Part 3 - Nutrition & Physiology

In the summer if you are out-of-shape, or you have poor nutrition, or become dehydrated, you can finish the hike. Maybe under some distress or pain. But, in winter mistakes can cost you your life. Here are some tips and rules that you should be aware of:

Potassium is absolutely essential to keep your muscles from cramping. Potassium is required for muscles to work. A shortage of the mineral will cause muscle cramping. Many people know that you can get potassium from bananas, yogurt, potatos, and other food sources. Many people believe that if they eat a banana or extra yogurt the day before this will be enough for the hike. Unfortunately, it doesn't work that way. To increase your potassium level requires several days of potassium loading to have enough for a hike. It is important to increase your level of potassium a week before your hike with potassium rich food.

Potassium is a mineral where it can be too dangerous to have too much potassium and dangerous to have too little potassium. Too little or too much can lead to sudden death. The best way to help your body is to adjust your diet so that you some of the food you eat has more potassium.

Your body needs both sodium and potassium. Many years ago it was possible to have too little sodium, and this would also cause muscle cramps. But, today most people consume some type of processed foods. Most processed foods have far more sodium (salt) then the body needs. Today, sodium deficiency is unheard of . Some people believe that if they have muscle cramps, they are sodium deficient. Nothing could be further from the truth. One problem is that both sodium and potassium compete with each other. Having too much salt can actually cause more problems. A large percentage of the population has 300% more sodium then is required. So, it is important to reduce your sodium intake, and increase your potassium intake through potassium rich foods.

Many experienced hikers will consume a yogurt and banana a day to increase their potassium level. Each person needs to evaluate their diets to determine what changes they need to do. If you are uncertain and continue to have problems, then it would be wise to consult a nutritionist.

Water Is the most important food source for your body. Most people can survive for 3 weeks without food. But, few people can survive 3 days without water. It is the most essential element you can provide your body. It is important that you continue an steady intake of water. While you need more water in the summer, you still need to bring water on your winter hikes.

One of the biggest problems with carrying water in the Winter is that it will freeze if not properly cared for. Some water bladders will freeze up. Some only freeze up near the mouth piece. Some hikers keep the tube and mouth piece inside their jacket so that it will not freeze. Other people bring bottled water. If you bring bottled water, you need to keep it in your pack next to your body to keep it from freezing.

When hikers run out of water during a Winter hike, it creates problems. Often times, the streams are frozen. You are surrounded by water, but viable water becomes difficult. If you eat snow, it will require a lot of energy and heat from your body to warm it up. Some experienced hikers bring along a small alcohol stove to melt and warm up water in a pop. This is the best way to obtain water in the backcountry.

As you use your muscles, they build up lactic acid. You need to be hydrated to remove the lactic acid from your muscles. If you are dehydrated, then you will start to get muscle cramps from lactic acid buildup. So, it is very important to stay hydrated. You can also use over the counter pain relievers to help reduce this problem. After your hike you should always try to get fully hydrated as soon as possible to prevent muscle cramps later in the evening.
So, to review how to reduce or eliminate muscle cramps you need to do five things: (1) Change your diet so that you increase your potassium levels and reduce your sodium levels; (2) Condition your muscles so that they use less energy and produce less lactic acid; (3) Hydrate during AND after the hike so that your urine is a pale yellow; (4) Take pain killers, like Advil or Aleve, after your hike (if needed). (5) After your hike, move around some to prevent the build up of lactic acid in certain parts of your muscle.

Heat Regulation Your body has a very complex method of heat regulation. Your body has the ability to divert blood flow in complex ways depending up excess heat, hypothermia, or injury. Furthermore, some people have a problem with cold hands and feet, while other people have hot hands and feet. On the same hike, one person may be hiking without gloves, while the other person is hiking with thick mittens and heat packs. Some people have a problem of getting too hot during a hike, and then get too cold if they stop. It is important to understand how your particular body reacts to exercise and weather extremes. During Winter hiking it is important to properly regulate your body's heat.

