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Maia
(maia) - MLife

Locale: Rocky Mountains
Hydration for Lightweight Backpackers on 07/23/2013 14:19:15 MDT Print View

Companion forum thread to:

Hydration for Lightweight Backpackers

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Hydration for Lightweight Backpackers on 07/23/2013 18:09:14 MDT Print View

Kevin, A great summary of hydration. Thanks!

Rex Sanders
(Rex) - M

Locale: Central California Coast
Re: Hydration for Lightweight Backpackers on 07/23/2013 18:48:42 MDT Print View

Thanks for the overview.

A few more tips:

– Your hydration and salt needs will change over time. What you need (or didn't need) in your 20s is not the same as in your 50s. What worked last year, might not work this year. Pay attention to your body! Ask me how I know :-)

Thermotabs salt pills have 180 mg Sodium, and are relatively cheap and widely available.

– Remember: Everybody is different.

-- Rex

Edited by Rex on 07/23/2013 18:50:26 MDT.

Johan Engberg
(luffarjohan) - M

Locale: Wrong place at the right rime
Intrestning on 07/24/2013 01:39:48 MDT Print View

Thanks for the article, the subject is quite intresting. I've had a lot of emphasis on dealing with cold temperatures but not so much with hot weather.

I've made my own poor mans sports drink using salt-packets from McDonalds and other lunch restaurants. Can't remember the weight of each packet though but I thnk it was something like 2g.

/J

Edit: Spelling

Edited by luffarjohan on 07/24/2013 01:43:37 MDT.

Donna C
(leadfoot) - M

Locale: Middle Virginia
Re: Hydration for Lightweight Backpackers on 07/24/2013 07:56:34 MDT Print View

NUUN brand electrolyte tablets are pretty good as well and come in some great flavors. They now offer different types of tablets according to activity.

Sara Marchetti
(smarchet) - MLife
Re: Re: Hydration for Lightweight Backpackers on 07/24/2013 08:56:57 MDT Print View

This year, company under the sun has come out with an electrolyte supplement like Nuun. When I went into REI a few weeks ago, I was blow away by the choices. As a trail runner, I get into the habit of religiously taking salt supplements every hour. I prefer Nuun while my wife prefers SCaps. I highly recommend salt supplementation to backpackers as well. Many people have told me that they get an extra zip in their step after such supplementation. The truth is most likely that they aren't dehydrating and thus feel more energized than normal. We live in a dessert/high altitude climate so we don't have much of a choice. I'm not a big fan of other forms of electrolyte replacement because they tend to be too heavy. If you want your best bang for weight, I'd go with the capsules like SCaps. The weight is negligible.

Edited by smarchet on 07/24/2013 08:57:28 MDT.

Sara Marchetti
(smarchet) - MLife
I spy on 07/24/2013 09:00:21 MDT Print View

I spy Hoka Mafate shoes in that picture with the young boy! Great shoes for rocky conditions! I have a pair myself. Do you backpack in them?

Rod Braithwaite
(OddRod)

Locale: Salish Seashore
Re: Re: Hydration for Lightweight Backpackers on 07/24/2013 09:31:08 MDT Print View

Two of the NUUN tablet flavors also contain 40mg of caffeine: Kona Cola and, IIRC, Lemon Tea.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Re: Hydration for Lightweight Backpackers on 07/24/2013 09:51:35 MDT Print View

From Kevin's article -

"How about electrolytes? By far the main electrolyte we lose in sweat is sodium. In high exertion activities such as running athletes can lose up to 0.07 oz (2 g) of sodium per hour.

"Backpackers are unlikely to lose anywhere near that much unless environmental conditions and their duration and level of exertion are well beyond the norm.

"Additionally most backpacking foods contain high concentrations of salt/sodium. However if you’re drinking 0.5 to 1 L of water per hour, you may need to consider salt supplementation."


Just for reference -

SaltCaps2


The typical replacement target is one gram of sodium per liter of water.
---Edit: IF event duration and conditions suggest the need....Go back and read the article!
MYO Caps: '00' gelatine caps filled with table salt.
Costs are "typical", no "digging for deals".
Edit: "Active Nunn" sodium content corrected.

Edited by greg23 on 07/24/2013 14:58:42 MDT.

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Hydration for Lightweight Backpackers on 07/24/2013 11:23:32 MDT Print View

1. My comment about most running events lasting only 10-14 minutes referred to an example I removed about the 1500m-3000m races the kids I coach race. Obviously most adults race 5-10K and beyond: the longer the race time the greater the risk for dehydration. Sorry about this miss in editing.

2. Agree with Rex--it's unclear how age affects sweating/salt BUT clearly if you're not acclimated to heat you could get very different results using the same hydration strategy.

3. Johan: I often make my own recovery beverage by adding ~1/8tsp of table salt per quart of whatever I'm drinking. Cheaper than anything else you can buy! paper packets would be prone to moisture unless protected.

