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McNett – Back Country Nutrition

Backcountry Nutrition

What’s necessary for extended hikes and scouting:

• Endurance
• Strength
• Speed
• Mental Clarity
• Dexterity

All of which are affected by nutrition.

When any of the above are impacted, you can quickly turn into a liability for the rest of your group. That said, keeping our body in proper working order and maintaining our speed, strength, endurance, mental clarity and dexterity are essential, which means maintaining proper backcountry nutrition is extremely important.

Caloric Needs
An average person on an average day burns around 2500 calories. A backpacker carrying 50 pounds for 6 hours over level terrain may burn 4000 to 5000 calories. Add elevation gain and a few more hours and the count raises to 6000 to 8000 calories.

A calorie is simply the amount of energy that foods will produce in the human body. The calories in our food come from three sources: carbohydrates/sugars, proteins and fats. Carbohydrates and proteins provide us with 4 calories per gram. Fats provide us with 9 calories per gram. While fats are much more energy-rich, than carbohydrates or proteins it does not mean that we should only consume fats as we will find out below.

Carbohydrates
Carbohydrates are our main source of fuel for energy in the backcountry. Our ability to sustain vigorous activity/exercise is directly related to carbohydrate stores. Many times, when sprinting, climbing or strength training, carbohydrates will contribute to 100 percent of energy needs.

Carbohydrates are stored in the body as glycogen. Each gram of carbohydrate is stored with 3 grams of water, which means we can only store so much. Glycogen is typically stored in the muscles where it is used for muscular activity (i.e., endurance and/or high intensity activity) and in the liver to maintain glucose levels for the brain. The brain does not store glycogen and relies on these stores in the liver for its fuel source. Basically what happens is, after you eat, enzymes in your digestive system begin to break down the carbohydrates and create glucose.

The body will use some of the glucose produced to fuel its cells and body systems by transporting it through the bloodstream (approximately 120 Calories of glucose are available within the bloodstream at any given time).
As the amount of glucose in your blood begins to rise, insulin is released and directs the cells in your body to remove excess glucose from the bloodstream and store them in your muscles and liver. As it’s being transported to the liver and muscle tissues, glucose molecules bond to one another to create glycogen. Think of glycogen as back-up energy for when our body needs it. Your muscles can store about 1400 calories and the liver can store about 400 calories. Endurance training increases glycogen storage capacity. That said, a little bit of endurance training will certainly help with glycogen storage and will give you added back-up energy storage.

On average the body stores enough glycogen to fuel moderate effort for 90-minutes in a trained individual. However, increased workout intensity can deplete oxygen in as little as 30-minutes.Which is important to note since carbohydrates contribute to a majority of our energy needs. The greater the intensity of exercise and heart rate, the more carbohydrates burned. Remember, these carbohydrates are the primary fuel for high intensity activities as well as proper brain function.

Carbohydrates not only fuel exercise and brain function, but they are also essential for maintaining body temperature in the cold and for shivering. Low levels of carbohydrates impair thermoregulation and increase the risk of hypothermia.

The goal is to eat frequently and to avoid dips in blood glucose levels. We digest and absorb, on average, 1 ounce of carbohydrate every minute. That said, we need about 60 grams of carbohydrates (240 Calories) per hour, which means that ideally you will fuel up every 15 minutes with about 15 grams (60 Calories) of carbohydrates.

Once depleted, the body turns to our fat reserves for energy.

However, if carbohydrate storage sites are filled to capacity the body will begin to burn more glucose rather than fat as a last resort. And if glucose continues to enter the bloodstream, fat cells will then start the process of storing energy and you start the process of getting fatter!
In addition, the brain runs exclusively off of carbohydrates, which means carbohydrates are essential for proper brain function and mental clarity.

Fats
Muscles require a mix of carbohydrates and fats for energy. Carbohydrates burn off fairly quick and need to be replenished constantly, while fats (a more concentrated energy source) burn slow and continuous maintaining a slow, constant flow of energy.

