Ambulances All Night Long
The Avon Breast-Cancer 3-Day Walks had a sad history of medical problems among the walkers challenged to walk 20 miles a day for three days, often in temperatures above 80F. The 2000 DC 3-Day Walk sent so many to the hospital that the next year they shortened each day's course. Even on the shorter course, as a traveling walker in 2001 I experienced heat illness by Mile 10. I crewed the Seattle 3-Day Walk in 2001 and was horrified at the 5 block-long line-up of ambulances as walkers had to face 90F temperatures on a course that included difficult hills in full sun on Day One.While most of those sent to the hospital had dehydration and heat illness, I have personally heard from walkers diagnosed with hyponatremia who swore they were drinking both water and sports drink. The 3-Day Walks stressed drinking before you are thirsty and eating before you are hungry. Did the walkers drink too much?
Obedient Walkers
As identified in the Noakes paper on marathon fluid intake, those new to long distance walking and running are often more obedient to guidelines to keep drinking throughout the event and to drink before they are thirsty. I heard a similar theory during my marathon coaching certification class from experienced coach Patti Finke.These same walkers and runners are often concerned about weight and may avoid sports drink for its calories and flavor. They may be watching their sodium and avoid salty snacks. All of this can set them up for drinking too much water and not taking in enough sodium on long walks and runs.
Rules of Thumb Needed
As Dr. Jack Scaff of the Honolulu Marathon Clinic said, it is next to impossible for runners and walkers to be calculating exactly how much and when to drink when out on the marathon course. Almost everyone is so fatigued by Mile 18 than any attempts at keeping track are out the window - and who among us has a coach following us every mile handing us exactly the right amount to drink?Individual variation will also gum up most attempts to be precise. Overweight people are more prone to overheat. Studies are often done on athletes and don't show how the same guidelines will affect those who are older, who are on medications including the common ibuprofen, those with declining kidney function, etc.
Tell most US walkers to drink 400-800 mL of water and sports drink an hour and the result is extreme confusion. For that reason, I offer general guidelines relating to a sports water bottle and English units.
Water Bottle = 16-20 oz. bottle, the common size sold for bottled water or the reusable bottle that comes with a water bottle fanny pack. Don't know how big your bottle is? Check the label, or use a 12-oz. can of soft drink and pour it in and see how much that fills it up. A cup measure is about 8 oz.
Sane Drinking Levels
Checking my own published guidelines, which followed conventional marathon coaching guidelines, they are pretty much within the 2005-2006 guidelines. I have edited them to stress letting thirst be your guide, unless you have proven it to be unreliable through the "weighing before and after" method.Drinking Guidelines 2006
Drink about a cup of water or sports drink each mile, or a sports bottle full of water or sports drink an hour, whichever is less.
Camelbaks and other hydration backpacks pose a problem for gauging how much you are drinking. Those using them need to let thirst be their guide and to check levels before and after their training walks.
Be safe out there - I have seen walkers dropping like flies in hot weather, don't let this happen to you!
Drinking Guidelines for Walkers and Runners 2006
