps keep your immune system at full steam. 

#6: Go for a walk (when you feel up for it).

a runnning race

As noted, exercise is good for your immune system. So, when you feel stronger, do some very light exercise like go for a walk or easy bike ride

Light physical activity can help you recover from an illness faster. Increasing blood flow will help transport white blood cells and nutrients to and remove waste products from the area,” adds Buckingham. 

This walk will also help you assess if you are ready for a run yet.

Related: Should You Run Before a Race? Shakeout Runs Explained

#7: Limit your time spent around sick people.

You are still in the danger zone of getting sick after your endurance run, so be sure to limit your exposure to people, especially sick people, says Ethan Lahav, a certified running coach.

“If you can’t avoid being around sick people, try to wash your hands often.”

Keep up your rest, hydration, and healthy diet after the marathon to help you heal your illness and recover from the marathon.

Related: How to Start Running Again After a Break

a man a woman running next to a body of water

5 Steps to get healthier before your race.

If become ill the week of the marathon, here is a step-by-step guide to get healthy: 

Step 1: Rest.

Sleep and rest completely. “If you are severely sick and cannot run at all, then this is a must,” says Lahav.

Step 2: Wait, then Walk.

If you begin to feel better, wait a day. Then try to go for a walk. “This will gently help your body recover from the illness and avoid stressing yourself out from running,” says Lahav. 

Step 3: Easy Test Run.

Once you feel like you are recovering, ease back into your training by doing a very easy test run.

Do not stick to the schedule you had before you got sick. For easy runs, aim for less than a 15-minute jog. 

Step 4: Short Run.

If this feels good, try to complete a short run the next day. “This will help aid your recovery and make you feel more confident about race day,” he says. 

If you are unable to complete a short run without it wearing you out, then you should not run your race.

runner shoes and finisher medal on grass

Step 5: Sleep, East, Hydrate.

Eat well, hydrate, and get lots of sleep. This is a given any time you are sick, whether that be outside of training, during any weeks of training, or during your marathon taper —so do this in spades, before and after the race!

Running a marathon? Check this First!

If you are planning to train for a marathon, we would love to help you! Check out our marathon training resources including training guides and training plans to help build up your fitness safely and sustainably.


Photo of author
Whitney Heins is the founder of The Mother Runners and a VDOT-O2 certified running coach. She lives in Knoxville, TN with her two crazy, beautiful kids, pups, and husband. She is currently training to qualify for the US Olympic Trials marathon.

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