I found this interesting... and give credit to:
http://www.martinfrost.ws/htmlfiles/jan2007/handling_stress.html
STRESS ALTERS YOUR BLOOD CHEMISTRY
For years psychologists have concentrated on the behavioral symptoms of burnout: lost energy, lost enthusiasm and lost confidence. Now, thanks to new brain scans and more sophisticated blood tests, scientists can directly measure some of the effects of stress on mind and body--often with surprising results.
You are probably familiar with the signs of an adrenaline surge (racing pulse, hairs on the neck standing on end), which evolved to help us fight or flee predators and other immediate dangers. And you may have heard of cortisol, another stress hormone, which is produced more slowly than adrenaline and lingers in the bloodstream longer. But did you know that too little cortisol in your bloodstream can be just as bad as too much? Or that tucking into comfort foods, while soothing in the short term, can sabotage your long-term stress response by increasing the number of inflammatory proteins in your body?
What's emerging is a complex picture of the body's response to stress that involves several interrelated pathways. Scientists know the most about cortisol because until now that has been the easiest part to measure. "But when one thing changes, all the others change to some degree," says Bruce McEwen, a neuroendocrinologist at Rockefeller University who has spent decades studying the biology of stress, primarily in animals. So just because you see an imbalance in one area doesn't mean you understand why it is happening. "We're learning that post-traumatic stress disorder (PTSD), burnout, chronic fatigue syndrome and fibromyalgia are all related in some ways," McEwen says. The next step is to figure out if there are any genetic predispositions that tip the response to stress toward one set of symptoms or another.
I have found over the 18 some odd years that my children have been playing sports that by far, the most stressful time is when one of my children is the pitcher. Yesterday was no different as my youngest son took the mound in the MSU v. Rutgers-Newark game.