Where we sweat a lot…
According to the Smithsonian Magazine I just read we all originated in Africa. The weather there a couple hundred thousand years ago was hot and humid. Somewhere our common ancestor slogged through a daily run in the hot and humid jungle. So you’d think we’d be used to it.
Unfortunately I think my more recent ancestors were digging in peat bogs somewhere in Northern Europe. I don’t perform well athletically in the heat. Neither does my Border Collie Buddy. Give us a couple inches of crusty snow and a driving sideways freezing rain and we’re right at home. Drop us into your standard Fourth of July race with full sun and 85 degrees and we wilt.
What can you do to mitigate the effects of the sun and the heat? First of all there’s no real reason we can’t have a good run on a hot day. Humans are designed to cope with the hot. Understanding the changes that your body goes through in response to the stress of heat will help you to come up with strategies to co-exist.
Failing a course of heat preconditioning I would recommend the following tactics to stay cooler.
1. Avoid the sun and heat as much as possible pre-race. Keep your core temp down. Stay in the shade until race time.
2. Don’t eat anything for a couple hours before the race. I’ve seen some gruesome finish lines from people who ‘fueled up’ before the hot race.
3. Manually rub/spray/squirt water on your large patches of exposed skin while you’re racing. I carry a water bottle and I’ll squirt water on my exposed arms and thighs in a race to maximize the evaporation potential over these large surface areas.
4. Get a good hat. Something light, light colored and vented. Lots of heat escapes through the top of your head – don’t trap it in.
5. Less clothing is better – maximize the surface area of skin exposed to the wind.
6. Lube up to prevent chaffing. When your clothing gets soaked with sweat it will rub more. Sweat becomes a whetting agent.
7. Help your body by visualizing. Picture the heat flowing from inside your core and out to the skin to be whisked away by evaporating water. Sounds hokey, but it helps.
What happens in your body when it’s hot out? Your body has a core operating temperature range that it likes to stay within. When you rev up the engine on a hot day through exercise your core temperature starts to rise and your body initiates response mechanisms to deal with it.
You start to sweat. Your body coats the available surface with a glistening sheen of water. Why? Because water has some amazing chemical properties (you may remember this from 8th grade science). Water evaporates. When it evaporates it changes chemical state from a liquid to a gas. This process requires a whole bunch of energy. It sucks this energy from the environment in the form of heat.
When you round that corner and feel that welcoming breeze in your local 5K you are feeling thousand of water molecules changing state and absorbing heat. Feels good doesn’t it? It’s the same concept as the radiator in your car.
Why is the radiator in your car so big? It is trying to present a large surface area to the wind to maximize the cooling. Your skin is your radiator. The more of it that you can expose to the wind the more efficient it is going to be at removing heat through evaporation.
As you continue to exercise your body starts to move more blood towards the radiator – your skin. The small capillaries in your skin will dilate to handle more fluid exchange – moving more blood away from your core and into your radiator. Your heart (the pump) will have to work harder to push this blood out to a larger surface area.
Ever feel nauseous in a hot race? That may be because your body has decided to reprioritize blood away from your non-essential core systems to get more out to the radiator. Our body thinks we must be being chased by a hungry lion and reprioritizes blood away from the GI tract and head to the muscles and skin. You become dizzy and sick to your stomach.
At some point systems start shutting down and if you tough it out long enough you can trigger a cascade of system failure that will end your racing career by putting you six-feet-under in a pine box.
So – What can a simple midpacker do about it? It really depends on how long you intend to be running. In longer races you’re going to need to focus on staying hydrated and getting the proper electrolyte balance, but the only real answer is to back off.
You can condition yourself to run in the heat by training in it. One of the hottest Boston Marathons on record was won by a furnace tender from Nashua N.H. who spent his working days shoveling coal into a blazing fire. All the other runners collapsed, but for him it was just another day at the office.
You may not have the option of shoveling coal every day, but you can take in some training runs in the heat and practice your water rubbing and heat exchange visualization. You may find that you enjoy working up a good sweat.
Be safe. Be careful. Unfortunately in our despoiled modern world many of the hot days also have bad air quality. Check the weather and use your head to stay cool.
See you out there,
C-,
Chris Russell lives and trains in suburban Massachusetts with his family and Border collie Buddy. Chris is the author of “The Mid-Packer’s Lament”, short stories on running, racing, and the human comedy of the mid-pack. Chris writes the Runnerati Blog at www.runnerati.com. Chris’ Podcast, RunRunLive is available on iTunes and at www.runrunlive.com. Chris also writes for CoolRunning.com (Active.com) and is a member of the Squannacook River Runners. ChrisRunner@runrunlive.com
Friday, July 4, 2008
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