4. Donna/Sara: Yes, I love Nuun. If I'm really thirsty little else tastes as good. For lightweight backpacking there are lighter ways to replace your sodium--each tablet has ~350mg. (There are three varieties of Nuun with different sodium content--this refers to Nuun Active: Each tube of Nuun contains 12 tablets. Each tablet makes 16 oz. of Nuun, and delivers 360 mg Sodium / 100 mg Potassium / 25 mg Magnesium / 13 mg Calcium)

5. Sara: Yes, Carson backpacks in Hokas. He had a heel problem from running (now resolved). I've used them for backpacking a couple of times when I had an old pair laying around but use them mostly for steep trail running.

6. Greg: See #4-The "Active" Nuun has 360mg sodium per capsule: "U Natural" and "All Day" produces have less/no sodium. Thanks for the comparison table!

I'll be in King's Canyon for the next few days and unable to respond to comments until I return.

Edited by ksawchuk on 07/24/2013 12:29:09 MDT.

Mick Connolly
(mickconnolly7)

Locale: Sierra Nevada's
Sea Salt on 07/24/2013 13:07:16 MDT Print View

Why wouldn't you use sea salt that has up to 50 trace minerals rather than table salt?

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Sea Salt on 07/24/2013 13:17:26 MDT Print View

No specific reason except it's cheaper and what I have. I figure I get my trace minerals from my healthy and varied diet and a multiple vitamin per day. Absolutely agree that avoiding processed foods is a good thing though.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Sea Salt on 07/24/2013 13:17:37 MDT Print View

Mike,
Works for me. If you've got sea salt, use it. Just depends on personal preferences.

Others elsewhere here (search electrolytes) use a mix of regular and "lite" salt to take advantage of the potassium.

Edit: A recent thread on electrolytes.

Edited by greg23 on 07/24/2013 13:53:33 MDT.

Lisa Wilkins
(wilkinld) - M
Hydration on 07/24/2013 14:15:35 MDT Print View

I've tried a liquid product called Elete with good success. It has everything you need: potassium, chloride, magnesium, & sodium with no sugar, flavors or junk. Although the formula may be overkill for the average hiker/backpacker it's dummy proof. Since it's liquid you can just decant what's needed for your trip length into a small plastic bottle. It's cheap, light and doesn't have much taste. I just add it to my water bladder with each refill. Found on website: basegear.com but I'm sure it can be found elsewhere.

Curtis B.
(rutilate) - MLife

Locale: New England
Timely write-up on 07/24/2013 14:16:59 MDT Print View

This write-up was timely, and I appreciate Greg's summary table. I ordered s!caps right away.

I would've liked to have seen a bit more of the medical background in the writeup. There is an awful lot of hype out there--how do you tell what is marketing vs. reality?

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Timely write-up on 07/24/2013 14:21:43 MDT Print View

What were you hoping to know that wasn't covered? It's not clear from the article but I am a physician and can add additional information. I tried to strike a balance between the practical and technical--but can be more technical if you have a specific question!

Curtis B.
(rutilate) - MLife

Locale: New England
Re: Re: Timely write-up on 07/24/2013 14:43:58 MDT Print View

Kevin wrote:
"What were you hoping to know that wasn't covered? It's not clear from the article but I am a physician and can add additional information. I tried to strike a balance between the practical and technical--but can be more technical if you have a specific question"

I had no idea you were a physician. While I applaud your understatement, it might be valuable to include your credentials (at least an M.D. behind your name).

Here are some further questions that I'll let you be the judge of whether or not they belong in the article.

How much variability in the quantities of water/sodium for people who sweat profusely? My teen son doesn't sweat at all. Not even in sweat tests at the doctor. Me? I sweat profusely. I can be drenched head to toe in a humid environment within an hour, and consume 5 liters of water in ~6 hours of hill hiking and still be dehydrated with dark yellow urine. Should I be consuming more

I like your guideline of adding 300-600mg sodium per liter. Is there a guideline for total sodium I should be consuming that I can look at my meals and beef jerky to balance? Should I be worried about ensuring I don't overload?

You talk of sodium. What of all the other electrolytes that other companies are adamant that we'll keel over without? My understanding is that Magnesium is important, but a quote I just found onthe Succeed website: “Magnesium is another intracellular ion that, like potassium, is lost in sweat and urine during exercise. But the losses are trivial. There is no published evidence showing that magnesium deficiency is either common amongst the physically active, or that magnesium supplementation can either increase the intracellular magnesium stores, or enhance performance.” Dr. Timothy Noakes Sports Nutrition: Fluid, Electrolytes, and Minerals (Report from the World Forum on Physical Activity and Sport, Quebec City, Canada, 1995.)

The symptoms of hyponatremia sound very similar to dehydration: poor performance, cramps, lightheadedness, low blood pressure. Are there better differentiators? Are there field tests that can be performed for both (ie.I had forgotten about the pinch test for dehydration)?

Thanks!

