My first half-marathon was nothing like I expected it to be.
My finishing time was about right - 1:51:33. But I didn't think on that late spring Sunday last year that the temperature would be in the mid-70s by the time the race started. I didn't plan on the sun beating down on me for nearly two hours.
And I certainly hadn't counted on nearly dying that night, ending up in the intensive care unit of the hospital with severe overhydration.
I knew about overhydration - or hyponatremia - having read about a woman who collapsed and died during the Boston Marathon a few years earlier. My mistake was that I didn't push myself harder to replace the salt I had sweat off during the race, and I wasn't able to recognize when it was becoming a serious situation.
The condition is a real threat, said David Bernhardt, medical director for the Madison Marathon and a sports medicine physician at the University of Wisconsin. A 2005 study published in the New England Journal of Medicine showed that among 488 Boston Marathon runners who provided blood samples at the end of the 2002 race, 13 percent had hyponatremia, while 0.6 percent had critical hyponatremia.
But the threat of not consuming enough fluids is just as real as overhydrating and depleting the body's sodium levels, which is why physicians urge caution in either direction. My concern that morning last May was that I would be dehydrated; during one of my long runs a few weeks earlier, I hadn't had enough water to drink and felt sick the rest of the day.
So, I drank some water and Gatorade in the car before sidling up to the starting line of the Madison Half-Marathon, but was careful not to overdo it.
"One of the problems with some people is they overdo it so much before the race that they dilute themselves," said physician Bob Murray, director of the Gatorade Sports Science Institute in Barrington, Ill.
My colleague, Tom Held, is a more experienced distance runner who also ran the half-marathon that day, and he had a greater sense of how much the weather could affect the race.
"This could be trouble," he told me he remembers thinking.
I started strong, feeling loose as I knocked off the first few miles ahead of my expected pace. This was my first race longer than an 8K, and running a half-marathon was something I'd toyed with for a few years, with my sights on a full marathon someday.
Because I was worried about being dehydrated, I grabbed water at most, if not all, the water stations every couple of miles - and took Gatorade when it was offered. Still cruising along past Camp Randall Stadium halfway through, I waved happily to my husband, Colin, and friend Jenny who came out to cheer me on. I downed a packet of Gu, an energy gel, about an hour into the race for a boost.
All the way, it just got hotter. The heat caught up with me, and I slowed down a bit. I crossed the finish line with one last burst of speed but was happy to get my tired feet off the blazing asphalt - and eagerly took the bottle of water handed to me moments later.
I saw Tom just past the finish line, and he remembers me looking normal. In retrospect, Colin remembers that I looked overly sweaty, but even that wouldn't have necessarily been a red flag. Through years of soccer games and track meets, I've always looked red-faced and sweaty by the time I'm done.
Stepping into line to get some post-race food, my calves started to cramp. I chugged the water to try to alleviate the cramping. My stomach started to feel a little queasy as I tried to eat a banana and a bagel. It was tough to get any food down.
I had some water at the diner where we ate brunch and drank some Gatorade in the car on the way home. Soon I was vomiting. I sat in our bathtub for a half an hour, sipping water, but still couldn't cool down.
Around that time, Bernhardt was closing the full marathon course, an unusual call.
"Many people - you included - were not acclimated to the heat and your body hadn't really adjusted," Bernhardt told me, adding that the longer someone is running, the more risk there is for developing dehydration or overhydration.
As the afternoon wore on, I kept feeling worse instead of better. A headache settled in, and I couldn't shake my queasiness. Colin checked online for information on how to treat dehydration, but we also discussed whether I was overhydrated. Symptoms for both were similar.
My headache should have been a trigger for us to go to the hospital, Murray said.
"That's always a sign, but it's going to be impossible to tell whether you're suffering from severe dehydration or overhydration," Murray said. "In any case, the best thing to do is to go to the emergency room and have them take a blood sodium level" to decide what treatment is best.
At about 8 p.m., I called a nurse. She told me to get into a cold shower and to start drinking Gatorade, which can replace the body's electrolytes and sodium that are lost with sweating.
I was feeling really out of it, and that's when I told Colin I thought we should go to the emergency room.
I trudged in to Meriter Hospital just before 10 p.m. Soon, I was in a bed with an IV, trying to answer the doctor's questions. Colin tried talking with me, but I knew I wasn't making very much sense. "I'm really confused," I finally said. That's the last thing I remember.
I have almost no memory of what happened over the next 32 hours. From what Colin has told me, I had seizures for about a half an hour, and he helped the doctors and nurses hold me down. My medical records show my sodium level was at 117, sharply down from a normal level of about 140; the benchmark for critical hyponatremia is 120. The doctors whisked me out of the ER for a CAT scan because they thought the pressure on my skull might require brain surgery.
That wasn't necessary, but it was still dangerous as my doctors worked to slowly raise my sodium level. Finally, by Tuesday morning, it was back in a safer range, and my doctors took me out of sedation.
Murray said my story is unusual for a number of reasons. I have a high sweat rate, meaning dehydration is more likely to be my problem. I also didn't overdo it by drinking water excessively the night before or during the race.
Now, I'm just a casual runner again - a half hour on Saturday afternoons - and very lucky to be jogging at all.