Hydration Preferences

[zippetydude]

Walt: Wow, I hadn't heard the part about thermoregulation. Sometimes after a very long run I'll do something minor like take my shirt off and all of a sudden be hit with violent shivering that will continue until I bundle up. I wondered where that came from. It may be caused at least partially by dehydration. I wonder if exhaustion plays a part as well, or if it's purely dehydration. If so, I really need to be taking in more fluid.

Ellen: So multiple forms of sugar will be absorbed more quickly than a single form?

Florian: I haven't raided the bucket just yet, but if I don't meet its owner on the trail this weekend, who knows what might happen? I hope to see you in person on your way back down on Saturday.

z

[Ellen]

Howdy Z,

Ellen: So multiple forms of sugar will be absorbed more quickly than a single form?
z

Short answer -- yes. Long answer below:

The maximum amount of carbohydrate that can be burned during exercise from a single carbohydrate source (such as glucose) is about 1 gram per minute or 60 grams per hour. The transporter in the small intestine that is responsible for absorbing that carbohydrate becomes saturated. Consuming more than 1 gram per minute from one carbohydrate source does not raise the rate of carbohydrate oxidation and increases the risk of gastrointestinal distress.

By consuming multiple carbohydrates that use different intestinal transporters, the total amount of carbohydrate that can be absorbed and burned is increased. When glucose and fructose or glucose, fructose, and sucrose are ingested together during exercise at a rate of 2.4 g per minute (144 g per hour), the rate of exogenous carbohydrate oxidation can reach 1.7 g per minute or about 105 g per hour. Drinks containing multiple transportable carbohydrates are also less likely to cause gastrointestinal distress since they are absorbed quickly.

Water absorption is also enhanced when sports drinks include two to three different carbohydrate sources (glucose, sucrose, fructose, or maltodextrins) compared to solutions containing only one carbohydrate source. The addition of a second or third carbohydrate activates additional mechanisms for intestinal transport and involves transport by separate pathways that are noncompetitive.

The series of studies conducted by researchers at the University of Birmingham have shown that consuming between 1.8 to 2.4 g of carbohydrate per minute (108 to 144 g per hour) from a mixture of carbohydrates increases carbohydrate oxidation up to 75 to 104 g of carbohydrate per hour.

When providing recommendations for carbohydrate intake during exercise, I take into account the athlete’s body weight. To maximize carbohydrate oxidation and improve performance, endurance athletes should consume ~1 gram of carbohydrate per kg of body weight per hour from either carbohydrate-rich fluids or foods providing a mixture of carbohydrates. Athletes should individually determine the optimum amount of carbohydrate to enhance their performance.

Miles of smiles,
Ellen

Sports dietitian and Skyline Addict

[lilbitmo]

Ellen,

Are you familiar with Hammer Nutrition products?
I use their "Perpetuem" and their gels.
Both have "Long Chained Maltodextrin" in the Perpetuem and "Maltodextrin, Glucose Polymers" in the gel - what's your take on these?

I also consume trail bars that have sugars in them but rarely eat any other food as I like the fact that these are absorbed into my system quickly and use the lest amount of "hydration" to process, as I've been told and have read that eating whole foods tends to take "water/hydration" away from the muscles and put it into the digestive track or the water you are consuming is going more towards digestion instead of hydrating the muscles as needed.

I have found that I do better on hikes when I consume these products and limit the amount of "whole foods". At some point (long hikes) I have to consume more than just powdered products and bars as my digestive track longs for some substance and so does my brian but I've had good luck with doing the powders and little food.

Do you suggest I add something like a "bread" or anything else that will increase my "charbohydrate absorbtion rate" and allow more fuel into the muscles for a "more sustained balance burn on the longer hikes"?

I also have noticed that on hot days the amount of water I take in get's limited by the heat as my body starts feeling "bloated" and it will not absorb any more water if I drink too much, too fast. Any suggestions for that as well?

I also do "Endurolyte powder" which are a mixture of Sodium, Chloride, Calcium, Magnesium , Potassium, Vitamin B-6, and Manganese to keep my electrolight in balance.

[Ellen]

Howdy Patrick,

These are all great points of discussion for my first Skyline trip on Saturday HA, HA, HA -- I knew I'd find a way to slow you down enough to hike with you

In brief, when I'm hiking uphill, I limit my intake to sports drinks and carbohydrate gels as these are rapidly absorbed. This way my gut isn't competing with my muscles for blood supply. I save "real food" for the summit. Some hikers do just fine with real food while climbing.

When working out in the heat and trying to fuel/drink, your skin, muscles, and gut are all competing for blood. This is why you're having issues trying to drink enough in the heat. You may benefit from using a different sports drink.

