On the Verge of a Bonk

Knowing a lot about something doesn't make you smart, or even an expert. I've been walking for exercise for nearly 6 years now, and I've learned a great deal about all things walking. Including, I thought, how to prepare for walking in hot and/or humid weather. Apparently, I've either forgotten everything I knew, or I've chosen to ignore it.

On today's calendar according to my half-marathon training schedule was an 8 mile walk. I've been doing a lot better about keeping to a 20 miles per week walking routine, but 8 miles is the longest I've done in a while. But after a 6 mile walk 2 weeks ago, and four 20 mile weeks in a row, I figured I was ready. And I would have been, except for one small detail: the weather. Here in North Carolina, summers are typically hot and humid. I walk in the mornings, when the heat is much less of a factor but the humidity most definitely is. When I stepped outside this morning at about 6:15, temps were in the low 70s, the sky was overcast, and the humidity smacked me in the face as soon as I opened the front door. I'd say it was definitely over 75%. Ugh. My mouth was a little dry when I woke up, so I took a few sips of water before I left. Somehow, it didn't occur to me to bring any water with me. Big mistake.

I know all the things I'm supposed to do when I walk during the summer. Wear a hat (check), wear light-colored clothing (check) - preferably moisture wicking (check) - and stay hydrated (um, no check). But I also know from past experience what my body can tolerate, and how far I can walk before I need to drink and eat. I've done plenty of 8 mile walks before while training for other half-marathons, and I almost never bring water or food with me. If I'm walking more than 8 miles, then yes, I'll bring things along. But for me, 8 miles is the cutoff when it's not necessary to worry about hydration. Or so I thought.

The walk started off well enough, and the cloudy skies helped keep the temperatures to a reasonable level. By the time I hit the 4 mile mark, though, I knew I was feeling both the miles and the humidity. I was thirsty already, and no water was in my future. Not only didn't I have any with me, but I had failed to bring along a dollar or two for just such an emergency. After 5 miles, I was sweating profusely (even more than usual, as I tend to sweat more than the average person), and getting more and more thirsty. I was also starting to feel "the vapors." You know that feeling you get when you're kind of woozy, you're starting to weave a little bit, and your mind wanders? Yep, the vapors. Athletes talk about the bonk: the point at which your body rebels, your energy reserves are on empty, and you've got almost nothing left. I was on the verge of a bonk, and I knew it. Somehow, though, I pushed through it, and finally made my way home without too much damage, although I was sweaty from head to toe - so much so, in fact, that sweat was dripping off the bill of the cap I was wearing. I immediately sucked down 16 ounces of water, and have been drinking on and off since then.

So where did I go wrong? I think there are 2 main mistakes I made. The first was underestimating the effect that the high humidity would have. Yes, the temperatures weren't bad, and the sun wasn't beating down on me. But when it's that muggy out, I sweat a lot more. I needed to replace the large amounts of fluids I was sweating out, and I couldn't do that. The second mistake I made was overestimating my fitness level. Yes, I know how my body has responded in the past, but the reality is that I'm not in as good a shape as I used to be. I've gained weight over the past year, and I haven't walked nearly as many miles as I did last year. The combination of both of those things means that I can't trust past experience when I'm making decisions about whether to carry water with me.

It's an embarrassing mistake to make, especially for someone who walks a fair amount. I was imagining all sort of scenarios, including passing out, and wondering how I would explain how I got to that point. Fortunately, the worst case scenarios never came to pass. I did learn my lesson, though, and if the weather conditions are similar for my next 8 mile walk, I'll be toting along some water. Better safe than sorry is something I thought I already knew, but it seems like I needed a reminder. I sure got one.