The body has a remarkable reserve capacity of nutrients, minerals and vitamins to buffer against short-term deficiencies or fluctuations in your diet. But long-term neglect will take a toll on your health, your performance, your enjoyment of your wilderness experience, whether backpacking, canoeing or skiing. For backpackers, it is critical to consider how to optimize nutrient quality, while minimizing the weight/bulk of both the food and fuel carried.
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OVERVIEW:
How many Calories do I need?
If your load is less than 15% of your body weight and terrain is gentle, your caloric needs are not significantly different from normal (i.e, 2500-3500 Calories for active females, 3000-4000 Calories for active males). If, however, you are carrying 25-35% of your body weight over difficult (uneven/steep) terrain, you will need extra calories (500-1000, give or take). Body reserves will contribute a significant portion of your energy needs during the first few weeks of a thru-hike, but as bodies become leaner, dietary intake becomes more crucial.
How many pounds of food should I take?
If you choose a balanced diet with 30-40% fat, pack 1.5-2 pounds dehydrated food/person/day for easy-moderate hike; 2-2.5 lbs./person/day for moderate to difficult conditions.
For a long duration hiker, boost the fat to 35-40% by selecting foods that are calorie dense (that is, above 5.0 Calories per gram, See Fat), which means choosing high fat foods. Besides keeping your pack weight down, your food will taste better and your breakfast will hold you longer since fat slows down digestion, giving you a more even distribution of fuel being absorbed. (Note that the recipes are given with a "Plus Fat" option for long duration hikers.)
Isn't 30-40% fat too high?
Fat and carbohydrate, not protein, are the preferred fuels for muscle. Don't fall into the trap of thinking, Carbohydrates are good and fats are bad. A balance is necessary to achieve maximum performance over the long haul. Protein is important for building muscles and regulating the chemical processes within the body, so protein is normally not a significant fuel source (5-10% at most)].
Fat supplies 9 Cal/gram, over twice as many Calories as carbohydrate or protein, which supply 4 Cal/gram.
1 teaspoon of sugar (carbohydrate) weighs 5 grams = 20 Calories.
1 teaspoon of butter (fat) weighs 5 grams = 45 Calories.
Same weight, but fat can supply over twice the energy carbohydrate (or protein) can.
But isn't fat bad for your health?
Not when you are burning off the calories as fast as you take them in
(i.e., weight holding constant) and you are getting plenty of exercise.
See Fat.
How can I avoid "hitting the wall"?
"Hitting the wall" is due to depletion of muscle glycogen/carbohydrate. You feel like someone has put lead in your boots and it is major anguish to move. You've just run out of carbohydrate stores and the muscle has to rely solely on fat for energy. Fat requires oxygen, so you can only move as fast as oxygen gets supplied to your muscles, and there's no backup from carbohydrates. CURE: eat/drink carbohydrates. But better yet, PREVENT it from happening by feeding your body small frequent doses (25-50 grams every few hours) of carbohydrates throughout the day, thus conserving your stored carbohydrates. (Refer to Table 2 below, Trail Snacks.)
To maintain energy levels over the long haul, snack on carbohydrate AND fat. Like M&M peanuts, GORP, PopTarts, crackers or granola bars. AVOID excessive amounts of the high sugar snacks, especially just before beginning your day--they may cause insulin levels to rise, which will work against you, locking your fat in storage, rather than making it available to your muscles. Proper training will make your muscles more efficient fat burners, thereby sparing glycogen.
OVERVIEW of Carbohydrates: --> 4 Calories/gram
Glucose--blood sugar; preferred fuel for brain and muscles during high intensity exercise
Lactic Acid--half a glucose molecule, produced when oxygen supply is limiting and glucose cannot be completely combusted; lactic acid can be recycled back to glucose in the liver, thus restoring blood glucose levels after exercise. Training is critical to get plenty of oxygen to your working muscles and prevent lactic acid from forming in the first place.
