Why do I get sick after a race?

April fool's 4 miler

Last year I wrote a blog post, Why do I get a cold after a race?

In that post I wrote about the ways that runners can pick up germs at a race. My post was based on my observations of what runners do at races and during races. There are many ways that runners exchange germs at races and I talked about the importance of keeping your hands clean.

The science behind a compromised immune system

My previous post was about how to avoid picking up germs and how to keep them out of your body. Here is some information on why you are more susceptible to these germs after a race.

A 2012 article from Outside Online discussed how an athlete’s immune system is weakened. In the article, Outside cites a study published in Exercise Immunology Review in late 2011 outlining what they currently know.

To paraphrase:

While researchers still have a lot to learn about the complexities of our immune system and how it works, they do believe there’s an “open window” of impaired immunity that may last between three hours and three days after a big event. During that time, your body’s resistance to pathogens is lowered, leaving you at higher risk for infection.

Livestrong.com posted an article in October of 2013, Sickness After Running a Marathon which helps explain why you are vulnerable for up to three days after an event.

Why Runners Get Sick

While moderate exercise has been shown to improve the body’s immunity to disease, periods of strenuous exercise lasting longer than 90 minutes can weaken the body’s immune system. After about 90 minutes, depending on a runner’s reserve of carbohydrate energy, the body uses up its natural energy supply of glucose, triggering the release of the stress molecule cortisol. Higher levels of cortisol, in turn, can weaken the immune system and make the body more susceptible to infection, “Marathon & Beyond” magazine explains, most commonly upper respiratory tract infections. – from www.livestong.com.

The article goes on to recommend getting plenty of rest after a marathon to allow the body’s stress levels to return to normal. In addition to a good night’s sleep, a nap may not be a bad idea either. They also recommend replenishing your body’s carbohydrate stores and getting plenty of vitamins and minerals through fresh fruit and vegetables.

Energy Supplements

Runners often supplement their natural stores of energy with energy products. Your body can absorb about 350 calories per hour, but can burn more than 600 calories per hour during a marathon or strenuous workout. Even if you manage to ingest 350 calories per hour you will eventually run an energy deficit during a marathon. You cannot avoid running down your natural reserves.

How to reduce your chances of getting sick?

  • Protect your self from common sources of germs at a race
  • Refuel properly after a race – see Additional resources below.
  • Get plenty of rest before and after a race.

Additional Resources

Here is a post from Greatest.com that discusses the virtues of chocolate milk as a post race or exercise beverage. The low-cost is one to keep in mind.

Here is a good review of energy products written by All Season Cyclist. lots of good information here on products you are probably using all ready.

At Get Going, Get Running, Bernie writes about how he uses nutritional supplements while training for a race and during a race.

Run well my friends!


Author: OmniRunner

10 time Boston Marathon finisher, and 20 marathons in total. Sharing my love for running and the fun adventures and lessons that come with it. Helping non-profits increase fundraising and new runners celebrate their First 5K.

6 thoughts on “Why do I get sick after a race?”

  1. Make a lot of sense. It takes a lot to repair muscles, so it must take down your immunity from fighting other stuff.

    Of course yesterday I was worried about getting hit by another runner’s snot rocket. So gross.

  2. Thanks for sharing this. Might explain why I’ve been feeling under the weather since a race on Sunday.

    1. Thanks for stopping by and your comment.

      I think we often get so focused on the race or just don’t think about the environment. A few precautions can go a long way to staying healthy.

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