When I was in 8th grade, I went to a sports camp in the summer – working out hard every day in the heat. The next week I got sick. I remember everyone saying: “You pushed your body too hard!”

Ever hear that too?

We used to think that hard exercise suppressed our immune system. We used to think doing things like running a marathon would make us more likely to get sick.

That’s actually not the case at all!

Here’s what’s actually happening: There are fewer immune cells floating around in your blood for about two hours after a hard effort.

So, for a long time, doctors and researchers thought that this means our immune system was weakened after exercise.

But, those immune cells are actually going out into other places in your body!

After exercise, immune cells go out and look for pathogens. They go to places where immune cells don’t normally reach that often.

That’s according to a recent study published in Frontiers in Immunology that’s turning the myth of a suppressed immune system after exercise upside down.

Guess what else researchers found? The harder you go, the more immune boosting benefit you get! This helps explain why frequent exercise helps hold off chronic disease as we get older (plus less risk of viral and bacterial infection too!).

So, turn up the burn with short, intense workouts! The harder you go, the better!

P.S. The reason people are more likely to get sick after running a marathon? It's actually because of how many people they are around...not the exercise effort.