Immunonutrition: Eating to Avoid Illness as an Endurance Athlete

 Since exercise is supposed to make us healthy and stuff, you’d think endurance athletes, who spend countless hours running, cycling, paddling, swimming, or (insert action verb here)-ing would be the healthiest kids on the block, right?

Weird thing is, we’re not. We’re a notoriously phlegmy demographic—and with good reason, given all the heppest researchers know that any effort lasting over 90 minutes can cause a dip in immune function lasting anywhere from 3 to 24 hours.  And upping the intensity of your training or skipping feeds just makes it all the worse.

Happily, there are a few things you can do to mitigate the damage. Generally, long, hard training sessions don’t get you sick as much as they increase your chances of getting sick. With this in mind, you can stack the deck in your favor slightly. First, there’s the whole hygiene angle. Wash your hands more often. Avoid sick people, even if you’re married to them. Don’t lick foreign objects excessively. We all took health class in middle school. We all know the drill.

You can also fiddle with your diet—which brings us to the crux of this post. If you think I’m writing about avoiding illness out of the goodness of my heart, you’re sadly mistaken. The real reason I’m writing this is because I wanted an excuse to use the word “Immunonutrition.” C’est un bon mot, non? Perfect for cocktail parties because, unlike “nudiustertian,” it’s really easy to figure out what it means.

But I digress. There are a lot of tricky tricks you can try for boosting your temporarily depressed immune system. One pro tip is to supplement 250mg of baker’s yeast beta glucan post-workout. There’s some promising research showing it can shorten colds and increase your salivary IgA, which is a bacteria, virus, and toxin-fightin’ antibody found in your spit that’s somewhat protective when licking foreign objects.

But if you’re looking for the most bang for your immunonutrition buck, your two best bets are carb-feeding during your workout and fruit. Yeah, I know. Kind of boring. You were probably hoping I’d crap on about bovine colostrum or fish oil (both which show promise) but no, the killer chess moves here are boring things that 90% of us already do.

How they work is annoying simple. When it comes to carbs, hard training releases stress hormones like epinephrine and cortisol, both with cause inflammation and inhibit immune cells and proteins with fancy names like neutrophilia and interleukin-6 (which, coincidently, is the name of Adam Levine’s new band). Not feeding during a prolonged workout, especially when glycogen is running low, increases that stress hormone output. On the other hand, fueling properly reduces that stress. If you’re training for 2-3 hours, shoot for 30g-60g of carbs hourly from fluids and solids. If it’s longer training, you want to try for your upper tolerable limit up to 90g hourly.

As for fruit, again they’re loaded with good carbs, but they’re also packed with phytonutrients called  polyphenols that benefit athletes in a few ways. Exercise causes a lot of oxidative damage in the body—and polyphenols combat that. They can also combat inflammation and viral infection. Mix it all together and this means they help with post-workout soreness, acute illness, and chronic illness! Bargain!

On a final note, Although I wrote earlier that exercise doesn’t usually make you directly sick, sometimes it does. But next time a long ride, paddle, or run leaves you with a scratchy throat or a nagging cough, here’s something to consider. A 2007 study on 32 elite and 31 recreationally competitive triathletes and cyclists showed that the bulk of their post-training upper respiratory  issues weren’t infectious. In other words, they didn’t “catch” anything per se. They just ran themselves into the ground and needed to rest.

And they probably needed to avoid licking all foreign objects for a few days as well.