Without getting into the complex biochemical and physiology I can tell you that your body heat is regulated by hormones. The hormones controls the expansion and constriction of blood vessels. Additionally, if the body becomes too hot your body will allow the skin to excrete water and salt to increase evaporation to help cool the body. If the body becomes too cool, the body is complex enough to constrict blood vessels in the arms and legs to maintain the core body temperature in the torso and head. If the torso cools off too much, the heart will stop. Additionally, as the head cools, the your ability to make wise decision declines rapidly. It is like becoming drunk without even knowing it. Listed below how your body will respond to different ranges of temperatures:

Body Temperature Description

109-115 F Brain Damage, Shock, Convulsion, Cardio-respiratory failure and Death

106-109 F Fainting, head-ache, dizziness, confusion, hallucinations, delirium, drowsiness, convulsion, and shock

100-104 F Sweating, Red-faced, weakness, vomiting, headache and dizzines

98-99 F Normal Temperature Range

93-97 F Shivering, numbness and bluish-gray skin, difficult moving fingers, confusion

88-91 F Confusion, sleepiness, slow reflexes, heart beat, and breathing, hallucinations, delirium, comatose, unconscious

75-88 F No movement, irregular heart beat, respiratory arrest, and death

It should be noted that people who go into cardiac arrest from hypothermia can be revived up to an hour after going into cardiac arrest instead of the typical four minutes at 70F. Anna Bågenholm who is a radiologist in Sweden was skiing with friends, when she fell through a stream bed. She fell upside down into the stream and suffered hypothermia. After 40 minutes she went into cardiac arrest. CPR was started 80 minutes after she fell in. Her body temperature fell to 57 degrees. It took doctors 9 hours to get a heart beat back. They had placed her on a cardiopulmonary bypass machine to warm up her blood. She was in the ICU for 10 days, and 2 months of rehabilitation. She still has some minor nerve damage. She represents the most amazing recovery of a hypothermia patient. Her medical case changed the way doctors treat other heart failures and hypothermia.

For Winter hiking you MUST be very aware of your body temperature. And, you must regulate it by putting on or taking off clothing to maintain a steady temperature. This is why it is important to wear layers of clothing. Most people do not think about it until your body temperature reaches extreme levels. During winter hiking, you cannot wait that long. You must think about your body temperature constantly, and regulate it by adding or taking off clothing. Doing this will also conserve your water level and require the least amount of water intake. It can be 20 degrees out, and you may be hiking in a light polyester shirt and no gloves to keep yourself from sweating.

The biggest question is what is a steady temperature? The best temperature level for hiking is where you feel slightly cold. But, not too cold where your temperature level in your arms and legs start cooling off. And, not too hot where you start to sweat. You don't want to be comfortable. You want to feel slightly cold. You can regulate your temperature by adding or subtracting clothing, AND increasing or decreasing your speed. This is why it is important to keep your hiking group small. Four or five people at the maximum.

The three primary conditions for hypothermia are: (1) Air temperature; (2) Wind; (3) Getting wet. Air temperature is fairly predictable. A good weather report will give you a fairly good idea of what the temperature will be. The wild card is when you spend an unexpected night in the woods. Temperature drops at night can be 30 degrees colder then during the day. Furthermore, without sunlight, it will feel even colder. Remember it is always colder on the summits of mountains then in the valley. Wind can always cause you to feel much colder. The solution is to wear wind-resistant clothing on windy days. Summits can also be quite windy. You should always bring a shell jacket to protect you against the wind. Certain mountains in the Catskills can get hurricane force winds. Those mountains are on the eastern side of the Catskill Mountains. You should always beware of a possible wind event while hiking on the eastern escarpment. Getting wet is always significant. If you fall into cold water in the Winter you can die of hypothermia within 10-15 minutes. Falling into a stream can remove heat from your body 3,000% faster then exposing your skin to air. If you encounter an event where all three conditions occur at the same time, you may have a significant problem with surviving. Seth Lyon encountered all three conditions during his trip to the Blackhead Mountains in March of 2010. He had temperatures in the 20's along with hurricane force winds and the hard blowing snow made his clothing wet.