Glycogen--"animal starch"; many glucose molecules joined together; mainly stored in liver and muscles. Glycogen is the competitor's edge--the source of energy for the last sprint up "Heartbreak Hill". Even though backpackers aren't likely to be sprinting, if you're in for a 20 mile day, glycogen may make the difference between 10 hours or 14 hours on the trail. As blood glucose levels fall, the liver will share its supply with the rest of the body, thus sustaining blood glucose levels, thereby keeping the brain happy. (Remember glucose is the brain's preferred fuel.) Muscles don't share their glucose with other tissues. It's not that they are selfish. They just can't--they don't have the necessary enzymes to release glucose back into the bloodstream. So for glycogen, once stored in muscle, always in muscle.
The size of the storage depot in the liver is nonnegotiable (predetermined by size, heredity, and all that--usually about 500 Calories), but the amount of glycogen stored in the muscle IS negotiable. With training and proper diet, the serious athlete can increase glycogen stores in the muscle from 500 Calories to 1,500-2000 Calories. Practically speaking, how much energy is that? Enough to last about 2 hours hiking up the Cathedral Trail of Mt. Katahdin. You may know when you "Hit the Wall''--when your glycogen stores are depleted and your muscles have to rely more heavily on other fuels. Fortunately, "hitting the wall" is not the end of the trip, but it does require some adjustment. Not all your energy comes from glycogen. There are plenty of fuel resources--branched chain amino acids, glucose which is being made in the liver from metabolic "left-overs" like lactic acid, but the main fuel supplying exhausted muscles is fat. Maligned, unappreciated Fat. When you think you can't go another step, Fat may get you home tonight. You just have to slow down to allow oxygen to reach your "burnt out" muscles.
THE STRATEGY OF SNACKING
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OVERVIEW:
GLYCOGEN is the first fuel to become depleted.
To avoid glycogen depletion, snack frequently (20-30 grams/hour) throughout the hike, and eat a high carbohydrate meal within an hour after quitting for the day.
DON'T eat a high sugar snack just before exercise, unless it is combined with other low sugar foods.
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Should I carbohydrate load?
No, there's no need to carbohydrate load. But yes, there is every reason for you to maintain your glycogen stores at optimum levels. If you don't, you'll hit the wall, or worse, "bonk" (run out of both liver and muscle glycogen stores).
Suggestions to sustain glycogen through weeks of endurance exercise.
1. Snack, Snack, SNACK!
Throughout long treks, Munch. Because BOTH fat and carbohydrates are being burned in active muscle, the ideal way to maximize relative fuel consumption is to keep eating a mixture, but carbohydrates are especially critical during exercise. The body has an ample supply of fat stored up, so even if you don't eat any fat, there's plenty available in the bloodstream, being delivered from storage. Not so with carbohydrates. Storage is limited. See Table 2 below for Snacks ranked by carbohydrate content.
2. REST!
Give muscles a chance to replenish their carbohydrate stores. It takes several days to fully replete stores after they are exhausted/depleted. On a long trek, you may find your energy level flagging earlier and earlier with each passing day. Feeling tired, weak, anemic. You don't have the same stamina. It's likely not because you are suddenly iron deficient, but rather because you are running out of stored carbohydrate. Plan a day of rest following a particularly long grueling day and eat plenty of complex carbohydrates (i.e., whole grains, starchy vegetables). [Notice how many through-hikers do just the opposite. They eat high carbohydrate meals on the trail, then bee-line to town to gorge on a pint of Ben and Jerry's ice cream and a dozen donuts after single-handedly inhaling a large pizza with everything on it. Where does all that fat go? It's NOT replenishing depleted glycogen stores (humans can't convert fat to carbohydrate effectively). If it doesn't go straight through you (diarrhea), some of the fat goes to replete the fat stores in the heart and muscle, but most of the excess goes right back into storage to be lugged around a few more miles.]
