THE COOLANT: WATER!
Water is without debate, the most critical nutrient for your performance and your survival.. What you need when energy flags and your head spins is WATER, WATER, WATER!
How much water do I need each day?
It depends on the temperature, on how hard you're working, on your physiological state--too many variables to give a pat answer. BUT you can know if you're getting enough water. You should need to urinate more than three times a day, and your urine should be pale yellow-to-clear, NOT dark yellow. If in doubt, drink some more. Don't wait until you're thirsty, or you're past the point of "impaired performance." For a ballpark estimate, figure at least 3 quarts/person/day.
Why is water so important?
#1) It's the SOLVENT and reactant for the chemical reactions that keep your muscles moving and your mind alert. Without sufficient water, you dehydrate and collapse.
#2) Water is the COOLANT that carries away the excess heat you generate working so you can maintain the ideal "98.6oF" (or whatever is normal for your body temperature). In short, it does for your body what the radiator does for your car engine. If you can't evaporate off the heat fast enough or are dehydrated, you collapse (heat stroke or heat exhaustion, respectively). In this situation, water outside of the body is almost as important as water inside the body. In very hot climates, make sure you douse your head and torso at every opportunity; wear a wet bandana around your neck. The water outside your body will help as well as the water inside your body to conduct the excess heat away from your body.
Table 5: TREATMENT OF DEHYDRATION
|HEAT CRAMPS||mild dehydration||muscle cramps||rest, ice massage, increase fluid intake|
|HEAT EXHAUSTION||severe dehydration||feverish, dizzy, nausea||cool with ice bath, rest, get to Emergency Rm.|
|HEAT STROKE||severe dehydration||high fever, uncoordinated||cool ASAP (ice bath)|
|HYPOTHERMIA||exposure to cold||depressed body temperature||replace wet clothes with dry|
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What do I do in case of dehydration or heat exhaustion?
In either case, the victim will lose consciousness if the dehydration or exhaustion is severe. Cool their body with wet cloths and fanning (pour your water bottle on them, if necessary, especially on the chest and neck). When the victim is conscious, encourage them to sip water and rest in the shade. Don't allow them to get up until they have consumed at least a quart of water. (Their spinning head should tell them if they haven't had enough yet--drink more.) This is the most common ailment of summer travellers in the Great Southwest. Thankfully, it's easily remedied if you're carrying sufficient water. Once rehydrated, you can go on and finish the 20 miles you set as your goal, but go gently.
Better, however, is an ounce of prevention.
Now that you're properly convinced that water is critical for your well-being, performance and survival, I'm going to flip the message. When it comes to food, leave the water behind. Get the water INTO your water bottle, but OUT of your food bag.
What is the most efficient food --the food that weighs the least but provides the most calories?
As you can see by comparing the values in Table 6, the best you can do is 8.6 calories/gram (vegetable/olive oil). If you carry foods that are not dried, the values can be less than 1.0. For a 50-35-15 diet, try to keep close to the 5 Cal/g, with less than 10% water in the foods you select. Thus, you might choose Pringles over Pretzels, banana chips instead of dried apricots, gingersnaps rather than fig bars. The lower % water, the less unnecessary weight you carry. The higher the caloric density, the more efficient the food weight you carry. Even foods that you consider "dry", like spaghetti or bagels, are likely to carry more water than you expect. Water content and caloric density of Trail Foods are listed in Table 6. The higher the density, the better. It may help you decide what to take, and what to leave home next time you travel.
To reduce water weight even without a food dehydrator:
Table 6: PERCENT WATER AND CALORIC DENSITY IN SELECTED FOOD ITEMS
Items are arranged from most energy dense to least dense in each category.
