"And was your hands frequently". This was the advice given to me by friends,who had kids, on how to minimize the risk of getting sick. I have to tell you, it totally works. I've gotten sick less since I've adopted this practice. As an endurance athlete I have to be even more careful. Studies have shown that after marathons, runner's have a compromised immune system and are susceptible to sickness. Well if it's true for marathons surely it must also be true for heavy training, triathlons and other activities that deplete the body. If 26 miles can depress your immune system, what about 50 miles, 100 kilometers or 100 miles.