3. TIMING
Eat frequent carbohydrate snacks, especially during and immediately after a hard workout (15 minutes to 1 hour after quitting for the day, so keep your dinner menu simple). During the day, about 20-30 grams of carbohydrate per hour is a reasonable goal. 20 grams for easy hiking; 30 grams for more challenging terrain. And the sugar can come from complex carbohydrates (="starch"/ "whole grains"/"high fiber" foods), which are better nutrients all around. Complex carbohydrates release sugar over a longer period of time, rather than getting one big dose all at once. A second benefit of complex carbohydrates is that they are more likely to supply the B vitamins and minerals you need. (Refer to Table 2, Trail Snacks, below.)
4. Never eat a high sugar snack just before exercising.
Insulin, a hormone released when sugar is eaten, stimulates cells to absorb glucose from the bloodstream, thus causing blood glucose levels to fall. If you then begin to exercise, glucose levels will further plummet, thus decreasing your endurance. A drink of water or milk would be better than drinking a sugar-laden soda just before you exercise, since the sugar will cause you to run out of energy faster. If you must mainline sugar, eat it in small doses during or after exercise, but not before!
Hypoglycemics/diabetics: A special alert: a high carbohydrate
diet (70:15:15) can work against you. If you're trying to preserve your
glycogen stores for the long day ahead, insulin says, " Burn carbohydrate,
not fat", but you really want to preserve that glycogen as long as you
can. What to do? Avoid eating excessive amounts of simple sugars, so insulin
won't be released. Spare glycogen by eating complex carbohydrates (starches)
or small quantities of combination foods--foods that contain protein, sugar
and fat (i.e., cheese and crackers or a Pop Tart), so that absorption is
delayed and insulin response is lower.
The Perfect Food--What is it?
There is no perfect food. In order to get a balanced diet providing adequate minerals and vitamins, select a variety of foods as suggested below.
Note to the Ultralights/Minimalists: Sure you can get by without a stove. No morning coffee, no hot soup on a rainy day. Just cold cereal, chips and dip, tabouli, cheese and sausage. . . and frequent trips to town to gorge yourself. There are plenty of food choices that require no fuel/preparation, but seriously consider what you are trading off. Are you carrying heavier (hydrated) foods in place of 2 pounds worth of stove + fuel? Are you adding 5 miles per day to your itinerary just to access food? For short term hiking, it is easy to plan an appealing menu that is light weight and requires no stove. For months on the trail, try to imagine what you will feel like when you try to swallow the 1,346th Mocha flavored energy bar. But for the insistent, the Shopping List below allows enough flexibility that you should be able to plan a reasonably varied, nutritionally adequate diet, even without a stove. Just select foods within the same category. Example: Since you cannot prepare rice, Ramen or couscous, buy an extra 5 pounds of bread, crackers, cereals and chips.
Table 1. THE SHOPPING LIST
The following Shopping List will provide approximately 75,000 Calories--enough
for 2 people for 7-12 days, depending on elevation change, climate, load
in their pack, trail conditions, and number of miles covered each day.
Expect to burn more Calories after about six weeks on the trail. Your body
eventually adapts to the added stress by "turning up the heat." On a through-hike,
muscle protein gets turned over faster, more blood cells and new capillaries
are being made, and you will feel voraciously hungry. Well into the through-hike,
75,000 Calories may only be enough for ONE person for 12 days. See Recipes.
FOOD | QUANTITY (lb.)
Pack Light 55:30:15 |
QUANTITY (lb.)
Ultra Light 45:40:15 |
COMMENTS for Ultra Light |
---|---|---|---|
HIGH FAT FOODS
Oil/margarine |
0.5 |
0.5 |
Oil is more calorie dense than margarine |
HIGH FAT/HIGH PROTEIN
Seeds/nuts Peanut butter Cheese |
2.0 1.0 2.0 |
2.0 1.0 1.0 |
Buy dried cheese |
HIGH PROTEIN
Beans/legumes Jerky/sausage Dried fish/meat Instant Breakfast |
1.0 2.5 1.0 0.0 |
2.0 1.0 0.0 2.5 |
(vitamin/mineral rich) |
FOOD | QUANTITY (lb.)
