Can I Run When I Am Sick?
For many runners, the mental anguish caused by a day or two of missed training is far worse than any physical consequences of not being able to run. When sick, how does a runner know whether it is okay to continue running, or if a day of rest is best?
As a general rule of thumb, it is okay to train if the symptoms a runner is feeling are above the neck. If experiencing a mild headache, stuffy nose, or sore throat, a run may even make the sufferer feel better and more alert. In fact, researchers from the athletic training department at Ball State University tested the theory that running with a cold poses no additional risk1.
Scientists inoculated two groups of people with the common cold. One group remained sedentary while the second group ran for 30–40 minutes every day for a week. Among the two groups, there were no significant differences in how long it took for cold symptoms to disappear. However, caution should be used by the ill runner to make sure the effort during the run remains easy. All too often, runners who are feeling under the weather push too hard, which can cause an already weakened immune system to allow a simple cold to turn into a more serious illness.
A second study, published in 2003 by Schurr and Weidner, shows the effect of exercise on upper respiratory tract infection – specifically a cold – in sedentary subjects2.
All the subjects in this study were university students who were not particularly active. They were screened by a doctor to make sure they did not have a more serious infection or fever. The group was then split into two separate groups, one that was instructed to exercise on a treadmill, a stairmaster, or on a stationary bicycle at a moderate intensity for 30 minutes for five of the next seven days, and another which was instructed not to exercise at all.
The researchers found that there were no significant differences in the progression of the cold symptoms or in the recovery time between the two groups. In fact, students who had exercised had a slightly greater decrease in symptoms, meaning that the exercise aided their recovery.
When should an ill runner skip running altogether?
For any illness that includes fever, chills, body aches, nausea, diarrhea, or extreme fatigue, running should be avoided. In each instance, going for a run can not only increase recovery time, but could also potentially lead to worsened symptoms or illnesses. For instance, running with a high fever can trick the body into thinking the illness is worse than it truly is, which can lead to serious complications. During physical exertion, the body’s temperature naturally rises.
If running with an already high temperature, the body may be forced to shut down organs in order to avoid further damage. This serious outcome can lead to worse illnesses such as chronic fatigue syndrome.
Running when sick also opens the door to injury. When illness strikes, the body works efficiently to fight disease in the affected area of the body. However, areas of the body which are less important for critical processes, such as calf or hamstring muscles, may be more vulnerable. Exercising while ill can leave a runner more susceptible to strained or torn muscles, which ultimately leads to worse problems and longer recovery times.
Many runners worry about potential losses in fitness when having to take time off. According to running coach and Runner’s World contributor Hal Higdon, for every one day of training that is lost, it will take two days to rebuild. While this can be a scary prospect for a runner, especially for one who is training for a big race, the benefits of taking time off when sick far outweigh the consequences. Not only will complete rest help the body recover from illness more quickly, but it can also serve as a “blessing in disguise” for runners who may be on the verge of overtraining.
Typically, serious illnesses arise because of lapses in the immune system. For the majority of healthy runners, the immune system only breaks down because of sustained damage due to the inability to listen to one’s body or pushing too hard on days when recovery is necessary. The body has a way of indicating when drastic measures need to be taken, which is sometimes the reason illnesses arise.
Flu vs. Cold
There’s a fine difference between running with the flu and running with a cold. Symptoms, especially fever or achy muscles, are frequent when you have the flu. If your symptoms are congestion related – runny nose, coughing or chest congestion – you are usually safe to run.
On the same note, fever marks a rise in the body’s internal temperature because of viral or bacterial infections. Since running increases your internal temperature as well, it’s not recommended to train when experiencing these symptoms. Research has shown that running affects the immune system in the first 20 hours after vigorous exercise
What can a runner do to keep from losing too much fitness if he or she is unable to run while sick?
Although limited, there are certain exercises a runner can participate in when feeling under the weather. However, extreme care should be taken not to stress the body, and the runner should realize that exercises which typically require minimal effort during periods of good health will feel much more difficult when sick. Paying attention to heart rate is important, and it is recommended not to exceed 150–160 beats per minute during illness.
To sustain endurance, spinning and aqua jogging are recommended. Both activities are low impact and can be modified to accommodate the energy level of a runner who is sick. Aqua jogging can be especially beneficial, as being in water has a number of therapeutic benefits, including improved hydration, lymph drainage, and circulation. When completing these activities, exercise should remain light. Thirty to sixty minutes of easy spinning or aqua jogging, followed by a nutritious meal and bed rest is recommended. Light cardio exercise can be supplemented with at-home yoga sessions or light stretching. Yoga has been shown to decrease both blood pressure and stress levels, which may promote recovery, as well as keep muscles engaged during recovery.
For sinusitis sufferers, pool running can be a great alternative. Chlorine can be irritating to the nose, thus swimming is not recommended.
When coming back from an illness, runners should wait one to two days after symptoms disappear before resuming running. Even after symptoms subside, the immune system will still be weak, and too much physical activity can easily result in a relapse, leading to even more time off. Training should be modified depending on how many days of running were missed.
If one to three days were taken off, the first two days back should be kept light (30–40 minutes of easy running). After that, regular training can resume. If a week of running was missed, then a runner should not exceed more than 75% of the total mileage that was run in the week leading up to the illness. During the first week back, running should be light, with nothing more intense than strides. If two or more weeks were missed, the first week back should consist of no more than 50% of pre-sickness weekly mileage, and all runs should remain easy. During this stage, it is critical to listen to one’s body.
How can a runner avoid illness?
The keys to staying healthy include proper nutrition and hydration, good hygiene, adequate sleep, and proper recovery. The building blocks for a healthy immune system include protein, healthy fats, and certain vitamins and minerals. A well-rounded diet free of excess sugar, alcohol, and processed foods is recommended. The body also requires proper attention to hydration, especially during the winter months.
Sinus infections, which can result in missing up to a week of training, often begin with inflamed sinus tissues due to dry air. Proper hydration can minimize the risk of sinus inflammation. The risk of illness can also be minimized by practicing proper hygiene. Frequent hand washing is important for reducing the spread of disease. Finally, appropriate rest and recovery are also important for a properly working immune system. Without rest, the body must work extra hard in order to keep daily processes functioning normally, which weakens the body’s ability to fight off even the common cold.
While taking a few days off from training is never ideal, the reality is that it cannot be avoided. Even if you are able to “tough it out” and continue running, the risks of developing a more serious, or even chronic illness, are great. It is always best to take a day off early to avoid the sickness than to suffer while having to take multiple days off in a row. In the end, a day off in time saves nine!
1. Weidner, Thomas G., and Thomas L. Sevier. “Sport, Exercise, and the Common Cold.” Journal of Athletic Training 31.2 (1996): 154–159. Print.
2. Weidner, T, and T Schurr. “Effect of Exercise on Upper Respiratory Tract Infection in Sedentary Subjects.” British Journal of Sports Medicine 37.4 (2003): 304–306. PMC. Web. 6 Mar. 2016.
3. Fitzgerald L. 1988. Exercise and the immune system. Immunol Today. 9:337–339.