There are two types of fats: saturated and unsaturated. Saturated fats are usually preferred in the backcountry because they tend to be solid and tend not to go rancid. However, saturated fats do not travel as well through the vascular system and are typically associated with higher levels of cholesterol. They are easier to carry into the backcountry and less likely to go rancid, but they are typically associated with higher levels of cholesterol and should be consumed in limited quantities.

Either way, the body needs fat. It’s a major energy source, helps you absorb certain vitamins and hormones are also synthesized from fat, so it is a very important source of nutrition.

Fat requires oxygen in order to breakdown properly, which should be taken into consideration at higher altitudes that are more oxygen deprived. At higher altitudes you may want to have a greater reliance on carbohydrates.

Fat does not metabolize as quickly as carbohydrates so during high intensity workouts the body can’t keep up, resulting in fatigue, weakness, and mental confusion. This is typically called hypoglycemia (low blood sugar).

Fat is our endurance energy, and carbohydrates are for short-term power. A bi-product of the digestion process is the generation of heat. As your body breaks down and digests fats, heat is created. That said, it’s a good idea to consume a food or beverage high in fat before bedding down for the night in cold environments. Add butter to hot chocolate before going to sleep to help stay warm at night.

Endurance athletes are good at burning fat as fuel over a long period (well-developed fat metabolism) of time allowing them to rely less on carbohydrates, however, carbohydrates are still essential for and remain the primary energy source for muscle contraction.

Fat should contribute to 25 percent of core calories. Carbohydrates should contribute to 65 percent. Proteins should contribute to 10 percent.
While Protein does Provide Calories, its Primary Function is for growth, maintenance and repair of muscles, bones, organs, hair and nails. This is why protein needs are far less than fats and carbohydrates.

Vitamins and Minerals
6 types of nutrients in foods: carbohydrates, fats, proteins, vitamins, minerals and water. Only carbohydrates, fats and proteins can provide energy/calories. Vitamins, minerals and water provide no calories but they are essential in our ability to use the calories.

Vitamins and Minerals are essential for the breakdown of carbohydrates and fats. We eat foods. Next, the food is converted into chemical energy within our muscle cells with the help of vitamins and minerals and then transformed into mechanical energy for the physical exercise.

In the Nutritional World:

Energy = Calories
Unprocessed foods = good
Processed foods = bad

Why: Nutrient destruction happens to all fruits and vegetables that are not freshly prepared. Excessive heating and cooling processes, which are required in order to give processed foods extended shelf lives, greatly diminishes nutrients. Blanching vegetables before they are packaged causes water-soluble vitamins like vitamin B to fall out. Milling grains for breads causes the husk to fall off, which stores most of the valuable nutrients, etc. etc. Trans-fats, sodium and nitrates are also typically added to processed foods to boost flavor and increase shelf life.

Food Groups
The food groups (2-3 servings from each group is ideal):

Dairy: Milk (cup), yogurt, cheese (1 oz), cottage cheese

Vegetables: Fresh at home, dehydrated in the backcountry, salsa

Whole Grains/Starch: Whole grain bread and cereal, brown rice, potato, pasta, corn, tortillas

Protein: meat, chicken, turkey, eggs, fish, beans, peas, lentils (1 oz. of meat or fish and each half cup of legumes = 8 grams of protein)

Fruit: fresh or frozen at home; dehydrated in the backcountry

Fat: Unsaturated ideal: olive oil, canola oil, seeds, olives, avocado, nuts

We’d love to hear what you’re bringing into the backcountry…

This post is brought to you by McNett. McNett offers products for maintaining, repairing, and waterproofing gear and clothing, and water purification, as well as microfiber towels and tactical products including lens cleaner and anti-fog, survival products, and Camo Form camouflage wrap.

www.mcnett.com

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13 Responses to “McNett – Back Country Nutrition”

  1. Steven says:

    A great primer on exercise physiology and nutrition however there is one thing I’d like to help clarify in the carbohydrates section:

    “Once depleted, the body turns to our fat reserves for energy”

    The source where we get our energy from varies based on intensity and duration of the exercise. Fat burning requires an input of carbohydrate and our bodies do not usually completely run out of carbs.

