Should You Exercise When You Are Sick ?

Tuesday, October 23, 2018 - 14:15

We all get sick from time to time, but we don’t always know how to handle it. Do we sweat it out? Or do we get some rest instead? Most times we choose to “sweat it out.”

So, you are at your friendly neighborhood gym. You are all warmed up and ready for a great beastly workout session. Then, all the sudden, Mr. Sneezy walks by with coughing, sniffling, and heavy mouth breathing. He’s spraying all over the benches and mats. “Dude, shouldn’t you just stay home and rest?” you’re thinking. (And, while you’re at it, stop sharing those nasty germs?) But maybe Mr. Sneezy’s onto something. Maybe he’ll be able to sweat the sickness out of his system, boosting his immune system along the way. What’s the right approach? Let’s explore.

Every single day, bacteria, viruses, fungi, and parasites come at us. Folks, it’s a germ jungle out there. The most common invaders are upper respiratory tract invaders, or URTI’s. Yep, I’m talking about colds, coughs, influenza, sinusitis, tonsillitis, throat infections, and middle ear infections. Luckily, our immune system has got a plan when it is faced with a foreign attack as it works hard to defend us. Without the immune system, we’d never have a healthy day in our lives.

Our immune cells originate in our bone marrow and thymus. They interact with invaders through the lymph nodes, the spleen, and mucus membranes. This means they first make contact in your mouth, gut, lungs, and urinary tract. So, should we really be exercising while we are sick? Well let’s get one thing clear from the start: there’s a difference between “working out” and “physically moving the body.”

A structured workout routine is one where you’re breathing heavily, sweating, working hard, and feeling some discomfort that awakens a stress response in the body. When we’re healthy, our bodies can easily adapt to that stress. Over time, this progressive adaptation is precisely what makes us fitter and stronger but when we are sick, the stress of a tough workout can be a bit more than our immune systems can handle.

Still, there’s no reason to dive for the couch the minute you feel the sniffles coming on. Unless you’re severely out of shape, non-strenuous movements like walking outdoors, low-intensity bike riding, gardening or even t’ai-chi shouldn’t hurt you — and it might even help. In fact, all of these activities can slowly boost immune system. 

What about an actual workout? Non-strenuous movement and purposefully working out are different. There are low intensity workouts and high intensity workouts — and all sorts of workouts in between. But what’s low to one person might be high to another. So let your own perceived level of exertion be your guide. In general, a low to moderate intensity workout will leave you feeling energized. A high intensity workout, on the other hand, goes to a different extreme. If you are sick, it makes sense to avoid over exerting yourself. 

Exercise may play a role in both our innate and our adaptive immune response and affects our immune system in a big way. Here’s how:

After one prolonged vigorous exercise session we’re more susceptible to infection. For example, running a marathon may temporarily depress the adaptive immune system for up to 72 hours. This is why so many endurance athletes get sick right after races.

However, one brief vigorous exercise session doesn’t cause the same immune-suppressing effect. Further, just one moderate intensity exercise session can actually boost immunity in healthy folks.

Interestingly, chronic resistance training seems to stimulate innate (but not adaptive) immunity. While chronic moderate exercise seems to strengthen the adaptive immune system.

In the end, here’s the pattern:

Consistent, moderate exercise and resistance training can strengthen the immune system over time. So, by all means, train hard while you’re healthy.

But single high intensity or long duration exercise sessions can interfere with immune function. So take it easy when you’re feeling sick.

So to avoid a crash in the immune system maintain a moderate workout schedule, be sure to get at least eight hours rest, include supplementation along with proper daily nutrition and drink at least three litres of water daily.