Should You Exercise When You're Sick?

Whether or not to work out when you're sick is an age-old dilemma. Since it makes you stronger and healthier, we tend to think that it will help. And since no one wants to see their hard-earned fitness gains waste away, we want to keep up with our program. But when you consider what happens to your body, physiologically, during an illness and during exercise, you may see how this seemingly rational train of thought could lead you astray.

Common lore is to go ahead and exercise if your illness is above your neck and to rest if it's below. This generality is okay in some circumstances but not for most. So let's dig a little deeper and come up with the most rational plan for keeping your fitness goals intact.

What to do during times of high stress?

You're most susceptible to illness during times of excessive stress. These include, of course, the cold and flu season, which is easy to identify because it's when everyone else seems to be sick. But you're also at risk anytime your lifestyle changes. Seasonal change and travel are the two major offenders, but anytime your daily schedule is changing or being disrupted should be treated as a time of high stress.

When it comes to avoiding illness, the best defense is a good offense. Practicing good everyday habits is a great start. Identifying times of stress comes next. When you're under stress you certainly don't want to stop working out, since exercise helps your immune system stay strong. But you should also be hyperaware of how you're feeling during stress and take it easy anytime you feel that you might be at the onset of a cold.

When we're about to get sick our bodies' defenses are up, which can lead to a false sense of well-being. It's quite common to come down with a cold the day after having "the best workout of the year" or something similar. This is because your immune system is running overtime, so you feel good. Using this heightened state to run your best time or set your personal record for push-ups can deplete your last line of defense and, voila, you're under the weather. However, if you can identify this feeling and back off of your workout, your enhanced immune system has a very good chance of staving off the threatening illness.

What to do when we're sick

No matter how careful we are, sometimes we'll get sick anyway. Whether it's a mild cold or raging fever, at the initial stages of an illness your protocol should be the same; rest as much as you possibly can and don't do any more physical activity than is necessary.

To understand why, let's look at an oversimplified view of what happens to us when we work out:

Now let's look at an oversimplified view of what happens to us when we are sick:

When sick, you are essentially in a state of overtraining. Your body is working overtime to fight outside stress. As you can see from the above example, adding further stress, in the form of exercise, will further impede your body's ability to recover.

Looking back at the common lore, we must question how exercising with a head cold could possibly help. While it may be possible to exercise, it doesn't make sense to do so. You compromise your immune system by using its resources to recover from the exercise. Even if you have ample resources, it's unlikely that you have enough in reserve to both stave off the illness and recover well enough from the workout in order to benefit from it. If you had this much reserve, you probably wouldn't be sick. The best-case scenario in this situation is to not get sicker, essentially because you are compromised at both ends. There is virtually no chance that you will improve your fitness. (Chronic illness has a different set of circumstances as often exercise is needed to keep long-term deconditioning from occurring.)

What about losing your results?

Since you can't get more fit when you're ill, the best course of action is to minimize the illness. Rest and good nutrition is the best plan of attack. More often than not, those who attempt to train through an illness end up prolonging it, further reducing their state of fitness.

Conversely, a cold rarely lasts longer than a week. By resting effectively you can often knock this down to a few days. A few days of rest never hurts your fitness level. And if you're able to train harder, sooner, then the downtime you've had will be almost instantly reversed.

Coming off an illness

This is a point where the common lore can be applied. As long as you're feverish or achy, your illness is still in its acute phases. But once you're up and around, those lingering effects above the neck can often be improved with a workout.

Just make sure and start back slowly. Low-impact aerobic work such as Slim in 6® Start It Up! is the best way to test your system. If you feel good, increase the intensity the next day and so on. But if you feel weak, you've done too much and have put yourself at risk for a relapse, so back off and start over.

We often do things with the best of intentions that affect us in a negative manner. Irrational thinking, like "I'll lose fitness if I don't work out" or habitual thinking like "I feel better when I work out," can be hard to ignore. But by using the most basic science, along with an inkling of restraint, we can get through the cold and flu season with nary a blip on our fitness radar.