I have been doing some testing of the amount of water/weight i lose given a certain pace and time. Right now, I am losing about 4 pounds per hour at 7:00 pace. This is without drinking any liquids during this time. With this data, can anyone tell me about how much fluids i should be drinking for a 3 hour marathon? Am I to drink 4 pounds of water/gatorade each hour?
I have been doing some testing of the amount of water/weight i lose given a certain pace and time. Right now, I am losing about 4 pounds per hour at 7:00 pace. This is without drinking any liquids during this time. With this data, can anyone tell me about how much fluids i should be drinking for a 3 hour marathon? Am I to drink 4 pounds of water/gatorade each hour?
General rule of thumb is that every one lb weight loss represents ~16 oz of fluid. This would suggest 64 oz/hour to completely offset fluid losses.
Unfortunately, this is probably beyond the capacity of your stomach to absorb fluids during a run. You might make half of that or 32 oz. It will delay, but not eliminate dehydration during the race. You will need to practice drinking on the run prior to the marathon.
Note: dilute carb-solutions (about 57% or 30-60 grams/32 oz fluid) improve the body's ability to absorb fluid from the gut and help to delay a drop in blood glucose (and spare glycogen). You should also practice that prior to the race.
I have been doing some testing of the amount of water/weight i lose given a certain pace and time. Right now, I am losing about 4 pounds per hour at 7:00 pace. This is without drinking any liquids during this time. With this data, can anyone tell me about how much fluids i should be drinking for a 3 hour marathon? Am I to drink 4 pounds of water/gatorade each hour?
Confused in Cleveland
Your baseline fluid needs when you’re not training are about 64 ounces per day. On top of that, you need to add your fluid losses from training and other activities. Becoming fully hydrated typically requires drinking an amount of fluid equivalent to about 1½ times the amount of weight that you lost. Replacement drinks with 4 to 8 percent carbohydrates. The carbohydrates can help your performance during workouts lasting longer than 1 hour. The concentration depends on your tolerance and how warm it is.
Can you take in enough fluid during a long run or marathon to prevent dehydration? You can postpone its impact by hyrdrating before the run and during the run by teaching your body to maximize its absorption capabilites.
Fluid Loss: Cool day – 2 to 3 pounds of water per hour Warm day – 3 to 4 pounds Hot day (above 80 degrees) – 5 pounds per hour A typical runner can absorb 28 ounces per hour (a little less than 2 pounds). Therefore, on warm or hot days, you’ll incur a steady, progressive fluid deficit. It's important to practice drinking while running at marathon race pace until you get good at it.
Phil M.
-- "Learn from the mistakes of others. You can't live long enough to make them all yourself." Martin Vanbee