Michael Simms
(Mtnmanmike)
Water Bottles vs. Hydration Packs on 07/24/2013 16:21:00 MDT Print View

One aspect of hydration is the storage container used. Over the last couple of decades, most people have switched over to using water bladders in their packs as they appear to be convenient. Having used them for years, I know that they are awesome for mountain biking or motorcycling, but I prefer using plain ol' disposable bottles for the hiking trail. Why? One reason is that I don't need to take up valuable "real-estate" in my backpack for water. Another is that I have no risk of leakage on my gear. Lastly, I always know how much water is left. I usually only carry two liters at a time, but occasionally carry three (two 1.5 liter bottles). With my Sawyer filter bag, I can expand my capacity to five liters (Ugh!) The disposable bottles weigh very little as well. I like the smartwater bottles, but find myself looking for new styles when I go to whole foods or other high end outlets. If a bottle gets trashed, guess what? Another one is as close as the nearest liquor store!

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Re: Re: Timely write-up on 07/24/2013 16:58:00 MDT Print View

1. "How much variability in the quantities of water/sodium for people who sweat profusely?"
A. A lot! I almost didn't want to give specific advice about how much to drink and how much salt to take but you've got to start somewhere. People can lose up to 2g of sodium per hour and ~2 liters per hour. I'd advise that you replace to thirst, to relatively clear urine and to take ~600mg of sodium for every liter of water they drink. You're not likely to get into problems within these parameters because we have a lot of excess salt in our diets and our kidneys can regulate fluid and sodium pretty well (unless you have a problem with your kidneys of course!)

2. "What of all the other electrolytes that other companies are adamant that we'll keel over without?"
A. You actually quoted the author (Timothy Noakes) I used partially as my source for this article. Evidence is that sweat losses of Potassium, Calcium, Magnesium are very small and Zinc pretty small. They probably don't hurt (unless they upset your stomach) but you probably don't need them under most circumstances.

3. "Should I be worried about ensuring I don't overload?"
A. See last sentence of #1 above--you can regulate pretty well. It is more likely that you'd overload with water than salt. Studies at Western States have found a correlation between salt craving and hyponatremia (low sodium). If you crave salt you probably need it, if you don't you probably don't. (Excepting that if you're REALLY far gone and have nausea you may crave nothing!)

4. "Are there field tests that can be performed for both (ie.I had forgotten about the pinch test for dehydration)?"
A. That's a tough question. If your skin is "tenting" on the pinch test you're probably REALLY deyhdrated: it's not a sensitive indicator. Whether you crave salt (or not)may be a potential indicator of enough sodium (see #3 above). Your thirst is certainly an indicator of dehydration and Dr. Noakes (see Waterlogged: http://www.amazon.com/Waterlogged-Serious-Problem-Overhydration-Endurance/dp/145042497X ) feels that it is an adequate enough guide of hydration even for athletes. Finally a potentially embarrassing answer that I'll rely on the mature and sophisticated members of this forum not to "Ewww!" about. We all come with a built in sodium sensor (our tongues). I've tried to taste a drop of my urine during Western States and other high intensity trips to see whether it tasted salty or not. If it does my body is wasting salt and probably has enough, if not, I'm unlikely to do harm by taking a little more.

Have fun with that one!! (Urine is generally sterile and anything living there is not likely to be too happy in your stomach.)

John S.
(jshann) - F
Re: Re: Re: Timely write-up on 07/24/2013 17:05:30 MDT Print View

Wilderness and Environmental Medicine journal has an article in press about hyponatremia. A chart gives signs and symptoms of exercise-associated hyponatremia vs heat illness vs altitude illness. The only differentiating signs/symptoms in some situations were temperature, respiratory distress and diuresis. It goes on to say "...the only reliable method of diagnosing EAH at present is through measurement of serum sodium concentration."

Odd that they didn't mention skin turgor.

Edited by jshann on 07/24/2013 20:20:25 MDT.

John S.
(jshann) - F
Re: Re: Re: Re: Timely write-up on 07/24/2013 17:10:32 MDT Print View

Some online hydration articles say our urine should be clear. The term clear is a description of clarity and not color. Our urine should be colorless or pale/pale yellow, not dark yellow or dark any other color. Of course some foods and meds may change the color.

Edited by jshann on 07/25/2013 07:59:27 MDT.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Light and dark urine on 07/24/2013 20:15:06 MDT Print View

Light and dark urine is not ONLY caused by dilution. It may be that you are simply not eating enough and your body is metabolizing more fats and protiens from it's stores. Usually, such muscle damage is associated with highly active people and is repaired during the period of recovery that follows (often overnight, but may extend to 48 hours. Like everything else, bodily repair can be accilerated by constant use.) Even though you drink normally, your urine can change color. This is usually not much concern, but don't go into panic mode and start drinking more than you need. This will just flush salt and trace elements out faster. Get comfortable with your metabolism. Knowing what a normal variation in the color of your urine is will help.

M B
(livingontheroad) - M
urine on 07/24/2013 20:40:48 MDT Print View

is your urine clear at home?

Not to be too personal, but mines not.

Some foods/medicines, etc can color it too.

Yeah, if I drink a lot, so that I pee it all out every 30-60 min, it runs pretty clear.

But thats not reality,thats being overly conservative with fluid intake.


A better indication to me most of time , is my saliva.

When it starts to get thick and sticky, I know Im getting dehydrated.

