the heat is on

I've had my fair share of meltdowns. And I mean physically melting. For some reason this summer has hit me harder than usual. I think it may come from the cumulative effect of several incidences in my past, including my bout with hyponatremia, and most recently, some heat sickness in Hawaii. Last week, hitting a new PR of sweating out 5 pounds in a 1:05 run, I think I became a little dehydrated and unable to adequately rehydrate. Runs in particular got worse and worse, until I was unable to go for more than about 25 minutes continuously. 

It has been hot, but I wouldn't say hotter than normal, and it's not like all this heat and humidity is new to me. So I've been doing a little reading to see what is normal and what is not. 

I've learned first of all that I am lucky to be as small as I am. I thought maybe having less surface area (especially with a stockier build) was inhibiting the heat from escaping. Apparently this isn't the case, as "smaller runners are still able to lose more heat relative to heat production than larger runners." Period. Well ok then, I'll lose a few pounds. Yet another reason. :)

At least I only have a slight chance of cooking my brain. Like the poor cheetahs that were run to heat exhaustion on a treadmill, humans tend to cease all activity at a body temp of 40C as well. This is regardless of heat adaptation, the rate of heat storage, pre-run cooling, and any external "intervention." And not only that, your central governor (remember that one?) will cause an anticipatory regulation of pacing so that if it feels you are increasing your temperature too quickly, it slows you down. I think this is what is going on with me. But for some reason it doesn't switch on until 25 minutes into my run... need to get that switch checked out.

So you wonder if my previous dehydration causes any of this core temperature rise? It seems it doesn't. (It's metabolic rate.) I'm still not sure exactly what to do about all of this. I think a move to the desert may be the solution (hooray! that's what I'm doing!). There's so much more information  about all this at sportsscientists.com, one of my favorite websites. So if you suffer like I do, check out their series on fatigue and heat.

Until New Mexico!