I read that a month or two ago. As is not uncommon with the NYT's reporting of sports medicine, the comments are more instructive than the actual article.

I know for a fact that in my body, both hunger and thirst shut down during hard exertion. I'd be surprised if it's different for most people - from an evolutionary standpoint, if we're trying to chase dinner, or being chased by something that wants to make us its dinner, we're not going to want to feel compelled to stick our faces in the watering hole, or climb a tree to pick fruit to eat.

I've made such a habit of drinking while running that I just know to do it. But during a very hard fast ride, or in the one triathlon I did last year in hot weather, I really have to force myself to drink. A friend of mine who's planning to finish his 100th marathon in a few weeks wound up in the medical tent twice this summer with heat exhaustion and dehydration because he's used to carrying his own water and couldn't drink effectively from the aid stations.

It's true you can avoid hyponatremia by not drinking, but to me that's like saying you can avoid blood sugar spikes by not eating. Your body needs water to cool and detoxify itself. If you're not getting enough sodium (or other electrolytes) the solution isn't to stop drinking water, it's to take in more sodium.

I might add that I consider myself quite in tune with my body. Medical professionals I've seen have confirmed that for me. I'm very aware of what muscle is doing what, and I'm starting to get a good sense for where mildly pinched nerves are coming from. I know when I'm hungry and what I'm hungry for (protein, calcium, B-vitamins, etc). Our bodies just don't send us the same messages during hard exertion that they do at rest, I don't believe.