Kathleen B
(rosierabbit) - M

Locale: Pacific Northwest
Hyponatremia and a "gatorade" recipe on 07/24/2013 21:20:25 MDT Print View

Several years ago on a hot summer day four of us hiked to Mt Persis, a short (4 miles roundtrip) hike with about 2600' gain. One woman drank 7 liters of plain water during the hike, convinced she needed the water because "it was so hot." She didn't want any electrolyte supplements. We told her she was drinking too much water. She fainted when we got home, which reinforced her belief she should have drunk even more. Nothing we said would convince her otherwise. Mindset can be a serious roadblock to sensible hydration, whether it's too little or too much to drink.

I got this recipe for a homemade electrolyte drink that works quite well if you don't want to by the commercial versions. I wish I could remember where I got it to give proper credit.

1 package koolaid, any flavor
½ C sugar
¼ ts salt
1/8 ts salt substitute
8 C water

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Hyponatremia and a "gatorade" recipe on 07/24/2013 21:39:41 MDT Print View

Ha, hey, you can also substitute an 1/8 to 1/4 cup wine vinegar or cider vinegar for the koolaid.
I always called it Farmers Drink from my days working on the farm with my grandfather.

Edited by jamesdmarco on 07/25/2013 04:45:20 MDT.

Steven McAllister
(brooklynkayak) - MLife

Locale: Atlantic North East
Hydration for Lightweight Backpackers on 07/25/2013 05:16:16 MDT Print View

Also not mentioned is about how diuretics, blood pressure and other medicines can contribute to a lack of electrolytes.

I am a fan of "Light Salt". It's cheap, common, and contains sodium and potassium salts.

Shawn Bearden
(ShawnB) - F - MLife

Locale: SE Idaho
Well done and a note on food on 07/25/2013 08:47:29 MDT Print View

Kevin has clearly done his research because he is 100% spot on throughout his article. Well done, Kevin!

As a side note, because the MD degree was discussed. Folks should be aware that medical schools provide little to no training in either nutrition or the physiology of exercise. Having an MD degree does not mean, per se, that a person knows what they are talking about any more than the next educated person in these areas. Additional training is necessary.

Another post mentioned:
"Light and dark urine is not ONLY caused by dilution. It may be that you are simply not eating enough and your body is metabolizing more fats and protiens from it's stores..."
This is absolutely not true. While I am an expert in the physiology of exercise, I am not an expert in the urine composition under severe starvation but for anything remotely encountered even in survival situations by backpackers or endurance athletes, sources of fuel for energy and what macronutrients (carbohydrates, fats, proteins) you consume will not alter urine color. By the way, the majority of the energy for the exertion levels encountered by most backpackers comes from fat. Fat metabolism is highest (as a percentage of total energy) at rest and declines as carbohydrate utilization increases with higher levels of exertion.

"...don't go into panic mode and start drinking more than you need. This will just flush salt and trace elements out faster."
Again, not quite true. Drinking water, even in large amounts, will not flush electrolytes. The kidney is very good at adjusting electrolyte and water compositions as needed. It is, however, good advice to not force water down if you are not thirsty(with the exception of those reaching a level of dehydration and exhaustion where the body's normal thirst mechanisms are compromised).

If I misinterpreted either of these statements, I apologize but I wanted to clarify for any naïve readers who might interpret them as I did.

Finally, Kevin noted the importance of food in the equation but there isn't any information added that I could see in the article. The importance here should not be underestimated. Sweat sodium losses vary from about 20 to 70 mEq/L of sweat, or about 460 to 1600 mg/L (mEq/L x 23 = mg/L). For a typical day on the trail (if there is one) in warm conditions, one might lose 1-4L in sweat. Typical U.S. intakes of sodium are about 3.5 g/d. I doubt that is the case for many on this forum who are more health conscious but it puts things in perspective. The good news is that many common 'healthy' foods contain lots of sodium. One ounce of beef jerky contains about 0.5 g sodium, one ordinary pickle contains about 1 g sodium, a can of soup and a few pretzels 2 g. Take a look at any dehydrated packaged food you take - much of it has very high sodium content. So they certainly can help replace. In general, MRE's provide Soldiers 3 g sodium per day, plus a salt packet is added and encouraged 'if' weather is hot (6 - 8 L/d sweat losses living in Iraq in summer) and in particular if operational circumstances prevent full consumption of the MRE.

So, be sure to look at your sodium intake in food across the day. There is a very good chance that the vast majority of people on this forum will not need to supplement their drink when food is considered and maybe planned appropriately (such as shifting some of the salty foods already taken to breakfast and lunch rather than all at dinner). Regarding other electrolytes (in addition to sodium), the diet will provide these unless you are eating very poorly.

