With the winter weather here, illness is all around us. The flu, colds, you name it: all can make going about your everyday routine exhausting and sometimes impossible. But what about your workout? Should you tough it out in hopes that you might be able to "sweat out the sickness", or do you rest completely until you feel 100% better?
How does your workout affect your immune system?
When you go through a high-intensity workout routine, a stress response is activated (in the form of the stress hormone cortisol). On a normal basis, your body can adapt to this. In fact, it's this progressive adaptation that actually leads to increased strength; however, when you're sick it's a different story. Being sick means your immune system is already compromised, and the added stress of a workout can be more than your body can handle.
Does this mean that you need to sit on the couch until you feel 100% better? Not necessarily. Non-strenuous activity doesn't invoke the same stress response as a high-intensity workout. Depending on the type of exercise you plan on doing, your body may be totally fine, and even benefit from some low-intensity movements. Working out when you're sick can actually help you recover faster, but you have to be smart about it, and only do what your body can handle?
What kinds of workouts are beneficial when sick?
Resistance training and other low-intensity movements are great for when you're feeling sick. These types of movements actually stimulate your innate immunity (otherwise known as your natural immunity). This can aid in fighting off whatever bug you've got in your system.
Low-intensity movements that get your blood flowing are best when you're feeling sick. These can include things like taking a walk outside, leisurely riding your bike, doing yoga, or even dancing around your kitchen. These movements cause you to take deep breaths which can help open up nasal passages (perfect for when you have a cold). Yoga in particular can be very beneficial because it's seen as a stress reliever. Since your body is going through extra stress when you're sick, yoga is a great way to combat that.
When should you stay home?
Even though you may want to try and "sweat out" your sickness, there are times when the best thing to do is do nothing. While low-intensity movements can be beneficial, there are certain symptoms that should make you take pause. Aches and pains, for example, are signs that your muscles are already too tired to handle even a low-intensity workout. A fever is another limiting symptom. When you have a fever, your body temperature is already high. A high-intensity workout causes an even greater increase in body temperature, which can make you sicker.
The most important thing to do is listen to your body. Everybody is at a different fitness level and used to different levels of exercise. The perceived exhaustion of someone who normally works out 6 days a week is going to be different than that of someone who only works out 3 days a week. What may work for you might not work for someone else, so there's really no concrete answer. Take stock of how your body is feeling on any particular day of your sickness, and evaluate on a day-to-day basis what activity you can handle.