Tuesday, June 1, 2010

Lessons Learned

After my flirtation with dehydration last weekend, I have been researching summer running strategies.

I read from several sources that runners should strive to limit their weight loss due to dehydration during a workout to no more than 2% of their total body weight.  For me that means 3 to 4 pounds. I have long been in the habit of weighing myself before and after each run and have noticed weight fluctuations of nearly twice that amount after weekend long runs. It’s obvious that I need to significantly increase my fluid intake.

Equally important is the replacement of electrolytes, particularly salt, during long runs. I believe that it was a deficit of electrolytes that caused me to bonk during what should have been an easy run for me last week. In a worst case scenario, hydrating solely with water can result in a condition called hyponatremia, a dilution of electrolytes in the body, that has caused deaths during marathons.

I applied these lessons to a 19 mile run I ran on Saturday in temperatures ranging from 71 to 80 degrees. Over the course of the 3 ½ hour run I consumed 82 ounces of fluids. I also inverted the ratio of Gatorade and water that I usually consume. Over the past few months I have been either drinking water alone or a combination of about 75% water and 25% Gatorade. This week it was 75% Gatorade and 25% water.

The result was a successful run completed without any walking. While I was tired at the end of the run, it was not even close to the exhaustion I felt after only 10 miles last week. I lost about 3 pounds, right on target with the 2% goal, and I only suffered some of the more minor symptoms of dehydration. While the volume of fluids was right on target, I think I will be able to cut back a little on the amount of Gatorade. Towards the end of the run it started to feel like I was drinking syrup. I also intend to check out other sources for electrolytes besides a sports drink.  I recently read a good recommendation for NUUN tablets over on the cool running forums.

It will take some experimentation to perfect these hydration strategies, but I think they will safely get me through the summer running season.


  1. I feel like I have been asking this a lot lately, but what did you use to carry the water/gatorade in? Camelback or Nathan belt (or something like that?) Or did you just loop back to your house to get more?


  2. Hi Cristina

    I use a Nathan water belt with 22 oz. bottle. I was running a 5 mile loop around my neighborhood and refilled when I passed my home. I like the belt but it does cut into my side on really long runs if I wear it under my shirt and I need to do that because I constantly use my shirt to mop sweat off my face.

    I bought a Nathan Quickdraw Elite handheld water bottle and tried it for the first time on an 8 mile run yesterday. I will have to use it a few more times to see if like it.