Running While Sick: How-To Guide + 5 Tips For Ultimate Health

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One of the best things about running is the ability to exercise and be happily active year-round with few limitations on conditions, gear, or time of day. But what happens when you are ready for your run and start feeling crummy? Is running while sick a viable option?

What if you wake up with a headache, sore throat, or even worse, body aches, and a fever? Do you push on and keep up your habit, or do you lay low and let your body heal?

In this article, you will learn how to tell if you are genuinely sick or are just feeling under the weather. We will also offer practical advice for maintaining your active lifestyle while ill and give you five tips for running while sick.

We will discuss:

  • Running During Seasonal Illness
  • How To Determine If You Are Sick Or Just Under The Weather
  • Running While Sick With A Cold
  • Nutrition While You Are Sick
  • Hydration While You Are Sick
  • Can Running Make Illness Worse?
  • When Should You Return to Exercise After Being Sick?
  • What Type of Exercise is Best When Coming Back From Illness?
  • What to Consider When Running While Sick
  • 5 Tips For Running While Sick


Let’s jump in!

Woman sick on a couch blowing her nose looking at the computer.

Running During Seasonal Illness

Winter months are notorious for sickness with more time spent indoors, people gathering in tight quarters, and reduced amounts of daily sunlight. Under these circumstances, our natural inclination is to hibernate.

That’s not to say that people don’t get sick year-round, but the general lack of Vitamin D from natural sunlight and reduced overall movement stresses our immune system’s ability to fight infections. 

Spring, summer, and fall bring unique immune stressors as the temperatures change and nature’s blooms challenge those with allergies. Allergy sufferers can usually tell the difference between allergy and illness, and the clues are typically based on the season.

It is very good for overall health to get outside in the wintertime, given you have proper cold-weather gear.

A man sneezing into a tissue.

Are You Sick or Just Under the Weather?

Sometimes it’s hard to distinguish between feeling unwell from a head cold or sore throat and being ill. 

An unwelcome virus or bacterium that overwhelms your immune system can make you pretty sick, and it’s essential to know the difference between having a “cold” or being sick from something like the “flu.”

Winter Colds

You wake up with a sore throat and perhaps a sniffle in the morning. So what is it, and how do you know if you have a cold? The most common cold symptoms are:

  • Headache
  • Runny nose with clear mucous
  • Sore throat
  • Mild dry cough (no mucous production)

Viruses cause most colds, and the body fights viruses by producing white blood cells that target them. As long as your immune system is strong, your body should be able to tackle the “common cold” and progress toward full recovery, which is when you start feeling better.

A man lying down holding his forehead.

The Flu

But what if what you have is something worse like the flu? 

The most common symptoms of a flu-like illness are similar to having a cold, but there are distinct differences to keep in mind:

  • Headache
  • Runny nose with mucous that becomes thick and green or yellow
  • Sore throat with possibly swollen lymph nodes
  • Cough with mucous production
  • FEVER (37.7 degrees centigrade or 100 degrees Fahrenheit)

A strain of the influenza virus causes the flu, and the body fights this the same way as common cold viruses, but influenza can make people much sicker than the common cold.  

If you have access to the flu shot and can get it in the fall, this is a great way to help you stay active. The flu shot contains a piece of the virus that allows your immune system to remember it and fight it faster and more efficiently once your body reencounters it.

The same happens when we fight a cold-causing virus. As long as your immune system is strong, your body should be able to tackle the flu and progress toward full recovery.

A woman on a couch covered in a blanket blowing her nose.

Running While Sick with a Cold

Although you may feel crummy, running or light strength training when sick with a cold is usually not harmful and may help you recover faster. Generalized activity keeps your fluids circulating and muscles and joints loose, and better able to utilize oxygen and get rid of toxins.

Should you be running while sick?

Most medical experts will tell you that the answer depends on various factors, such as your tolerance for discomfort, how bad the symptoms are, and which symptoms you have

It may be okay to run or strength train with a headache or a slight cold, but it is better to stay in and regenerate with fluids and rest if you start running a fever. Some doctors will recommend the following: if your symptoms are limited to a headache and runny nose, continuing activity is acceptable

The type and intensity of each activity will vary based on how you feel

Unlike pushing your limits when you feel well, pushing your physical limitations when you are sick may make it harder for your body to repair your muscles and fight off the infection.  

It’s okay not to go all out during a workout when you’re sick. Light cardio activity such as walking, stretching with yoga, or an easy pilates session will be good for your overall health.

A small chalkboard with the words "vitamin d" surrounded by eggs, cottage cheese, fish, milk, cheese, and beans.

Nutrition is Important, Especially When You’re Ill

Maintaining optimal nutrition while ill is essential to support your already hard-working immune system. Just as maintaining physical activity is critical to overcoming illness, don’t forget to continue your supplements or complement with others such as vitamin C, vitamin E, vitamin A, folate, iron, selenium, and zinc. 

Vitamin D

If you live in the Northern hemisphere, chances are you aren’t getting enough sunlight, which is the best source of vitamin D.  Vitamin D is vital for maintaining normal immune system function, helping absorb calcium and phosphorous, and may also help regulate mood.

Supplements are available in most places. Also, your doctor can quickly check vitamin D blood levels and prescribe a supplement if necessary.    

Some food rich in vitamin D are canned fish, salmon, milk, yogurt, egg yolks, mushrooms, soy products, and kefir drinks. If you don’t have access to fresh fruits and vegetables, frozen can be just as good! Most frozen vegetables and fruits are picked at peak ripeness and immediately frozen, so they remain in a state of optimal nutritional value.  