|FOOD||% Water||Caloric density
|VEGETABLE / OLIVE OIL||0||8.6|
|Pringles potato chips||2||6.1|
|Stoneground crackers||no info||5.0|
|Choc. chip granola bar||5||4.6|
|Granola (Nat. Valley)||4||4.5|
|Quaker 100% Natural||2||4.5|
|Cracklin Oat Bran||4||3.9|
|Whole wheat bread||37||2.5|
|COOKIES & CANDY|
|Reeses peanut butter cups||8||5.5|
|Oreo, dbl-stuffed||no info||5.0|
|Choc. Chip cookies||3||4.6|
|FRUITS & VEGETABLES
|Banana Chips (crispy)||4||5.3|
|DAIRY, MEAT & NUTS|
|Peanuts (honey roasted)||1||6.2|
|Peanuts (dry roasted)||1||5.9|
|Peanut butter (chunky)||2||5.9|
|Powdered skim milk||4||3.5|
|Tuna in water||74||1.2|
|Chow Mein Noodles||1||5.3|
|Ramen Noodles (approx.)||1||4.5|
|Minute Rice (approx.)||8||no info|
*My home-dehydrated fruits and vegetables are dried to the crispy stage, so they contain less than 10% water. Less water means less opportunity for bacterial/fungal activity, and lighter weight for me to carry.
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What happens if I don't get enough salt?
Not likely, if you are eating enough calories to sustain you day after day. (see Table 7.) However, if you drink coffee/caffeinated beverages rather than water/juice, the diuretic affect may induce dehydration and electrolyte depletion. In this case, rehydrate with a quart of dilute Gatorade or another electrolyte-supplying drink. (To get optimum absorption, make a 5% sugar solution, by mixing 2 scoops (4 T) Gatorade per 3 cups water.) If you're thirsty, more caffeine will only make you thirstier.
If you are taking medications, read the labels carefully. Many induce electrolyte loss and therefore you would need to choose moderate- to high-salt foods/drinks, rather than a strictly low salt diet.
What happens if I get too much salt?
Much more likely to have long- and short-term consequences, compromising performance due to the strain of carrying excessive weight, loss of water, fatigue, and for some, increasing their risk of heart disease.
Water follows Salt:
Normally, when too much salt is consumed, a healthy kidney has to work
harder to correct the salt imbalance (get rid of the excess salt). When
you consume excess salt, you must absorb more water so that you can "flush"
out that salt. Remember from high school biology class, osmosis is the
movement of water from a region of low salt concentration to high salt
concentration. If you eat salt, then water follows that salt. Thus, it
follows that a steady diet of salty foods increases the blood volume, requiring
that the heart work harder. When you're hiking, the last thing in
the world you would want is to pump "diluted" blood, rather than pumping
the oxygen-rich blood your starving muscles demand. So the kidney works
harder to flush out the salt, the heart works harder to deliver oxygen
to the muscles, and YOU work harder because you have to transport and purify
all the water necessary to keep your body reasonably balanced. Would you
deliberately choose to carry extra weight along the trail? That's what
you are doing when you eat excess salt.
But don't I need more salt when I'm exercising?
Simply stated, "Salt in" should equal "salt out", i.e., you only need
to replace the salt that is lost. Most salt is lost through urine and perspiration.
Under normal conditions, the human body requires only 200 mg sodium ("salt"
= sodium chloride) to maintain balance. The Daily Reference Value (or more
familiar, RDA), based on a 2000 Calorie diet, is 2400 mg sodium, ten times
more than you "require", but enough to make your food taste good. At that,
most of us still eat twice the RDA/DRV in a day, so we consume more than
10 times what we need. Thus, even if you increased your perspiration
volume and urinary output tenfold on the trail, you would still be getting
enough sodium, given the typical American diet. (Depending on acclimitization,
approximately 1000 mg (1/2 teaspoon) sodium are lost in one quart
of perspiration. Therefore if your weight decreases by 6 pounds in the
course of a day of strenuous hiking, you have likely perspired off 3 quarts
--"A pint's a pound the world around". You could justify consuming an extra
3000 mg sodium that day.)
I really sweat a lot. Don't I need salt tablets?
Not if you are eating over the course of the day. Even food as "unsalty" as a fig bar contains 45 mg sodium. Do you snack on jerky, or trail mix with salted nuts? Do you dine on instant soups or prepackaged meals? Do you drink a sports drink such as Gatorade? A salt tablet contains 500 mg sodium, so a handful of trail mix or a helping of instant soup provides the equivalent of one or two salt tablets. (Compare values in Table 7.) As long as you are eating sufficient calories to sustain your exercise (approx. 3000-4000 Cal), it is not necessary to take a salt tablet. Salt tablets would only be necessary if you were sweating profusely (over 4 quarts/day) and drinking only water (not eating food or drinking other beverages). [Note: caffeinated beverages do not count as "drinks". Caffeine is a diuretic, so you lose almost as much fluid as you gain by drinking the beverage. Highly sugared beverages also "draw water" out of the body.]