    Depending on the activity, we might get more energy from carbs than fat or vice versa in between the two extremes, for example sprinting and marathon running at mile 16.

    While usually it is true that during exercise we start off by burning carbs and switch to fat as our intensity decreases, duration increases, and oxygen becomes available, that is not always the case. For example, if your workout starts off with an hour long jog and you finish with sprints and weight lifting, you actually got more energy from fat at the beginning of your workout and when it comes to sprints and weights at the end, you got more energy from carbs

    sources:

    http://books.google.com/books?id=L4aZIDbmV3oC&pg=PA194&lpg=PA194&dq=fat+burns+in+a+carbohydrate+flame&source=bl&ots=WlvVrdIe0L&sig=RpcGbagctZLLKM5KlhEb06rZEOI&hl=en&sa=X&ei=SawcU_biHcuOqAHI34CQDA&ved=0CEcQ6AEwBQ#v=onepage&q=fat%20burns%20in%20a%20carbohydrate%20flame&f=false

  2. Charliemike says:

    Great bit of info! Also, heart rate plays a large role in how your body will be trained and what types of fuel your body will use. For example, walking for an hour will place your heart rate in a much different zone than If you were doing doing 30 second sprint intervals on a treadmill. And everyone’s heart rate and zones are specific to the individual depending on your level of fitness. And then obviously, dependin on what zone your hert rate is in, you will either burn fat or carbs. Joel Jamieson at 8weeksout has a lot of great videos on this stuff and different methods of conditioning on his site and he trains a lot professional athletes with this from MMA guys to Olympic weightlifters. Great post!

  3. Canadian says:

    This article is full of the same garbage that have been pedaled as nutrition info for the last 30 years. FAT is what your body needs. Unfortunately many of us are addicted to complex carbs (which are actually chains of sugar), and our bodies don’t break down fat as readily as they should. Cabs should make up 1/3 of what we eat- especially in the backcountry.

    Once you feed your body with more fats (not fried foods, but animal fats), and don’t give in to wanting a loaf of bread on the trail- your body will process fat at a steady rate, more efficiently, and you won’t fell the “I’m super full” after a meal, followed by “I’m starving and dizzy” 4hrs later.

    Protein, and fats, including nuts, oils, and meat- should make up the bulk of your food on the trail. Dried fruits and vegetables should make up the rest- and dark chocolate (NOT milk chocolate) are a good way to add some flavor and a quick sugar boost, but only in small quantities.

    • Canadian says:

      I should also add the fact that many more calories are in unprocessed animal fats than in complex carbohydrates by volume. You can carry more calories with less weight in butter, cheese, jerky, and nuts- than in bags of instant oatmeal and whole wheat sandwiches.

      • Steven says:

        Can you post up primary sources corroborating what you’ve just stated?

        Fat burning requires an input of carbohydrates. It is common knowledge. Run low on carbs and fat burning gets impaired. A pound of fat in the human body is roughly 3500 calories, but burning it requires carbs and the body simply does not store much of it.

        The body cannot break down fat to turn into carbs. It can however break down protein to turn into carbs but that is not an ideal situation for obvious reasons.

        Notice that marathon and ultra long distance runners are taking carbs during the races and carb load; some of these events have a lot at stake for participants. They are not doing it wrong.

        Carbs, not fat, are the limiting factor here. Endurance training, etc are all geared towards training the body to burn fat as soon as possible to SPARE glycogen.

        So post up your sources. They need to be academic otherwise it is garage science.