Pack Light 55:30:15 |
QUANTITY (lb.)
Ultra Light 45:40:15 |
COMMENTS for Ultra Light |
HIGH CARBOHYDRATE
Drink mix: cider, gatorade Pudding mix Soup/Gravy mix Cereals (hot or cold) Rice or couscous Ramen noodles (10 pkgs.) Potato flakes Baked cookies/breads Crackers/chips Granola bars/PopTarts Flour/baking mix Dried vegetables Dried fruit Candy |
1.0 2.0 1.0 5.0 2.0 2.0 1.0 5.0 2.0 2.0 1.0 1.0 3.0 2.0 |
2.0 1.0 1.0 2.0 2.0 2.0 0.0 2.0 3.0 4.0 1.0 1.0 2.0 2.0 |
Cream/cheese-based mixes
Dry mix (eg. Trail Brownies)
Include Banana Chips
|
Total weight (75,000 calories): 40 lbs. 35 lbs.
Fuel required for either category: less than 4 lbs. (2 quarts)
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Training.
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Table 2. TRAIL SNACKS
Portions Providing 15-30 grams carbohydrates
FOOD | QUANTITY | CALORIES | CARBOHYDRATE
(grams) |
FAT
(grams) |
PROTEIN
(grams) |
---|---|---|---|---|---|
HIGH Carbohydrate (>90%
Carbohydrate)
Gatorade Hard candy *Dried apples *Raisins *Prunes *Dried apricots *Dried figs *Fruit leather |
1.5 Cups 1 oz. 7 pieces 2 T (25 g) 5 pieces 10 pieces 2 pieces 1 oz. |
75 106 108 75 100 83 95 100 |
21.0 27.8 29.7 20.0 26.3 21.6 24.5 24.2 |
0.0 0.0 0.1 0.1 0.2 0.2 0.4 0.8 |
0.0 0.0 0.4 0.8 1.1 1.3 1.1 0.3 |
MODERATELY HIGH Carbohydrate
(70-90% Carbohydrate) |
Quantity | Calories | Carbohydrate
(grams) |
Fat
(grams) |
Protein
(grams) |
*Pretzels
*Fig bars *Graham crackers *Plain bagel *PopTart |
1 oz.
2 bars 4 squares 1/2 piece 1/2 tart |
108
106 120 82 105 |
22.5
21.2 22.0 15.5 18.0 |
1.0
2.0 2.0 0.7 2.5 |
2.6
1.0 2.0 3.0 1.0 |
MODERATE Carbohydrate
(40-70% Carbohydrate) |
Quantity | Calories | Carbohydrate
(grams) |
Fat
(grams) |
Protein
(grams) |
*Saltines
*Granola bar *Peanut butter Granola bar *Cracklin' Oat Bran *Natr. Valley G’ola *Tropical Trail Mix *Stoneground crackers M&M plain M&M p'nut Snickers *Tortilla chips *Ritz crackers *Better Cheddars *Banana chips *Bagel + 1 T p'nut butter |
10 crackers
1 oz. 1 oz. 1 oz. 1 oz. 1 oz. 8 crackers 1/2 pkg (.88 oz.) 1/2 pkg (.85 oz.) 1/2 bar (1.1 oz.) 1 oz. 8 crackers 20 crackers 1 oz. 1/2 piece |
120
128 128 110 126 115 140 115 140 138 142 140 140 147 176 |
20.0
19.3 17.8 19.4 18.9 18.6 18.0 16.3 14.5 18.4 17.8 18.0 16.0 16.6 8.9 |
4.0
4.7 4.9 4.1 4.9 4.9 6.0 5.3 6.6 6.8 7.4 8.0 8.0 9.5 8.7 |
2.0
2.0 3.1 2.6 2.9 1.8 2.0 1.5 2.6 2.9 2.0 2.0 4.0 0.7 6.9 |
LOW Carbohydrate
(20-40% Carbohydrate) |
Quantity | Calories | Carbohydrate
(grams) |
Fat
(grams) |
Protein
(grams) |
Peanut butter cups
Trail mix (Nuts/fruit) |
1 piece (0.9 oz.)