I am not a fan of Hammer products (will explain why on the hike) but have worked with athletes who do well with them. My job is to help athletes refine and optimize their fueling during training as well as competition (or major hikes). As you know from your own experience, athletes can meet their fluid, carbohydrate, and sodium goals in a variety of ways.

I think you could increase your carbohydrate and fluid absorption by switching to Cytomax, PowerBar Endurance, or Gatorade Endurance and changing your brand of gels. You may want to test other products down the road but stick with your regular fueling and hydration routine for Saturday.

Miles of smiles,
Ellen

[magikwalt]

In reading the various manufacturer's claims it appears there is a split between the simple sugar users and the maltodextrin folks. There is at least one who says you can't mix the two together. I don't know the science on it but I agree with Ellen when she says the most important part is finding a recipe that your stomach tolerates well. I can drink chocolate milk and hit the trail without bother while one of the other guys turns pale just watching me drink it.

I read the research on multiple sugars helping to increase both the amount of carbs delivered and fluid absorbed. If multiple types of simple sugars work fast by using seperate paths does the same hold true for the maltodextrin?

Saturday morning I am going to be adding one new item to my mix. Skittles. I'm looking for a tart taste to counter the Gatorade and add more carbs for fuel. After watching the effect they have on my grandkids I may start running shortly after ingesting them. Of course I may start screaming as well.

[Ellen]

Howdy Walt,

Maltodextrins are long chains of glucose molecues hooked together. In effect it's like consuming just glucose when maltodextrins are the sole carbohydrate source in the sports drink or gel.

Gu and Powerbar gels contain maltodextrins and fructose. This combination has been tested by the University of Birmingham researchers and works well, as does the combiantion of glucose and fructose.

I've heard from triathletes I work with that Hammer products "don't play well with others." These folks developed gut distress when trying to add a different gel or sports drink. That's the first reason I dislike Hammer products. Second reason -- they don't have multiple transportable carbohydrates. Third reason -- sodium is the primary electrolyte lost in sweat and Endurolytes have very little. To get the amount of sodium on average lost in a quart or 2 lb of sweat (800 mg), you'd have to take TWENTY capsules since each contains only 40 mg of sodium.

In reading the various manufacturer's claims it appears there is a split between the simple sugar users and the maltodextrin folks. There is at least one who says you can't mix the two together. I don't know the science on it but I agree with Ellen when she says the most important part is finding a recipe that your stomach tolerates well. I can drink chocolate milk and hit the trail without bother while one of the other guys turns pale just watching me drink it.

I read the research on multiple sugars helping to increase both the amount of carbs delivered and fluid absorbed. If multiple types of simple sugars work fast by using seperate paths does the same hold true for the maltodextrin?

Saturday morning I am going to be adding one new item to my mix. Skittles. I'm looking for a tart taste to counter the Gatorade and add more carbs for fuel. After watching the effect they have on my grandkids I may start running shortly after ingesting them. Of course I may start screaming as well.

A tall, muscular Marine running and screaming on Skyline -- oh dear

Miles of smiles,
Ellen

[Hikin_Jim]

I can see it now on Skyline on Saturday:

Old Timer: Hi, are you a fellow Skyline addict?
Newbie: Oh, no, I hate hiking.
Old Timer: What?! Then why on earth are you here?
Newbie: Well, I'm a professional athlete, and I hear there will be a really good nutrition lecture...

Wow, is that trail ever going to be crowded this Saturday!

[Ellen]

Howdy Jim



Well, talking about something does help pass the time I've also been known to sing: "The hills are alive with the sound of music..." and "Miles from nowhere, guess I'll take my time. Oh yeah. Look up at the mountain, I have to climb ..."

I hope to see you at the upper tram to congratulate you in person on the birth of your darling daughter.

Miles of smiles,
Ellen

[magikwalt]

Oh Ellen...Where was that info before I used the Hammer Perpetlum for carbs and Gatorade for hydration. I heaved up most of it right after tombstone rock (5100ft) and ZippetyDude found me laid out on the traverse totally racked with body cramps. My worst day ever on Skyline.

[Ellen]

Howdy Walt

Yikes -- that sounds awful Was that the same day that you water stash was stolen and you had run out (due to sharing with another hiker)? If so, I remember that trip report. Z unfurled his cape and got you to the Notch.

On my hottest Skyline hike ever (don't ask), I almost couldn't get out of a stall in the ladies room at the upper tram station due to full body cramps. I had visions of the tram employees calling for the jaws of life to extract me

Miles of smiles,
Ellen