Member Question: Run Hydration and Nutrition for Ironman Louisville

author : mrakes1
comments : 0

On long runs, I've been taking 4-oz of Gatorade Endurance every 10-minutes, for a total of about 24-oz an hour. Should I boost my liquid consumption on the runs?

Member Question from g_schotts


"I'm training for my first IM - Ironman Louisville and have managed to really confuse myself over hydration quantities. I expect the race to be hot and humid, which matches my training environment in southeast Texas. I did a sweat rate test yesterday during a long run. Results are below:

Initial Wt: 184.0
Final Rate: 176.5
Consumption: 70 oz of GE
Total Loss: 156 oz
Duration: 2hr 20 min

Conditions were hot (low 90's) and humid. I calculated my sweat rate at 67-oz per hour. I've read that most people will be unable to process much more than 30-oz per hour, but that to keep from dehydrating, you should try to have no more than a 3% drop is weight. Those two factors don't add up for me. Based on my sweat rate, it there a good starting point for me to use in planning race-day hydration? On long runs, I've been taking 4-oz of Gatorade Endurance every 10-minutes, for a total of about 24-oz an hour. Should I boost my liquid consumption on the runs? If so, how much?"

Answer:

Athletes often listen to their bodies when fueling during workouts. If you feel thirsty, you drink. If you feel hungry, you eat. However, in an Ironman race, it is easy to lose track of time as the minutes become miles and before you know it, you “forgot” to drink for the past 30 minutes. Drinking every 4-6 ounces every mile on the run, or every 15-20 minutes on the bike, is a perfect strategy to meet fluid and caloric requirements during an Ironman. Especially in a race such as IMKY, where you are likely to feel the heat and humidity during all 140.6 miles of the course, it is important that your body properly digests calories as you attempt to meet hydration needs. Because running requires most (if not all) major muscle groups, you may find that drinking 20-24 ounces over a course of an hour of the run is more tolerable to the stomach compared to drinking 24-28 ounces an hour on the bike. Avoid over-drinking during the course of the race, especially during the run.


After the first 1.5 - 2 miles of the run, avoid drinking/eating in order to establish a steady gait and to prepare the stomach for 26.2 miles of weight-bearing exercise. Plan to grab a sport drink (generally Gatorade Endurance) at every aid station. Because you do not want over-concentrated glucose/fructose-containing drinks sitting undigested in the stomach, keep your fluid intake to 1/2-2/3rd cup of sport drink at every aid station (3-4 ounces). After you take a sip of your sport drink, to provide your body with calories, grab a cup of water for additional cooling on the body and to splash out the mouth. In order to meet the caloric needs on the run, it is recommended to consume 1 gel every 40-50 minutes at the aid station, rather than a sport drink, and to consume 4-5 ounces of water with that gel.
 

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date: August 26, 2009

mrakes1

Master of Science degree in Exercise Physiology. I am a certified sports nutritionist through the International Society of Sports Nutrition,I teach spinning and I am CPR certified. I have finished the 2006 Boston marathon, 2006 IMFL, 2007 Ironman world Championship and I am qualified for the 2007 Ironman 70.3 World Championship. I write for Triathlete magazine and I love writing for BT.com!

avatarmrakes1

Master of Science degree in Exercise Physiology. I am a certified sports nutritionist through the International Society of Sports Nutrition,I teach spinning and I am CPR certified. I have finished the 2006 Boston marathon, 2006 IMFL, 2007 Ironman world Championship and I am qualified for the 2007 Ironman 70.3 World Championship. I write for Triathlete magazine and I love writing for BT.com!

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