Hydration - How much is too much?

Having lived and worked

Having lived and worked outside (Army) for a few years of my life, about 8 months in the desert (135 degrees F with single digit humidity) and the rest in the southern Appalachian mountains (95 degrees F with 80% plus humidity) while being responsible for my own hydration and that of many others, I've had some experience with what works well and what doesn't. Here are a few simple guidelines:

Drink lots of water. It is the original and best hydration drink there is. It weighs roughly 8 pounds per gallon and makes up around 60 and 70% of your body's materials. With that ratio, it's weight well worth carrying, and it carries much more easily inside than when hung on the outside in various containers.

You will perform much better and more efficiently when you remain hydrated properly.

You can't drink too much. The few exceptions you've probably heard about are media-circus-driven medical anomalies or individual abuses (deliberately not peeing while consuming massive amounts of water). Your body has an automated system for getting rid of excess water. If you're peeing (and your urine is clear) so often that it's an inconvience, you can probably safely back down your hydration a notch or two.

Staying hydrated is much more efficient and healthy than continually "draining and refilling the tank." Doing this won't kill you, but it's just not as good as maintaining the even keel of a healthy hydration level.

Room temp is best.

Sipping slowly allows for much more efficient absorption than chugging, although chugging does feel good sometimes. Sipping will also help reduce sloshing due to the more efficient absorption rate.

Being thirsty means you should have been drinking more water much earlier. Thirst is a warning alarm, not a mere friendly reminder. By the time you're thirsty, your body's water tank is nearing the healthy "Empty" mark.

The clearer your urine, the better. The darker yellow it is, the more you need to be drinking IMMEDIATELY. Watch it and start to rehydrate way before it gets deeply colored. If you're not peeing at all, stop what you're doing and drink water.

Caffiene is a diuretic (forces water out of your system).

It takes almost as much water as is in fully sugared beverages (sodas, southern sweet tea, etc) to process the sugar out of your body as are contained in those beverages.

Put caffeine and sugar together and you're wasting the vast majority of the water in that beverage.

Cold drinks (including water) generally shock your body when your core temp is up. Not a good idea, and usually feels unpleasant in a variety of ways, especially if you're continuing to maintain an elevated core temp.

Much of this has already been covered previously. I just wanted to put all of this experientially gained knowledge (mine and everybody else's) in one place. Hope it helps. It's kept me healthy and alive in some of the harshest environments in the world while performing extremely difficult labor.



Phil
 
Todays run was 19 miles. Not

Todays run was 19 miles. Not brutal humidity but uit was mid to upper 80's

Loaded up the Nathan with 70 oz of 1/2 strength Accelerade. and the handheld with 20 oz.

Ran 5 miles and refilled the handheld at a starbucks. I wasn't running out of water this time. I mad certain I gu'd every 30 - 45 minuted and drnak all I wanted. at 16 miles teh wife met me with water. It was Ice water but man it tasted so damn good after all the sweet crap. I guzzled some and refilled the handheld and I was off for the final stretch. I still had a little in the backpack too. Last two miles are all uphill without a break. Nastyu patch when you hit the wall. But this time I continued past Mc'ds and hit home.

Starting weight probably 224 and ending weight 216. I thought that was acceptible loss.

Total consumed 70+20+20+20=130 oz liquid. I felt good the whole run except the last two miles, I was dragging pretty bad.
  • Run Time: 3:21:42
  • Distance: 19.08 miles
  • Average: 10:34 /mile
  • Fastest Pace: 7:56 /mile
  • Calories: 3047
That would be a sub 4 1/2 hr marathon. I am happy with that.

I am slow but I am persistent ;)
 
So I started a log of runs

So I started a log of runs and data

I am tracking Temp, Humidity, Dewpoint, Cloudcover, Time, Distance, Start Weight, End Weight, Water in, Weight Loss.

Basically all the data I can and working out a sweat rate. So far it is kinda scary. Average at 89 degrees and 69% humidity I lose 1.14 oz per minute. That works out to 1/2 gallon per hour and if I really plan on running a 50- miler 5 galons of water loss. It isn't the water loss that bothers me, it is the water absorbtion rate. Most people can absorb around 30-40 oz per hour leaving me at a 20 oz deficite every hour I run. Now granted, the temps in November will be lower and I assume by that time I'll be 15 - 20 lbs lighter but still I am going to really have to monitor this if I plan to finish the race.

What I hope from all this is to come up with enough data that I can predict water needs going forward at any temperature and body weight for myself. Then I know what is realistic and what is fantasy.

It was funny, two nights ago I ran a twilight race. At the end I looked around and there were people with wet backs, wet shoulders, water spots and sweat but I was literally dripping. As I got animated moving my hands talking water was flipping all over the place. I saw a few others as soaked as i but we were certainly not the norm. I would have shaken their hands but they were gross with sweat ;)
 
Jimmy Hart wrote:I remember

Jimmy Hart said:
I remember when I first gave my recommendations for hydration in this thread and I believe I was called something akin to crazy :)

something like 6-8 oz every 20-30 minutes during runs in temps of 80 or more.
You are crazy, I'd be dehydrated in 4 hours at that rate ;)
 
The guys over at

The guys over at sportsscience http://www.sportsscientists.com/search/label/dehydration have done a few articles of hydration, and dispel many of the common myths about hydration. (for instance, the consumption of water does not affect your core body temperation in any significant way) Noakes', Lore of Running also has lots of info on the science behind hydration, and what REALLY happens. So much of 'what we know' is based on marketing information rather than actual science, just like the shoe industry.

In the end, drinking according to your thirst is, IMHO, the best strategy; it's a highly evolved mechanism specifically to avoid dehydration.

Personally, I will comfortable run 2hrs of hills without taking any water in up to the lower 20 degrees C. I try to drink 750ml of water and hr or so before before, and the same immediately after.



Marc
 
Marc, keep in mind, everyone

Marc, keep in mind, everyone is different.

If I tried to run two hours without water, I would be in trouble. It is that simple.

I do think we over electrolyte ourselves. Before gatorade people broke down and shite themselves. Now, like vitimins, we tend to overdo it.
 
Yes, agree that we're all

Yes, agree that we're all different. That's one of the reasons why drinking to thirst is what I advocate.

When I started to take an interest in minimalist/barefoot running, I was quite surprised to find that the need for shoes was not the only place where myth or bad/non existent science was the basis for what is regularly stated as fact. (and much of it is around hydration)

Lactic acid build up is the cause of muscle pain

You can't drink too much or all weight loss during running is due to lost fluid, and should be 100% replaced

Dehydration causes cramp or heat exhaustion

You can lower the bodies core temperature by drinking cold water

You need to replace the electrolytes lost through sweating

All these things at best, have no scientific basis. Most have been proven to be false, but they continue to be written and talked about as if they were proven fact.

Marc

(Sorry to 'go on', but hydration is a pet peeve of mine. My hope is that this community, having seen through the running shoe myth, might be more receptive to re-evaluating other area)
 
Marc I was getting all revved

Marc I was getting all revved up reading your last comment. I thought you were saying that list was the way things worked and I was trying to decide how to politely discredit all of that! I'm so glad you finished that by saying those were things that are commonly misconstrued. Whew that saved me a whole lot of typing!
 
I don't know if it's true or

I don't know if it's true or not, but I remember reading somewhere that in either the New York or Boston marathons, they have never had to take a runner to the hospital for dehydration, but have had to take runners to the hospital for overhydration.