5 different small bowls filled with supplements.

Other Supplements

Other vitamins and minerals necessary for solid immune health are vitamin C, vitamin E, vitamin A, folate, iron, selenium, and zinc. These are all readily available in a variety of vegetables and fruits. Soups and stews are excellent ways to keep up with vegetable intake in the winter months, and the warm broths will help your body absorb the nutrients.

Hydration While Sick: Not Just For Sweaty Summers

Dehydration in the winter months is prevalent! During the months when we feel cooler, it is natural to drink less. However, when you exercise in cold weather, your body sweats just as much as in warmer temperatures, we don’t recognize it, and our thirst mechanisms may not kick in as frequently.

A dehydrated state is unhealthy because it doesn’t allow optimal cardiovascular, musculoskeletal, or immune system functions. When you are ill, it is even more important to stay hydrated to jump on the path to a faster recovery.

A glass of water with lemon slices.

Can Running Make My Illness Worse?

Putting your body through rigorous exercise also puts stress on your immune system. When we exercise, the immune system is busy repairing small tears in our muscles, and oxygen is being delivered preferentially to the muscle groups working the hardest. Hence, the body has to work even harder to fight infection.

If you are fighting a cold or something worse, you want to be able to resist the infection with all of your systems working at optimal capacity. 

However, when you have a slight cold (symptoms from the neck up and no fever), light exercise could help you recover faster. If you develop a fever or cough, this is the time to forego a run and perhaps do low-impact work such as stretching or gentle yoga. 

When Should I Return to Exercise?

The best time to return to your regular routine is based on how you feel and whether your symptoms improve. 

Each person recovers at a different rate. Some people feel better running after a fever passes, but the headache remains. Others would rather wait until they feel completely back to “normal” before heading out for a run or exercise.

The other piece to consider is to avoid group fitness when you’re sick. Most colds and flu cases present a runny nose and cough, and you may be putting others at risk if you bring the illness into the gym. 

If you’re not completely recovered but want to get moving, consider running outside. The fresh air is better for your overall health than being indoors.

A woman walking on a road.

What Type of Exercise is Best When Coming Back From Illness?

The type of exercise you choose depends on several factors, including your baseline level of fitness, the severity of the illness, residual symptoms, and energy levels. You should pay attention to all of these when considering how to return to your exercise routine.

For example, if you had a cold for several days and were mainly sedentary, start with a brisk walk outside and see how you feel. If your heart rate remains steady and your breathing isn’t labored, you could increase to a jog or run. 

Suppose you had the flu and could not do much of anything; you may want to start back more gradually with gentle stretching and a walk. If your symptoms return or worsen, you may wish to consult with a doctor before returning to exercise to be sure you are fully recovered.

What to Consider When Running While Sick

The keys to keeping you running and active when you are under the weather are: reducing the intensity, protecting yourself from the elements, and hydration. Let’s check these out in a bit more detail: 

#1: Reducing Intensity

If you are used to running at a certain intensity level, consider cutting back by 10-20% if you feel unwell. Your body may be able to keep up the same duration, but the lower intensity will allow you to recover faster from the run and your illness.

#2: Protection From the Elements

Did you know that 7 percent of the heat you produce is lost from your head? Overall, the amount of heat lost is proportional to the amount of uncovered skin. Depending on the weather, cover those exposed areas. 

Moisture-wicking clothing is best. We lose a lot of heat from our bodies while wearing wet clothes. It is also wise to keep warm air entering your lungs, so our infection clearing mechanisms work well; once we inhale cold air, our blood vessels and airways tend to clamp down and don’t work as well as when they’re wide open.

Running while sick? Bundle up. Here we have a woman jogging with long-sleeves, gloves, and a warm headband.

#3: Hydration

Sweating is our body’s way of evaporative cooling, and the wind dries the sweat and our skin very quickly, so we tend to lose more moisture in windy conditions. Make sure to drink plenty of water before and after your run and lots of warm liquids such as warm tea, warm water with lemon (vitamin C) broth, and soups throughout the day.

Five Tips For Running While Sick

Here are five tips for running while sick year-round:

  1. Hydrate often pre and post-run with a focus on replacing more than you think you lost, especially in colder months.
  2. Wear weather appropriate clothing, block the wind and wear a running scarf to warm your breath if it’s a cold day.
  3. Reduce the intensity of your normal workout.
  4. Exercise solo, and outside if possible.
  5. Don’t forget that gentle walks, stretching or yoga and meditation are all fantastic activities to support you as a runner and great to do when you are sick!

Now that you can determine if running while sick is a good choice for you and what alternatives you have if running isn’t the best option let’s try and avoid getting sick in the first place! Here are some helpful tips for healthy eating for runners to keep their bodies in tip-top shape:

Running Nutrition Guide: What To Eat For Runners

The Best Popular Diets For Runners: 3 Healthy Choices

A woman with crossed legs performing a yoga pose.
Photo of author
I am a native Texan, born to run, enjoy and live life outdoors. My medical career has allowed me to live in Philadelphia, Boston, San Antonio, Minneapolis, and now Columbus Ohio. I am trained as a general surgeon, have practiced acute care, trauma, burn, and general surgery. I've traveled and found running groups throughout Europe and Singapore. My favorite sports are whatever my kids are playing. I run to feel great! Favorite running companion is CrossFit, favorite hobbies are cooking and travel! Goal: Can't wait to run my first International Marathon!

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