It's somewhat common for runners to get sick during the taper phase right before their races, when stress and anxiety combine with a change in routine. I managed to stay healthy before both my fall marathons, but for the first time, suffered post-race flu!!!!! Gah it was awful!!!
The really weird thing is that my legs were aching! They felt worse with the flu than they did during and after the marathon. I can only assume it was caused by incredible dehydration.
So glad I don't have a race this weekend!!!!