There is nothing more frustrating than developing a case of the sniffles in the middle of your training. You may have every desire to keep your training schedule on track but you might be unsure about how running with a cold might impact your long-term goals and short-term health.
Scientific studies have investigated the role of exercise on illness—specifically colds and respiratory infections. Based on the evidence, there are a few simple rules that can help you decide whether to run or stay home.
Running With a Cold
Medical experts advise that you use a basic rule to determine whether you should or shouldn't run with a cold. The rule is based on the location of your symptoms. In short, assess how you feel and determine whether your symptoms are above or below the neck. Above the neck symptoms means you can typically run with a cold safely. If your symptoms are below the neck, such as chest congestion, skip your run until you feel better. Here is a closer look at what you should consider.
The Neck Rule
The above-the-neck/below-the-neck rule is a tried and true test that you can use when deciding whether it is appropriate to train.
Headache
Runny or stuffy nose
Sore throat
Sneezing
Watery eyes
Chest congestion and coughing
Body aches
Fever
Fatigue
Vomiting/diarrhea
According to the rules, you can continue running if your symptoms are manageable and "above the neck," including a headache, runny nose, watery eyes, sore throat, or sneezing, which suggests that you have a run-of-the-mill cold.
Any symptom "below the neck," however, such as chest congestion, coughing, body aches, vomiting, or diarrhea is a sign of more serious illness that likely requires some rest. Training may do more harm than good.
Just because your symptoms are "above the neck" doesn't mean you should train. If you do decide to run, take it easy, and stop if your symptoms get worse or become unmanageable.
Exceptions to the Rule
As with most rules, there are important exceptions to the neck rule. "Full-body" symptoms like a fever should give you pause, even if it's relatively low-grade. While a fever may accompany seasonal allergies, it is more often an indication of a developing infection. If in doubt, it is best to err on the side of caution and take it easy.
Similarly, dizziness should never be taken lightly. There could be any number of reasons why dizziness occurs, from a drop in blood pressure to a middle ear infection. Whatever the cause, it may not be safe to run if your balance is affected. Use your best judgment, and see a doctor if the symptoms do not improve.
There are times when nasal congestion is bad enough that your respiration is significantly impaired. If you have a "nose cold" and find yourself breathing entirely through the mouth, you may want to think twice about running.
While a nasal decongestant may help, it is best to stop training if you find yourself gasping for air or feeling lightheaded. Until you are breathing freely again, you may want to limit yourself to walking or weight training.
Cold vs. Allergy Symptoms
The above-the-neck rule suggests that symptoms limited to the head are inherently less severe. And, in large part, that's true given that above-the-neck symptoms are most commonly associated with allergies and colds.
Certainly, with an allergy, you can usually manage exercise without compromising your health. Even severe allergy symptoms can be treated without the risk of major complications.
The same cannot be said for the common cold. If not managed reasonably, the viral infection can worsen and lead to any number of complications, including strep throat, ear infections, bronchitis, or pneumonia.
For this reason, you need to be able to read the signs for experiencing above-the-neck symptoms. In some cases, what you assume is hay fever may actually be the early signs of a cold or flu.
Allergies vs. Cold/Flu
- Allergies can cause fatigue with exertion; colds and flu cause fatigue when at rest.
- Allergies are generally not accompanied by fever; colds and flu commonly are.
- Allergies are often accompanied by rash and itchiness; colds and flu aren't.
- Allergies do not cause body aches; colds and flu can.
How Exercise Affects Illness
Many people will force themselves to exercise at the first sign of illness, believing that it will "boost" their immune system. Insights published in the journal Muscle and Exercise Physiology reveal that while moderate exercise does help boost the immune system and improve. However, other researchers note that there have not yet been sufficient studies to quantify the effects of exercise on immunology and preventing the common cold.
In fact, some research does suggest that immune function drops and infection risk rises with higher intensity workouts and prolonged periods of exercise.
According to the research, moderate exercise stimulates the production of a type of white blood cell known as helper T-cell 1 (Th1) which the body uses to neutralize viruses and bacteria.
Increased exercise may trigger an exaggerated Th1 response. When this happens, the immune system, suddenly on high alert, will flood the body with inflammatory cytokines that end up damaging respiratory tissues and accelerating the progression of the disease.
A review of studies conducted by Cochrane researchers concluded that based on current evidence, they could not determine "whether exercise is effective at altering the occurrence, severity, or duration of acute respiratory infections." While some studies found exercise to be helpful in reducing symptoms and the days of illness per episode, the researchers noted that the quality of studies was poor.
Should You Run With a Cold?
The tipping point between the prevention and promotion of illness can vary between one athlete and the next. While the above-the-neck/below-the-neck rule can certainly help, common sense should always prevail.
Running With a Cold: How to Decide
- If you develop symptoms above the neck, reduce the intensity and/or duration of your training by 50%.
- If the symptoms are below the neck, stay at home, and allow your immune system to fully recover. Always treat a cold or flu appropriately with plenty of rest and fluids.
- Once you feel better, don't barrel back into training. Start at 75% and gradually increase to full intensity by the end of the week.
A Word From Verywell
Finally, wherever your symptoms may be—above the neck or below the neck—be courteous to those around you if there is any chance you're contagious. Wash your hands regularly and stay well away from others if you are coughing or sneezing.