1 oz. |
140
131 |
12.9
12.7 |
8.3
8.3 |
3.2
3.9 |
VERY LOW Carbohydrate
(<20% Carbohydrate) |
|||||
Jerky
Dry roasted peanuts Cheddar cheese |
1 lg. piece (0.7 oz.)
1 oz. 1 oz. |
67
170 114 |
2.9
6.3 0.4 |
2.6
13.2 9.4 |
7.9
6.6 7.1 |
*Complex Carbohydrates
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PROPER TRAINING
Do I need to train to prepare for a long distance hike?
Properly trained muscles are more efficient fat burners. If, however, you insist you don't have the time to properly train, give yourself a gentle itinerary the first few weeks you hit the trail. You'll be "On-the-Job" training, whether you had time for it or not.
Because fat is a major fuel source in low-moderate intensity exercise, limited only by the amount of oxygen available, training should maximize oxygen delivery and utilization. The more oxygen, the more efficiently energy is produced. That's what training is all about--how to improve the oxygen delivery system to your muscles.
Endurance training almost doubles the % Calories derived from fat while sugar (carbohydrate) use is cut almost in half. Thus, trained muscles burn a richer fuel mixture (high fat), conserving carbohydrate stores, so you are getting maximum return on your investment--the most Energy for the least amount of weight in your food bag (see Table 1).
So how do I "endurance train"?
Endurance training is different than the aerobic workout typical of a jogger. The difference is a matter of duration, and intensity (or effort) expended in the activity. For long duration exercise, the target heart rate (and VO2 max) will be less than 70% while more intense aerobic workouts are generally above 70%.
Target Heart Rate
In an aerobic exercise program, the target heart rate is the rate that will stimulate changes to produce the benefits of training. Generally 50-85% heart rate reserve is the desired range, calculated as follows:
1) Determine Resting Heart Rate, RHR, by taking your pulse for one minute while at rest (sitting for cyclists, canoers; standing for joggers, hikers . . .)
2) Calculate the minimum (50%) target heart rate by subtracting your age from 220, then subtract your resting heart rate and multiply the difference by 0.5. Add back your resting heart rate.
RHR (220-age -RHR)0.50 + RHR = minimum target heart rate
3) Calculate the maximum (85%) target heart rate by again subtracting your age from 220, then subtract your resting heart rate and multiply the difference by 0.85. Now add back your resting heart rate.
(220-age -RHR)0.85 + RHR = maximum target heart rate
**The Short Cut: you'll know if you are exercising within the 50-85% target range if you can pant out "Old MacDonald had a farm . . " as you hike/jog. If you can't string two words together without gasping for air, you are exercising anaerobically. You are over the maximum target heart rate and should slow down.
The Ideal Training Program
Alternate days of low intensity and high intensity exercise, low intensity one day, followed by higher intensity the next. The purpose of the high intensity exercise is to increase the number and efficiency of the powerhouses (mitochondria). The days you climb three 4000' peaks in a row, you'll be grateful for every minute of high intensity you have ever done. The high intensity workout also allows you to get the maximum benefit for your heart in the least amount of time (eg. a 30-40 minute aerobic workout 3 times a week).
The days you are not jogging/working out at the gym, try to find time to Walk, walk, walk, walk. Preferably with a load on your back. The best training for backpacking is backpacking. Steady daily walking with boots on your feet and a load on your back will train muscles and toughen up feet, hips and shoulders. Aside from aerobic exercise, a strengthening program will reduce risk of injury and increase lean body mass. Knees and ankles are obviously important, but don't neglect the upper body either. [If you need more information, check a local health club or library/bookstore.]
A word of Caution: "Use it or lose it"applies to any training program you undertake. The benefits of crash training (8-12 weeks) will be quickly lost (6-8 weeks) if exercise ceases. Easy come, easy go. The benefits of prolonged training are more likely to be retained.
To summarize,
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