Again, Kevin...excellent article with very good practical advice that helps to demystify and de-hype the electrolyte and sodium craze.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Well done and a note on food on 07/25/2013 10:30:48 MDT Print View

"...sources of fuel for energy and what macronutrients (carbohydrates, fats, proteins) you consume will not alter urine color."
I do not believe this is true. Uric acid, a break down product from metabolizing fats and protiens is the primary coloring agent for urine. It is yellow to brownish in color. It is normally excreted through the urine. There are two avenues for the color of the urine. First is water: too much can dilute it a lot, or, too little can cause it to become very concentrated. This is what most hikers think of as watching your urine color. Second is the uric acid itself: producing more or less depends on your diet/excersize level. Eating a large amount of beef jerkey for example will cause your urine to be more yellow without effecting the bodies homeostasis. The excess protien the body does NOT need will be metabolized for energy, causing the nitrogen radical (urea cycle), to be excreted. A normal person's urine color can change over many shades with no hint of dehydration. High protien diets (fresh fish and chicken for example) often cause very yellow urine, despite drinking adequtly (and without the salt usually found in beef jerky.)

"Most of the uric acid is removed from the body in urine. A small amount passes out of the body in stool. But if too much uric acid is being produced, the level in the urine will increase. If the kidneys are not able to remove it from the blood normally, the level of uric acid in the urine will decrease."

Yes. In hot weather (the primary subject here) you sweat. A large amount of eric acid passes out of your body through the sweat. In this context, your skin becomes an organ of excretion, too. This was exactly my point above without the more technical details, of course.

"... Drinking water, even in large amounts, will not flush electrolytes. The kidney is very good at adjusting electrolyte and water compositions as needed. It is, however, good advice to not force water down if you are not thirsty(with the exception of those reaching a level of dehydration and exhaustion where the body's normal thirst mechanisms are compromised)."

Generally yes, I will agree with you. But we are talking about a person sweating a lot of salt out, ie, within normal conditions, but on the low end. Drinking more than you need in such a situation will act as a "sponge" causing the salts to flood into the water. You can easly loose too many salts and go into a hypernatrial state. Be a bit carefull about drinking lots of water with no electrolytes. I just did that on the NPT, drinking more than I needed at a cold stream. I got a bit disoriented and nasueous. I had to sit down and think a minute before recognizing I needed some salt, too. The big clues were I was soaked with sweat, 90+F day, hiking fairly hard for over 2 hours, ate a little, but only a couple bites. I finished my water bottle, filled them up zapped them and drank them, filled them up and zapped them and packed up to leave. About a liter and a half was enough to make me very light headed. This is BEFORE the water even hit my kidneys, maybe 7-8 minutes.

George Davis
(nsiderbam) - F

Locale: mid-Atlantic
TRT on 07/25/2013 11:27:49 MDT Print View

It was kind of funny to read your comment about fast packing the Tahoe Rim Trail. I'm actually thru-hiking it right now and, due to a series of unfortunate events, ended up missing Spooner Lake and did an almost-40 mile day in search of water before ending up at the lakeside inn in South Tahoe. Won't make that mistake again, but fortunately I'm pretty much through with the dry sections.

Good article!

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Re: Well done and a note on food on 07/25/2013 11:36:26 MDT Print View

I'm going to specifically comment on this statement as not having full information could lead to problems:

"Drinking water, even in large amounts, will not flush electrolytes. The kidney is very good at adjusting electrolyte and water compositions as needed."

This is generally correct. However the kidney can not control the very large losses of sodium that CAN occur through sweating. You can lose enough sodium from sweat to cause problems. If you're replacing the fluid you've lost with water (or other low/no sodium drink) you will run into problems with hyponatremia.

As for food sources of sodium you are absolutely correct. If you're exercising only in conditions where and to the level of needing 1-3 liters of fluid per day to replenish it is likely that your diet contains enough sodium that you don't need to take additional salt. However I have been on backpack trips where I needed a liter per hour for a good portion of the day. With my hiking days frequently lasting 10-12 hours at a high intensity I have occasionally needed to take salt pills. Everyone needs to consider the conditions they're exercising in, the duration of their exercise, how much they're drinking, how much they're sweating and have the tools on hand to stay hydrated. This MAY include salt supplementation in particular conditions and for certain people. 30 mile days through the Mojave Desert on the PCT will require more than 12 mile days in the High Sierra.

You are also correct that a physician may not have the level of practical information to guide a runner or backpacker. I'll add to my credentials 10 sub-24 Western States finishes, a (now-broken) JMT trail record, serving as medical captain of the Michigan Bluff aid station at Western States and being involved with studies on hyponatremia.

HYOH

Shawn Bearden
(ShawnB) - F - MLife

Locale: SE Idaho
good ideas on 07/25/2013 11:49:09 MDT Print View

Thanks, James. This may be a simple case of taking some accurate information and extrapolating too far, coming to incorrect conclusions. Glad I can help to clarify and correct. This happens quite a lot in my classes where my students do the same thing, but it is only natural and part of what drives good research questions. You are certainly thinking along reasonable lines and the logic would seem reasonable at first view but the outcomes you've hypothesized actually aren't quite what results. Although there are a number of factual errors of metabolism in your response, I'll just correct two that are common. Excess protein intake is not used for energy but is rather converted to fat stores. Protein remains less than 10% of energy sources even in prolonged endurance events. I don't know where you are getting your fish or chicken but any change in your urine color is not due to the protein therein. It is true that some micronutrients and food additives can color urine. Vitamin B supplements are a great example, where all the excess turns urine a bright yellow. Happy hiking!


edits: your 'sponge' analogy is a dangerous one and not at all accurate. Your symptoms on the NPT are not uncommon, from your description of the situation, and were unlikely to be a result of the electrolyte composition of your drink during the rest stop. Though clearly there are situations in which added salt to drinks (or drinking sports drinks) is the better choice over water alone.

