Tuesday, January 5, 2010

Keeping Warm Skiing and Snowboarding

We had a great holiday week at Seven Springs. It was amazing winter weather...most people wouldn't describe it as good winter weather...but amazing just the same. It was cold, snowy and blowy - the likes we haven't seen in years. Not over the holiday break anyway.

Somehow, since it has been so long since we have had a long period of such blustery weather, people seemed to have forgotten how to dress for it. I can't tell you how many frozen people came stumbling into the shop hoping to find some piece of magic to keep them warm. No offence but it isn't magic...just physics.

The human body is an amazing furnace and will produce more than enough heat to keep the average person comfortable - the trick is to save that heat and keep it close to your body. Heat is drawn away from your body by low temperatures (most people get that one), wind (we all recognize windchill) and moisture (not everyone gets that one so we'll talk about that later). The trick to keeping cozy is to stop those elements from robbing your body of the heat it has produced.

Layering is the biggest trick for combating low temperatures. The key is to layer effectively. I can not tell you how many of the people who came in from the slopes this week complaining of the cold had layered with cotton...their layers consisted of a cotton T-shirt, often a short sleeved t-shirt at that, and a bulky hoody under their jacket and honestly believed that they would be warm in sub-freezing temperatures.

Three fatal errors here. 1) Cotton has no thermal capacity - We wear cotton in the summer to dissipate heat. 2)Cotton holds moisture that will rob your body of heat and 3) Bulky garments cause constriction that reduce blood flow and pockets of air that are too big to warm effectively.

So if you are one of the hoody-clad, cotton-wearing masses you may be trying to defend yourself right now..."I was never cold before," "I always wear my sweatshirts to class and I'm fine"...I've heard it all before. This is physics, I'm sure you 'felt' cozy but that is different than being 'warm'.

The fact of the matter is that cotton simply does not have the fiber structure or material content to retain heat. It doesn't, there is no thermal quality to cotton - end of story. Cotton does, however, retain moisture, and a lot of it. Not only does cotton absorb moisture it is exposed to - it holds on to it. The bulkier the cotton garment is the more moisture it will hold - think of how long it takes for your hoody to dry in the dryer versus a thin pair of boxer shorts. If you are layering with cotton all of the sweat is absorbed by that cotton and held there near your body, robbing your body of precious heat. You will be at least 30% colder when you are wet - think of how cold you are when you get out of the shower-you dry off and you are warmer. In this shower example the temperature of the room didn't change, you didn't change what you were wearing...just wet, then dry, cold, then warm. If this example is lost on you try it next time you shower.

Some people have tried to argue with me that they don't really sweat, or that they only sweat when they are over heated...um, hate to break it to you, we all sweat and we sweat a lot. The average person sweats anywhere from .5 to 1.7 liters an hour depending on activity level. Skiing and snowboarding rank quite high on the activity charts so to help you with the visual try this exercise for yourself - take that cotton hoody you think is so warm, take one of those typical bottles of 'Natural Spring Water' you have sitting at your desk and dump it on your sweatshirt - then put it on and tell me how warm you are...cozy, right? The next problem is that it doesn't dry very fast - and each hour you have to dump another bottle of water on it. Not dry, not warm, not cozy.

Now the fact that most hoodies don't fit comfortably under your typical ski or snowboard jacket seems like it might be a giveaway for some people...none-the-less I see people do it all the time. Hoody hoods stick out and collect snow or even better, are crammed into the jacket making the wearer look like the Hunch Back of Notre Dame. Rolled up sleeves often stick out past the jacket cuffs and the hoody hem and extra fabric bunches all out under the bottom of the jacket...It is quiet the fashion statement-but beyond that it has created pockets of dead air that the body simply cannot warm up. The idea behind layering is to create small pockets of air that are easy for the body to warm up creating a buffer zone of warm air that protects you from the cold elements. Each of these layers holds heat long enough for you to produce more - it helps you keep ahead of the power curve. Sure heat is lost to the elements but it is done at such a rate that you can produce enough to replace what is lost so as to keep you warm. Large, open pockets of air can't do this.

In addition, those bulky garments will constrict in other areas often reducing blood flow causing certain areas of your body to be cold. One of the best examples of this is the big open sleeve of a hoody crammed into the sleeve of a ski or snowboard jacket. Typically the hoody will bunch up at the upper part of the sleeve, particularly on the inside of the arm, closest to the body. This just happens to be the place where the major artery to your lower arm happens to be and any pressure on that artery will reduce the blood flow to the hands enough to freeze those little fingers to the bone faster than you can say "Does this run take me back to the lodge?"

So now that I have let the cat out of the bag, yes, the ultimate warmth of your fingers, and your toes for that matter, is directly related to what you wear on your body. I'm not talking about just the artery deal - I'm talking about the whole layering-and-keeping-your-body-warm deal. Keep in mind that in a survival situation your body thinks of your fingers and toes as expendable. Your body doesn't realize that you have chosen to go out in sub-freezing temperatures and expose yourself to the adrenaline rush of skiing and snowboarding to have a little fun - it thinks this is serious business and unless your core body is warm it will not, I repeat, will not allow one ounce of extra warmth to head to the fingers or the toes. Blood flow will be restricted to the rest of the body and saved for the head and the core of the body until such time that it feels there is heat to be spared. So while good gloves are important, your body layers are even more so.

So please, no cotton layers, no jeans, no sweat pants, no hoodies, no gym socks-you'll freeze and then I'll feel bad because I'm the one who is supposed to make sure you are warm so you can have fun.

Keep warm so I can see ya on the slopes!

Kjerstin

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