pre-race review

Last week when I spoke about race preparation I got a few funny looks when talking about calculating hydration and calorie needs for racing. So I thought I would review a few easy tools to ensure that you have a good race this fall, when weather can be very hot or quite cool.

Performing  a water loss calculation as part of your homework about yourself is easy to do with a bathroom scale. Pre-run, weigh yourself naked. Post-run weigh yourself again and compare the values. Any pound of weight change multiplied by 16oz equals the amount of water lost during your run and you should drink the corresponding amount of water to replace your loss. On future long runs you can seek to drink some of this fluid as you are losing it by sipping every 15minutes. During hot days and heavy sweating most folks need 16-32oz per hour of exercise or 3-6oz every 15-20 minutes. (If you gain weight during your run, you are drinking too much water – this is tough to do and somewhat self-limiting due to sloshing or GI distress, but read the hyponatremia article posted below)

During longer runs you may want to think about eating simple foods to keep calories on board and avoid bonk. Runs over one hour fit into this “long run” category. Runners traveling over an hour need 240Kal/hour to avoid bonk. If you try to eat – use simple, low fiber, no dairy foods and document what agrees with you. The maximum you’ll be able to use is 240-280Kal/hr so you are not replacing everything – just trying to maintain homeostasis. Examples to try include: Energy gels, Bananas, Fruit chews, PBJ sandwich on wheat, Gatorade, Pretzels, Chia seeds etc. and you’ll notice that I use a lot of real foods because of price and nutrient density. See what works for you.  There are 4 Kal/Gram of carbohydrates, so you can work with ingredient panels on your food to estimate what you are getting before you try it.

Here is a simple chart for those of you who do not have a bathroom scale or possibly do not wish to remove those sweaty clothes and get weighed. Read this by body weight and you’ll see an amount of fluid (in ounces) following each temperature range (in degrees Fahrenheit).  So you might estimate this way how much liquid you’ll need per mile. For example I am 155 on race day and if the temperature is 70 degrees, I might need 5.3 ounces/mile of running to stay mostly topped off, without sloshing. How would I know this works? If you said “test it first on a long run” you win the prize. This chart is just an estimating tool and I got it here. http://www.runnersworld.com/article/0,7120,s6-242-302--10084-2-1-2,00.html

Weight 100
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 3.0 60°F: 3.2 70°F: 3.3 80°F: 3.6 90°F: 4.1 100°F: 4.7

Weight 120
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 3.6 60°F: 3.8 70°F: 4.0 80°F: 4.3 90°F: 4.9 100°F: 5.6

Weight 140
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 4.2 60°F: 4.4 70°F: 4.6 80°F: 5.0 90°F: 5.7 100°F: 6.5

Weight 160
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 4.8 60°F: 5.0 70°F: 5.3 80°F: 5.8 90°F: 6.5 100°F: 7.4

Weight 180
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 5.4 60°F: 5.7 70°F: 5.9 80°F: 6.5 90°F: 7.3 100°F: 8.4

Weight 200
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 6.0 60°F: 6.3 70°F: 6.6 80°F: 7.2 90°F: 8.1 100°F: 9.3

Weight 220
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 6.6 60°F: 6.9 70°F: 7.3 80°F: 7.9 90°F: 8.9 100°F: 10.2

Weight 240
Fluid Ounces Per Mile Depending On The Temperature: 50°F: 7.2 60°F: 7.6 70°F: 7.9 80°F: 8.6 90°F: 9.7 100°F: 11.2