Edited by ShawnB on 07/25/2013 16:52:53 MDT.

Shawn Bearden
(ShawnB) - F - MLife

Locale: SE Idaho
Agree Kevin on 07/25/2013 12:05:01 MDT Print View

Kevin, quite right again. This is why I thought your article was so well done. It, to my reading, lays out well that there are indeed important conditions under which supplementation is important. And, I hope that readers also appreciate the other quite accurate information included in your article that routinely supplementing all fluids one drinks is typically unnecessary. Reading some of the comments to your article lead to believe that many people, as I find in my own population, over-consume sodium when exercising. In addition to salt-sensitivity, there is also good evidence that overconsumption of salt causes microvascular dysfunction that is initially unnoticed but can contribute to other pathologies in the long term.

Didn't at all mean to infer you aren't qualified, clearly you are! For full disclosure, I am a professor of physiology, director of my university's biomedical research institute, fellow of the American Heart Association, etc., former professional athlete (soccer) and an exercise physiologist by training.

Edited by ShawnB on 07/25/2013 13:21:18 MDT.

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Re: Agree Kevin on 07/25/2013 12:08:45 MDT Print View

I LOVE the eclectic group of wierd-ohs who lightweight backpack!! :-)

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Re: Re: Timely write-up on 07/25/2013 12:11:12 MDT Print View

Kevin: "I'll add to my credentials 10 sub-24 Western States finishes, a (now-broken) JMT trail record, serving as medical captain of the Michigan Bluff aid station at Western States and being involved with studies on hyponatremia."

Well, OK, Maybe you can relate.

This is BPL though, and everything and everyone is subject to endless opinion and conjecture.

;-)


Thanks Kevin, for a good article and good follow-up.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Well done and a note on food on 07/25/2013 12:19:34 MDT Print View

Kevin stated "I'll add to my credentials 10 sub-24 Western States finishes, a (now-broken) JMT trail record, serving as medical captain of the Michigan Bluff aid station at Western States and being involved with studies on hyponatremia."

For those who are unfamiliar, the Western States 100-mile Endurance Run happens in California, and the course involves roughly 15,000 feet of vertical gain and 18,000 feet of vertical loss. The mid-point of the course (45 to 55 miles) is the hottest part, and the Michigan Bluff aid station just following that sees more than its share of cases involving dehydration, hyponatremia, heat exhaustion, and (gulp) worse. I think if you had to study these maladies in the field, that would be the place to go. The top competitors can knock this out in about 15 hours.

I remember waiting for one competitor there (I was in the support crew), and it was tough enough just standing around in the shade as we waited.

--B.G.--

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: Re: Re: Timely write-up on 07/25/2013 17:08:36 MDT Print View

"Odd that they didn't mention skin turgor."

A possible reason occurs to me: As people age, they lose collagen in their skin and the resulting loose skin tents easily. This could lead to a misdiagnosis in some cases. You might ask how I know. :(

John Coyle
(Bigsac)

Locale: NorCal
Hydration for Lightweight Backpackers on 07/25/2013 23:17:16 MDT Print View

The idea of taking high doses of sodium on the trail seems strange to me. High blood pressure runs in my family. My doctor has told me to limit my sodium intake to 1500mg per day. I have done this and reduced my blood pressure quite a bit. I try to stay away from backpacking foods that have more than 500mg of sodium per serving. I limit my sodium intake on the trail and haven't noticed any adverse effects and I hike in the mountains of Northern California, up and down some pretty strenuous trails. Like the author says, everyone is different.

Nick Gatel
(ngatel) - MLife

Locale: Southern California
Re: Hydration for Lightweight Backpackers on 07/25/2013 23:45:05 MDT Print View

The article is good as it points out potential problems and should alert most of us to watch our requirements for fluid intake and salt replenishment.

But it does not provide specific universal solutions. When hiking many people are going to sweat out more salt (and other minerals) than they normally would in every day activities. Even if your doctor tells you to limit salt intake, hikes can cause you to lose much more salt than normal and too much is bad.

Since year of us is different, and our needs change over time, we need to know how our individual bodies react to higher levels of exertion. We cannot learn this from an article or a book. We must learn from real world experience.

I often hike in deserts. It is not unusual for me to peel off my shirt after several days of hiking and when it dries the shirt is as stiff as a piece of cardboard, it has so much salt in it. I have to wash my backpacks a couple times a year to get rid of the salt.

My personal experience/needs: Sport drinks or mixes in water do not "quench" my thirst. Only ice tea or plain water quenches the thirst. I don't take tea with me hiking (extra weight). Decades ago, from bad experiences, I learned that too much salt loss made me very sick and was dangerous. I tried salt tablets and they upset my stomach; which is unusual, because I can eat just about anything without and upset stomach. I wasn't about to fool around with cutting salt tablets or bringing salt with me. Too much fiddle factor. But I found that potato chips, Frito's, or similar would do the job.

