Sunday, October 11, 2009

Cold Weather Hydration

Its oddly deceptive. You go for a run or walk in the cold and figure you're not going to sweat as much and so that means you don't have to consume as much liquid.


In fact, it may come as a surprise to find out that you may need even more water during colder climates.

Before we continue with this train of thought, lets talk about what water, which makes up 60 to 80 percent of your body, does that is so important. In the blood, water helps transport nutrients, oxygen, glycogen and more to the cells, all of which are used to produce energy and keep the cells running efficiently. It then carries waste products away from the cells. In sweat, it is the evaporation process which helps the body to cool its surface which in turn cools the blood which lowers the overall body temperature.

Why is this important? Without the essentials for energy production eventually your body will stop operating. Without the removal of waste products, your body will slowly poison itself. If your body temperature rises over a high of about 106 degrees Fahrenheit, your cells will actually begin to cook themselves.

Needless to say these are just a few of the reasons we need water in our bodies and yet alone each one should be motivation enough to keep hydrated.

Something you might not think about, lower temperatures “inspire” urination. That means a greater amount of your consumed liquids are passing directly through your body without the opportunity to be absorbed.

It’s a fine line you run in the cold! During a cold weather run or walk you face two different problems. Overheating (too hot) and hypothermia (too cold). You will walk a thin line from your first step. Initially, you will experience the cold. Generally this initial cold is not much more than a distraction as your body begins to heat up and acclimate to the lower temperatures.

The next phase is overheating due to lack of sweat evaporation. In cold climates sweat which is designed to cool the skins surface by vaporizing takes longer to do just that than it does at warm temps; That pooling of sweat initially causes your body temperature to rise abnormally as it is trapped under layers of clothing.

As the clothing gets saturated with moisture the problem quickly turns in a different direction… too much cold! All of this cold begins to drop the temperature of the skin surface extremely fast. As you are likely dehydrated at this time all of your functions begin to slow down. Dehydrated cells deliver less of the fuel needed for energy production and at a slower rate which in turn means less energy production and ultimately less heat, a by product of energy creation. As your body continues to drop you experience hypothermia and a shutdown of your bodily functions. This is why often when you hear of victims of cold weather accidents they are both dehydrated and hypothermic.

All of this to come back to… how to stay hydrated and safe in cold weather. Although you may not feel like it, you need to approach cold weather hydration in the same manner that you do hot weather hydration. Experts recommend approximately 6 oz. of cool water 30 minutes to exercise and then 4 to 6 oz. every 20-30 minutes.

As with warm weather exercise you need to drink before you’re thirsty. The sensation of thirst is triggered when your body senses a concentration of certain elements (such as sodium) in your body. When this occurs, you are already at least mildly dehydrated and if you haven’t been taking in fluids it can lead to serious consequences.

Want to get more exacting on how much fluid you need to take in? Try this simple method for determining how much water you lose during exercise.

Since most weight lost during exercise is directly attributed to sweating weighing yourself before and after an exercise bout will tell you how much water you are loosing.

Let’s say you run for an hour and lose 2 pounds of bodyweight. That two pounds represents 32 oz. What this tells you is that you should be consuming 16 oz of fluid every 30 minutes. That number may be a little high but everyone is different. Some sweat more, some less. This method will give you the most accurate answer to how much to hydrate.

Yesterday, I ran in temps near the upper 40’s plus a windchill. It was cool. I never really felt myself get warmed up and as such I couldn’t really tell if I was sweating. I stopped for a minute a the trailhead of a route I had never run and the sweat came dripping down in great big drops. It was a classic case of what happens when running in the cold. The sweat continues at it regular rate but instead of evaporating as it would in warmer temps, it pools on the surface of your skin. If I hadn’t been taking in fluids, I would have found myself dehydrated in spite of the fact that I couldn’t feel it.

If your runs aren’t going as well as you think they should while its cold out it could be that you’re a little dehydrated. Increase the fluids and you may just find your cold weather training going to a whole new level.