If you encounter conditions where your body produced less heat then the heat your lose, then you will become hypothermic. Hypothermia is when your body becomes too cold. Physiologically, you body will constrict all blood vessels to your arms and legs to try and keep your body temperature regulated at the normal temperature range for your brain and torso. When your brain starts to drop in temperature, you will feel like you can think clearly. But, in reality you will think like you are drunk. A short time before Seth Lyon died of hypothermia, he knew that he had to get out of his snow pit, and get help. After he climbed out of the snow pit, he tried to put on his snowshoes. But, being too cold he couldn't get the bindings tighten up. He then proceeded to walk off without his snowshoes on. This is the kind of mistake that someone with hypothermia does. In 8' of snow, he didn't get very far. He died a short time later. This is one of the reasons why you should never split your group up. A group thinks better then a smaller group or individual. Sometimes when people become hypothermic, they will become so deluded that they will take some of their cloths off. As their torso cools off, their heart will eventually stop beating due to a drop in temperature of their heart and blood.


	How the body responses to Hypotherma

Hypothermia is always a concern for winter hikers. But, hyperthermia can also be just as dangerous. Hyperthermia is when your body becomes too hot. Your body regulates too much heat by expanding the blood vessels in your body to allow heat to escape through your hands, arms, and feet. Additionally, your body will excrete water (sweat) to allow cooling of the body. Just like getting wet in a stream. The winder it is, the faster you will cool off from sweating. Most experienced hikers do not like to allow themselves to sweat. Once the hiker sweats, their clothing then must get rid of the sweat to keep from getting too cold.

It is a myth that your head plays a major role in allowing your body to keep or expend heat. People wear a hat to keep their brain warm. You don't wear a hat to keep your body warm. You wear a hat to help keep your brain from getting cold. But, in reality, your brain gets most of it's heat from your blood stream. But, using a wind-proof hat can be very helpful. Your hands are the most important part of your body in removing heat from your body. Listed below is a table showing which parts of your body allow the most amount of heat to escape when your body overheats:

Body Part Surface Area in Meter Sq Ideal Temperature C Heat Loss at Ideal Temp (Kcal/m sq * hr)

Hands 0.07 28.6 228.6

Forearms 0.08 30.8 107.5

Arms 0.10 33.0 84.0

Feet 0.12 28.6 83.3

Calves 0.20 30.8 73.0

Thighs 0.33 33.0 36.0

Buttocks 0.18 34.6 46.2

Back 0.23 34.6 53.9

Abdomen 0.12 34.6 37.5

Chest 0.17 34.6 48.3

Head 0.20 34.6 20.0

It is also important to understand which organs produce the most amount of energy at REST. Your heart produces 45 cal/100g-minute. Your kidneys produces 35 cal/100g-minute. Your brain and torso produces 15 ca/100g-minute. Your muscles and and skin produces 7 cal/100g-minute. Your hands and feet produce 0.5 cal/100-minute. When your body is exercising, then the muscles consume very large amounts of energy and heat. The heart will consume 400% more energy under heavy exercise. But, your body's muscles will consume vast amounts of energy and heat.


	Areas of the body that consume the most amount of energy

Your skin and muscles produce 18% of the heat when the body is at rest. But, when hiking it produces up to 73% of the heat.
Your torso produces 56% of the heat when the body is at rest.
But, when hiking your torso produces 22% of the heat. During exercise, the capillaries will open up to allow heat to escape. The change in surface area is massive. It is estimated that open capillaries will create 3000-6000 square feet of surface area to allow heat to escape. More surface area then most houses! Listed below is a chart showing the amount of blood flow at different exercise levels. When hiking your skeletal/muscles will produce massive amounts of heat.

Body Part Blood Flow (ml/min) at REST Blood Flow (ml/min) at Light Exercise Blood Flow (ml/min) at Heavy Exercise

Splanchnic 1,400 1,100 300

Renal 1,100 1,100 900

Brain 750 750 750

Coronary 250 350 1,000

Skeletal/Muscle 1,200 4,500 22,000

Skin 500 1,500 600

Other 600 400 100

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