Discussion: Can too much exercise make you sick?

There is an interesting article at www.active.com (back to our recent "Sickness & training" discussion):

http://www.active.com/story.cfm?story_id=11547

This is news? The authors seem to concede in the first paragraph that everybody already knows this:

"In fact, results from a survey conducted by the Gatorade Sports Science Institute show that nearly 90 percent of 2,700 high school and collegiate coaches and athletic trainers believe that overtraining can compromise the immune system and make athletes sick."

My experience agrees with the article. I get sick less when I'm active, but I've had problems training through illness. And when I overtrain or overcompete, I can exhaust my immune system.

The article particularly mentions people getting sick after the LA marathon. (Neglecting smog, I assume this is due to overexertion) Personally, the one time I remember getting sick from racing was the 24 hour Hood to Coast relay. So I'm curious how rogaines and similar events affect the body. In regard to duration, they are far more strenuous than a marathon. Can you train the body to handle this without the immune system crash?

I suspect Vlad had immune system weakness after a particularly strenuous Rogaine (where he was tied to Eric Bone to help him keep moving, despite very serious exhaustion.) He got some rare infection or something that doc's couldn't figure out easily that took a few months to shake off.

I doubt this immune system crash after 24 hour events is easily avoidable though. If you're in really good shape, you'll probably recover faster, but there will still be a period where your body is trashed. And in Vlad's case, he was in pretty good shape, but he just really, really pushed his limits...

I suspect that for races under 3 hours (e.g. marathons and shorter), well-trained athletes have little trouble at all. They are used to training an average of 2-3 hours per day and recovering from it within a day. So, for them, a week of World Cup orienteering races is, in terms of total volume, a rest week...

I was reading somewhere that they advised you to train for a marathon, but don't actually run it to avoid getting sick. The combination of a weakened immune system and running shoulder-to-shoulder with 100s of other germy people is a recipe for catching a cold.

With respect to the rogaines and the Hood-to-Coast, you have the physical effort and the sleep deprivation dragging you down.

too much training makes me sick of training.

That's right Eddie!!! Who needs all that training, when one can do well whithout , no need to worry about getting sick from training or of training.

Yeah. The viral vestibular neuronitis took me out for about 3 months and the left inner ear balance function, seemingly forever (currently guidance is provided by the redundant system on the other side). I don't think it was just the WRC that depressed the immune system, but rather the whole regime of doing an ultra a week.