Also, I don't drink constantly when hiking. I stop about once an hour in hot weather for a 5 minute rest and drink water. In cooler weather, not so often.

This is what works for me, and may not work for you.

At my hourly stop, I drink a little water, and then snack on chips. Somehow my body knows when I have eaten enough. Then I drink some more water until I don't feel thirsty.

Donna C
(leadfoot) - M

Locale: Middle Virginia
Re: Re: Hydration for Lightweight Backpackers on 07/27/2013 11:03:15 MDT Print View

What about coconut water? It seems the new craze for electrolyte replacement. Now it comes in powder form. Any thoughts?

Jeremy Pendrey
(Pendrey) - MLife

Locale: California
electrolyte loss and cramping on 07/28/2013 17:44:34 MDT Print View

This is a very interesting article and discussion. Thanks for all the info provided in the comments.

I would just like to emphasize the impact of electrolyte loss on developing muscle cramps and see if others have thoughts on the topic. I am a high sweat hiker so I realize my experience may not apply to everyone.

Years ago I used to drink plain water during hikes and electrolyte mixes in camp in the evening. At the time, I thought drinking electrolytes at the end of the day was enough. On several high exertion trips in the High Sierra I got severe pain in either the hip or outside of the knee that lasted for days and put me out of commission. They resulted in very painful hikes out to trailheads. I eventually learned that I could hunker down for a day and get well enough to continue. The fact that the problem went away quickly and no doctor could find anything wrong of course made me suspicious that I did not have a knee or hip problem. At the time I didn't know what was wrong. But I also learned that using my trekking poles like a foam roller on my hip helped alleviate the pain a bit. This made me suspicious that I was having cramps. (I realize I was a little slow to figure this out but what can I say.)

Then I started adding Nuun tablets to my water on the trail and the problem went away immediately. It apparently had been IT band cramps. And I started supplementing with a salt stick during meal times. The aha moment came when I started to feel the beginning of knee pain, immediately took a salt stick, and the pain went away very quickly (maybe a half hour to an hour).

I pretty much only drink water with Nuun when I backpack now. At times, I've tried to cut back on the electrolytes because I'd prefer not to have so much sodium. But when I've done that the cramps return and sometimes can result in some painful hiking before I work out the problem. Based on the numbers Kevin presented, it appears that maybe I do need as much salt as I'm taking in though. I typically hike all day and try to do moderately long miles over multiple days (e.g., just finished yesterday 8 days on the PCT in the Sierra for 130 miles), so maybe I simply need all the salt.

I relate this info for those that may experience muscle cramps on the trail, but also to see if others have had similar experiences and have found particular methods that prevent cramps. As I said, I'd prefer not to use so much salt but the alternative seems to be not to hike long days and miles in the summer Sierra (unthinkable!).

Thanks.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Re: Hydration for Lightweight Backpackers on 07/28/2013 18:17:43 MDT Print View

Donna C. -

Coconut Water - This is a concentrate to which you add 8 oz of water -

Junk2

So 8 servings to get 1 gram of sodium. And with that you would get 4 grams of potassium.
Not a good ratio, IMHO.

If mixed as directed, you also drank 64 ounces (2 liters) of water.

Edited by greg23 on 07/28/2013 19:49:01 MDT.

Rick Burtt
(rburtt) - MLife
Gatorade powder on 07/29/2013 10:37:20 MDT Print View

Great article. I'm a little behind in my reading having just gotten off the trail and I haven't read the entire comment thread, so I apologize if my comments are duplicates of another's. Walking through a couple burn areas and through some dense foliage (in the same section of trail, in Colorado), I definitely started to suffer the effects of dehydration and a little heat exhaustion. One thing I noticed was the effects of altitude on dehydration. Not sure what the exact mechanism is, but I'm sure it has to do with the efficiency of processing oxygen in the blood.

Anyway, I found Gatorade's individual packets of powder to be lifesavers. Adding one packet to 20 oz of water made an immediate difference in my performance. I've never been one for sports drinks, but this stuff really worked. A side benefit is that it made the water taste better which made me WANT to drink more - I find that I just get plain bored of water. I've tried the Nuun tabs but quite frankly found the taste a bit off - had a bit of an Alka Selzer aftertaste no matter the flavor of the tablet.

For my $.02, I recommend the Gatorade packets.

Rick

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Gatorade powder on 07/29/2013 12:31:49 MDT Print View

Rick,
"...Gatorade's individual packets of powder..."

Which product? Gatorlytes, Endurance, Natural, or something else?

For their Gatorlyte Powder -

Gatorlytes

About $0.70 per packet, or $0.90 per gram of sodium.

Edited by greg23 on 07/29/2013 13:58:40 MDT.

Curtis B.
(rutilate) - MLife

Locale: New England
Re: Re: Re: Re: Hydration for Lightweight Backpackers on 07/29/2013 18:27:32 MDT Print View

I put this information to the test this past weekend. I calculated the amount of sodium from my lunch and snacks and the supplementary amount my wife would need if we used the 300mg/hour rule, and 600mg/hour for myself. We added the equivalent amount of table salt to a water bottle and drank a bit at rest stops, rationing this saltwater/limeaid mix throughout the day.

