Inevitably, even those super-humans among us get sick. No problem. You'll take care of the cold in just a few days. No big deal.
I believe you, but what I don't know is how you plan on getting back. Or, what you did while you were sick and how long you were in denial about being sick, under-recovered, malnourished, or whatever other label we can place on the fact that you were not 100%, so neither was your performance.
It came up last week, as it will many times in the future, and has many times in the past: "what do I do on my first workout back after being sick?"
Great question. The default among endurance athletes seems to be this thing called the "easy run". You say to yourself, "ah, I'll just go out easy and see how it feels." I'm not telling you to avoid that, but I am telling you to listen to your bodies a bit more closely.
When you are sick, you are likely moving less. Especially if the illness is at all more than the common cold and involves any kind of fever. Thus, you want to make sure you are able to move is your first task coming back from being ill.
How do you do that? Well, move through your full range of motion. When you are better able to move, you are better able to recover. It's actually a matter of circulation. Feel free to jump ahead if you don't want to read some physiology, but I'll try to keep it brief.
First, you must understand what an increase in circulation actually means. In essence, using a basic formula called Poiseuille's law: Flow = (Pressure gradient * Vessel radius) / (Vessel length * Fluid viscosity). You see that several factors are important at even the basic level. What does this equation mean to you? Well, if you break it down, the only thing that really matters is the vessel radius because it is the only factor that your body can change quickly and "voluntarily". Thus, to increase bloodflow throughout your body, you need to figure out a way to open up your blood vessels.
Here is where movement comes in. We know that the best ways to stimulate vasodilation (vessel radius increase) are to warm up the body so that it attempts to cool itself down, and then also to utilize the mechanical action of muscle to compound the cardiovascular system's efforts to move blood through the body. If you move at low intensity, as though warming up, your physiological systems exist in this cool "bridge" between the sympathetic and parasympathetic nervous systems responses.
On the parasympathetic side, you have stimulated digestion and increased dilation of gut blood vessels. With moderate exercise, you get an accelerated heart beat and adrenal preparation for the release of important hormones that you will need if you start doing intense exercise. When doing moderate work (< 50% of VO2max), you have a slightly elevated heart rate without the sympathetic system being fully stimulated. Additionally, many of the capillaries that were dormant at rest will dilate allowing for, most importantly, increased ability for the exchange of nutrient and gases. which gives you a taste of both worlds. I think that's pretty neat, except for when it's used incorrectly.
When I say incorrectly using moderate-intensity exercise, I mean going for an easy run or bike ride under the assumption that you are increasing blood flow throughout the body. While you may be, that assumes perfect biomechanics (and incidentally, movement in your upper body, so cycling's out). My guess is, even without knowing you, but I think you might agree, your heart rate may not stay below that 50% VO2max number after being sick. What do I suggest? Well, what moves you through a full range of motion, slightly elevates your heart rate, tries its best to simulate parasympathetic nervous system response, and elevates some other great physiological responses by being in a community setting? Well, yoga.
There are obviously other ways of gaining the same responses, but yoga seems to fit all of those categories while forcing the majority of us (who no doubt spend too many hours sitting at desks) to work on our mechanics. You body was built to move. Let it.