        • Canadian says:

          Another study- The abstract comes up first, click on “full text” for the whole deal.

          http://jap.physiology.org/content/111/1/108.full.pdf+HTML

          The study states:

          “Interestingly, a fat-rich diet elicits significant IMCL utilization during exercise in type IIa fibers, which otherwise, do not exhibit exercise-induced IMCL breakdown in young, healthy male volunteers. Furthermore, during training on a hypercaloric HFD, the capacity for muscle glycogen utilization in endurance exercise is well maintained, probably because adequate dietary carbohydrate supply prevents a training-induced drop of muscle glycogen content.”

          Yes this is a hypercaloric diet, however the diet was 50% fat, and I am not talking about reducing overall calories for weight control, I’m referencing what is basically the recruitment of ingested fats vs sugar. You certainly still need sugar, just not in the high quantities many people think you do.

          After the summit push, or at the end of the hike, go ahead and eat some sugar, just don’t fuel yourself with oats and bread all day to get there.

        • Canadian says:

          I will note that the study I posted utilized 40% carbs which is slightly higher than the 33% (1/3rd) I stated above. I have found other literature that recommends approximately 1/3rd, I just can’t locate it now. My body runs well on approx 1/3 carbs- everyone will be slightly different.

    • gilk10180 says:

      Thank you for writing this. Fats are simply amazing even for endurance athletes. I preach all the time to our guys that fats are not to be feared and the junk science that came out of the 7 countries study, is simply that, junk science.

      • Canadian says:

        Agreed.

        Correlation does not equal causation, and although overall calories do effect the amount of energy the body stores- the type of food we ingest severly influences how the body regulates energy storage.

        That 7 countries BS has probably killed many more people than cigarettes and land mines.

  4. Canadian says:

    http://uctscholar.uct.ac.za/PDF/91334_Havemam_L.pdf

    First one I could find. Basically it’s a study of pre-race loading techniques. Although there is some variation in RER phenotypes, the brakedown shows that pre-race loading with high fats, then one day of carbs, allows the body to efficiently process fats. This allows better glycogen storage. There was a minimal effect on sprint times (not enough for a major statistical conclusion), but during endurance climbs there was better performance.

    I realise this is not about steady fat intake, but it does show the ability of the body to modify it’s ability to oxidize fat with some training. I will look for some of the other sources I’ve used, but I keep coming up with studies about weight loss, which is not the current discussion.

    I will note that I have experienced this myself, and practice it on multi-day excursions and military operations- however I realise that my experience is anecdotal and does not make a scientific case.

    • Steven says:

      Thanks for posting up!

      The research into fat intake and exercise physiology is intriguing and I plan on doing some reading and brushing up on the subject. I knew about several studies suggesting that increasing fat intake (but not necessarily total calorie consumption per day) increases fat utilization but I wasn’t aware of that research.

      I’d like to apologize for my comments to you, clearly you know about the subject and have done the leg work. I was just a little rattled/offended by your earlier post regarding carbs. Possibly we were thinking about it in different ways but I agree that more calories/carbs than are needed or at inappropriate times is not ideal.

      • Canadian says:

        Steven,

        No problem, no offense was taken. I agree that it can be a contentious subject, and the first time I heard about any of this I thought it might be a fad.

        After working with variations myself, I find it to work quite well- everyone will be a little different in how they respond to certain foods though.

        Specifically in the backcountry, including alpinism, climbing, and military training- I will carry moderate to low sugar trail mix (not full of candy, sweeteness from dryed fruit), in the winter I’ll take some sausage, in the summer pepperettes and jerky. When we stop I’ll take a couple of bites, and I generally feel pretty steady al day. I also find it very useful to bring butter (not margarine). I’ll throw pats of it in with whatever rations I’m eating (usually dump out half the serving of oatmeal if I have to eat that), and I find that I don’t get the miserable starving feeling or hunger headaches.

        Best of luck with your research!