With all that said, for any PCT hikers that are trailing across the Mojave desert or the Oregon lava beds in late spring or summer, you should be especially wary of salt depletion. You of all hikers will likely be losing quarts of sweat each day and you may not be consuming adequate food. Unless you are genetically predisposed to hypertension, go ahead and eat those high salt soups/pretzels! Dehydration due to excessive sweating and inadequate fluid intake can be life-threatening, but if you drink enough water so that what goes in comes out, you avoid the danger of dehydration.
What is the most reasonable way to reduce my salt intake?
If you are presently consuming over 4000 mg/day and you think your intake is excessive, here are some suggestions for moderating your salt intake.
1. Wean yourself gradually. Do you use salt in cooking and salt your food again at the table? Try eliminating one of these "exposures". (Removing the salt shaker from the table is the most effective, but meets with the most resistance with unconvinced consumers.) For example, fry eggs and potatoes without adding salt. Let each individual salt his/her portion at the table. Count shakes, and work from 6 down to 3 in the course of three weeks.
Cut the salt in half in your favorite recipes--you'll never miss it.
Same idea: Use 1/2 the spice packet with a package of Ramen noodles. To serve twice as many people, use three times as many noodles with the Macaroni & Cheese, adding sauted onions, mushrooms, and peppers for added flavor.
2. Select foods from the low salt column to balance out the foods you select from the high salt column. For instance, double the amount of water added to soup then add 1 cup additional vegetables. Vegetables are low salt. The soup then serves two, rather than one. Salt is cut in half. Or balance the high salt soup with a low salt cracker. With high salt processed/canned meats, eat low salt cereals/grains (like yeast breads or pasta) and vegetables.
3. Read labels! Compare brands. Buy reduced salt products. Many manufacturers are aware that there is a growing market for low salt alternatives. Note that natural cheeses are much lower in salt than processed cheeses. This is true for processed meats (bologna, sausage, pastrami, etc.), canned products and prepackaged meals. Eat all the dried fruits and vegetables you want. They are naturally low salt unless processed with added salt.
Table 7: SALT CONTENT OF TRAIL FOODS
Select the foods you are likely to eat when hiking.
= (>2 mg sodium/1 Calorie)
= (approx. 1 mg sodium/1 Calorie)
= (<1 mg sodium/2 Cal.)
|Instant oatmeal (270 mg)||Quick oats + dash of salt (<100 mg)||Quick oats, no salt (0 mg)|
|Gatorade (110 mg)||Hot cocoa mix (104 mg)||Orange/fruit juice (<25 mg)|
|American/processed cheese (406 mg)||Parmesan (93 mg/1 Tablespoon) No Added||Salt Swiss (12 mg)|
|Pretzels (486 mg)||Trail mix (seeds & fruit)(65 mg)||Unsalted pretzels (0 mg)|
|Instant pudding (410 mg)||Cookies/graham crackers (90 mg)||Fruit, fresh or dried (<5 mg)|
|Instant chicken noodle soup
|"Fantastic" instant soup (<300 mg/cup)||Vegetables, dried (<35 mg)|
|-----||Bread (125 mg)||----|
|5 Saltine crackers (180mg)||Uneeda unsalted carackers (100 mg)||Rice cakes (no salt added, 0 mg)|
|Kraft macaroni & cheese
(650 mg/3/4 cup)
|Macaroni (salted water) (<100 mg)||Pasta, rice (no salt in water, <5 mg)|
|Ramen noodles + spice packet
(465 mg/half serving)
|Ramen noodles + 1/2 spice packet
(260 mg/half serving)
|Ramen noodles (no spice packet)
(70 mg/half serving)
|Van Camp's chili beans (canned)
|Homemade chili beans (<200/ cup)||----|
|Tuna (Canned in water) (310 mg)||Powdered milk (125 mg)||----|
|Dry roasted peanuts (210mg)||Lightly salted dry roasted peanuts (90 mg)||----|
|Peanut butter (150 mg)||----||Sodium free p'nut butter (0 mg)|
Value in ( ) is mg sodium/serving. 1 teaspoon table salt = 2300 mg
sodium, the RDA
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