June 18, 2012

Too Hot to Handle: Heat Management

Now that the summer is upon us, is it getting a bit too hot to handle on long rides? When the temps start creeping up, it's not enough to just chug a few more liters of water along the way. It's important to embrace early-morning activity and rely on technology or tricks to keep your body temperature from overheating.

So how do you help your body's natural air conditioner, especially if it's on the fritz? From the wannabe Slurpee to the plain silly, try some of the heat management tactics below. And since I haven't tried them all, please let me know if it's a cooling success or spectacular failure....

Your body is about 98.6 degrees, meaning there's not much more heat needed to hit the possible danger zone of 103. But the body is a pretty efficient air conditioner, cooling itself by pumping blood close to the skin, pushing sweat out of glands, and allowing the resulting evaporation to regulate the body's temperature. That's why humans can exercise longer than animals; our endurance is linked to our ability to cool through sweating...unlike say, your dog, who without sweat glands has to stop and pant at every stoplight. Of course, in our east coast humidity, the body's cooling system has more difficulty; the humidity and moisture in the air makes evaporation harder and makes your temperature harder to regulate (unlike the dry heat in the southwest, which readily pulls moisture right off your skin).

Hot trip to Death Valley last week!

Hydrate and Train in the Heat
Drink water and use insulated bottles. Tell us something we don't know.
Get used to the heat. Another duh! comment.

Throughout the summer, but especially in times where you'll be experiencing increased activity, it's important to stay hydrated all day (not just before a ride). Before hard days, be sure to eat salty foods to enhance body fluid retention and drink a couple hours before hitting the pillow, as your body can dehydrate significantly over eight hours of sleep. And use insulated bottles while riding, especially if pouring them over your helmet and jersey on occasion.

After many months of cool weather, it can take a week or two for your body to become accustomed to physical exertion in the heat. During this time, it's best to take it a little slower, drink more, and pay attention to your body's warning signs. Acclimatization also changes your body itself...you know, all that scientific stuff like blood plasma volume expansion, decrease in heart rate, and all the other efficiencies documented in my prior posting of a Washington Post infographic.

Douse Yourself
Probably obvious, but as evaporation from sweat cools your body, so does water on your skin, and water is 20-40 times more conductive than air alone. That's why even with cutting edge cool-fabric technology on the market, Colorado River guides wear 100% cotton, even though they're spending two weeks on the water in 100+ temperatures. When cotton gets wet, it sticks to your body and the subsequent evaporation cools you down; so the river guides just frequently dunk their hat and shirt in the water. Similarly, on my expedition through the southwest last week, we were dunking our hats in every mountain creek we could find. Your preference on riding gear aside, you may not want to use cotton (and in running, spare your nipples, men), but it doesn't hurt to hit your helmet and jersey with a squirt from your water bottle once in a while, even if nylon isn't as effective as cotton in this case. And as long as it doesn't impact your safety or ability to grip the drops, wet your cycling gloves while you're at it.

Enjoy a "Slurpee"
I guess I don't necessarily need to put Slurpee in quotation marks, since I know some folks who actually perform this trick with a legit Slurpee from 7-Eleven. But that's just a bit too sweet for me; not to mention I'd have to ride my bike to the store to pick one up, completely negating the idea of pre-ride cooling explained below.

About an hour before your ride, down a "slushee" made by putting the following in your blender:
  • 1 cup ice
  • 1 cup water
  • 0.25 cup sports drink (I prefer organic fruit juice with pinch of sea salt)
This will lower your body's internal body temp much more effectively than cold water alone. By starting with a lower core body temperature, you give yourself a buffer and can go longer before your body heats up to the point where your brain says "WTF?" and sends out the distress signals.

Ice Socks
On a recent time trial on television, the commentators noted a hunchback racer who was taking full advantage of "ice sock technology"...a pair of pantyhose swiped from an equipment manager's wife and stuffed with ice. But per a VeloNews Q&A, stockings work better than pantyhose (hell if I know the technical differences there). Either way, the concept remains the same.

Back pouch ready for an ice sock.
(image from Bicycling magazine)
Take 6-10 inch sections of hosiery, stuff them full of ice, and tie off the ends. Put a few of these in the freezer overnight and before your ride, put one up the back of your jersey. It will keep your back cool with direct cold and as it melts it will also aid in evaporation cooling. Obviously, you'll need a tight fit on your jersey if you don't want your ice sock to become an ice tail...as that's just not flattering on anyone.

Other non-hosiery options include filling a knee-high tube sock with ice and draping it over your neck. Or even easier, I often freeze a disposable water bottle and insert it in the middle back pocket of my jersey. It keeps me cool for a while, and once it starts melting too much, I pour the cold water over my helmet and jersey while on the move.

Garmin's Castelli-brand skinsuits have a pouch in the back of the jersey for a radio transmitter. But it's also used for socks stuffed with ice during particularly hot time trials.

As with any other billion-dollar industry, technology exists for everything, and the heat is no exception. I won't go into the products here, but you can find hundreds of options on Google and Amazon for cooling vests to wear before and during activity, "cold tech" biking jerseys and running shirts, and bandanas and ball caps with ice compartments.

Uh...good luck with that.