Before now, 10 miles in the White Mountains has been our absolute max distance and we were exhausted, stiff, sore, and bloated by 3-4 lbs for a couple of days afterwards. With the salt additive, we felt fabulous at mile 6, enough to bag another peak that wasn't in the original itinerary. We hiked 17 miles and I still felt amazing at the end of the day. If it weren't for some foot pain, I could have kept going. I felt no soreness the next day, and on the second day I've already lost all the water weight and am down about 1/2 pound from the morning of the hike (my goal is endurance as well as weight loss).

What an amazing difference. My wife was getting ready to give up on the distance hiking because the toll was too great on her body, but now she's excited about giving me a run for my money in the 100 mile wilderness later this month.

Thank you very much to the original author and those who've contributed.I'm a believer!

Ben Pearre
(fugue137) - MLife
urine colour on 07/29/2013 21:03:10 MDT Print View

"...sources of fuel for energy and what macronutrients (carbohydrates, fats, proteins) you consume will not alter urine color."

Beets.

Yup, if you eat those and forget by the next day, you can misdiagnose yourself just a little :)

Ben Pearre
(fugue137) - MLife
The world beyond sodium on 07/29/2013 21:35:56 MDT Print View

One recent paper ( http://www.biomedcentral.com/content/pdf/1550-2783-7-28.pdf ) found that Gatorade was not a particularly good choice for recovery after high-intensity exercise, and that another drink (Rehydrate by Advocare, containing about the same amount of sodium but a host of other minerals, a different mix of sugars, as well as amino acids) was much better. They used only one measure of recovery; I'm not sure how applicable the measure is, but the authors think that the results show that it could be worth paying attention to more than just salt even for short-duration (but intense) exercise. Any reason to think that water+trailmix won't do about as good a job as the product that their data favour?

I'm just a menial computer scientist, but would the medical people here care to tell me what you think of the conclusion?

Also, I sometimes use WHO rehydration mix (mixed it myself, although commercial versions are available--it's basically sodium and potassium and a whole lot of sugar (and therefore dirt cheap to make)). The glucose makes it perhaps heavier than necessary (although it'd presumably be included in food weight if you were counting on consuming it, although I usually just carry a few packets for emergencies). I think it's designed for rehydrating during diarrhea and other illness that makes normal food consumption difficult, but what do you think of its use as a sports drink? Would the older, higher-osmolarity WHO solution be better for sports rehydration than the modern reduced-osmolarity one?

I like the idea of using sea salt; I'll have to try that the next time I mix up a batch. Sadly, I lack the resources to do double-blind trials of WHOmix with sea salt vs. iodised table salt... but I believe the non-NaCl in sea salt is only present in irrelevant quantities...

Edited by fugue137 on 07/29/2013 21:59:10 MDT.

Todd ~
(Narrator)

Locale: The front range
My Thoughts on 08/03/2013 22:35:13 MDT Print View

@Kevin - physicians are quite expert at fluid management. All of them, but especially any in family practice, internal medicine or its subspecialties, anesthesiology, emergency medicine, or any surgical specialty. Those physicians manage intravenous hydration all day, every day, your suggestion that they don't understand what they are doing is laughable. As is your suggestion that one cannot induce hyponatremia by excessive water consumption. Please google "non-psychogenic polydipsia with hyponatremia"

Products designed for running a distance race do not translate especially well for hiking. I use endurolytes tablets when running for electrolyte replacement, along with plain (free) water for hydration, and mango baby food squeeze packets for calories / nutrition. This combination is great because they are the most healthful options I can use without breaking stride.

I don't use any of these when I'm hiking (except plain water). These products are great because they can be consumed on the run. I run endurance events at seven to eight miles per hour. Even my fastest hiking its half that pace.

At three to four miles per hour, one can consume real food that he likes. My favorites for the trail are salty / sweet Sahale snacks nuts, organic beef jerky, and homade empanades. Plus plain water. I also bring some fresh colourful fruit like blueberries or fresh mango. This provides electrolytes, anti-oxidants, micronutrients, calories, and hydration.

One should consume enough plain (free) water with this food while hiking that he is making clear urine every one to one and a half hours. Needing to urinate more frequently than this indicates excessive water comsumption. One should also make clear urine in everyday life, else he is putting undo strain on his kidneys and setting himself up for kidney stones.

Kevin Sawchuk
(ksawchuk) - BPL Staff - MLife

Locale: Northern California
Fluid Management on 08/03/2013 23:00:50 MDT Print View

I in no way suggested physicians don't know how to manage fluids. I am a physician. My closest comment, "You are also correct that a physician may not have the level of practical information to guide a runner or backpacker." is correct in many instances. Give a physician a blood pressure (including orthostatics), sodium, BUN, creatinine level and they'll get your fluids right.

Ask a physician not experienced with fastpacking or ultrarunning how much fluid or salt a person needs, how they should plan a drinking, eating, sodium strategy and they'll be unlikely to help you. Especially without the fancy tools we use to guide us.