WATER HYDRATION DEHYDRATION

WALKING WATERBAGS
Our blood is 90% water, our brain is 70% water, our bodies are 70% water. Basically we are walking waterbags. These levels of hydration are vital to our health and well being. Yet we lose a great deal of water as we pedal along the road. Everytime we exhale we lose moisture, since our expelled breath is always 100% saturated water vapor. We lose water through urination. Moisture evaporates from our skin continually in the form of insensible perspiration. And we can exude tremendous amounts through sweat.

THE EFFECTS OF DEHYDRATION
Water lubricates the joints in our hips, knees and ankles -in much the same way oil lubricates machinery. Dehydration reduces this lubricating effect, stiffening our joints and making them more susceptible to injury. Dehydration actually plays a key role in most sports related stress injuries. Moreover, as the body loses water, the blood thickens and decreases in volume, becoming more sluggish. This raises blood pressure and slows circulation. As such, it lowers the delivery rate of fuel and oxygene to the muscles. And it retards the extraction of the by-products of metabolism from the muscles. This makes us feel sluggish ourselves, sapped of energy. The dehydrating blood and restricted circulation also slows the brain's functions, impeding our mental processes and destabilizing our emotions. This can work to take the fun right out of the bike touring experience.

THE PSYCHOLOGY OF THIRST
The sensation of thirst is a poor indicator of when to drink water. By the time we feel thirsty we are already dehydrated. And while a few sips of cold water will usually satisfy thirst, such a small amount is not nearly enough to rehydrate the body. Not only does thirst come too late, but it shuts off too soon. Also, when our water bottles are empty, thirst can be a great tormentor, and the agony only worsens when we allow our minds to dwell on incessant thoughts of the cold drinks we do not have. All this is to suggest that thirst is mainly a psychological effect. It is a tool for helping us stay properly hydrated, but like any tool it has its limitations. So rather than rely on thirst to tell us when to drink water, we are better off tuning in to our body's physical signals.

SIGNS OF DEEPENING DEHYDRATION
The surest way to know how well hydrated we are is by remaining aware of our water consumption. For example, supoose that we have been cycling for five hours and have taken only a few small sips of water. Based on this information alone, we know that our body is dehydrated.

Let's look at some of the effects of dehydration, in their general order of occurrence.
1. After that half a days's cycling with only a minimum of water, we will notice (if we are paying attention) a marked decrease in urinary output. This is a signal that something is amiss, but unfortunately -as far as the body is concerned- it is a signal that is easily ignored. Nevertheless, this stage of dehydration is common among bikers.

2. The more hours spent cycling -without drinking enough water- the deeper dehydration. Higher altitudes and higher ambient temperatures accelerate the effect. As the day wears on, and as the urinary output continues to decrease in volume, it also begins to darken in color. Although dark yellow urine is pretty obvious, it is still easily disregarded. From here on, though, the body will start signaling in ways that are not so easily ignored.

3. Namely, the headache, which is often referred to -incorrectly- as "altitude headache or heat headache". Show me someone in the backcountry with a headache, and I will show you someone who is severely dehydrated. The dehydration may not be the only problem, but often it is. Unfortunately, most people fail to associate this signal with the dehydration. So rather than correct the problem by drinking lots of water, they take a few pain killing tablets. At least with this they drink some water.

4. Next comes the queasiness, most often the result of introducing pain killing medication into a severely dehydrated body.

5. And of course the constipation. Meaning that the digestive tract has slowed nearly to stop. When this happens, the person begins feeling seriously ill.

6. As the dehydrated biker continues disregarding these problems, his or her body becomes much more prone to stress injury. Initially this might be indicated by a budding pain, for example in the Achilles tendon, or in the back, or knee joints. All too often, though, the biker shrugs it off as "part of the ride", and takes more pain relief tablets which dulls the aches and pains but only masks the real problem. If the person carries on, and allows the dehydration to continue its spiraling descent, he or she may soon be courting a bona fide injury, perhaps in the knee or spinal disks -of course, calling it "accidental". The fact is, the severely dehydrated body is an "accident waiting to happen".

Any of these maladies make the trip less fun, and thoughts of returning home or giving up are more tempting. And any subsequent outings, with equally negative results, only reinforce the notion that cycling and camping are not very enjoyable. All for the lack of sufficient water intake.

RECOVERY FROM DEHYDRATION
Once deep dehydration sets in, it takes two or three days -not just minutes or hours- of drinking water voluminously to recover. So the best tactic is to consume generous amounts of water throughout the day. As a general rule, drink a quart of water during each hour's cycling, and much more in hot weather.

When cycling longer distances between water sources, do not let the extra weight of the water discourage you from carrying a decent supply. At the same time, it makes little sense to be a water hoarder -carrying it for purposes of security- or to simply ignore the need to stop and drink on a regular basis. Why arrive at a water source with a quart or more still in the bottles? at two pounds per quart, this is wasted effort. The best idea is to carry only enough to meet your needs, such that you arrive at the next source well hydrated, but with bottles empty. With a proper map or guide book in hand, this is generally not difficult to plan.

SURVIVAL TIME
How long can a person survive without water? According with contemporary medical knowledge, a person can walk without water in 90°F (35°C)temperatures for five days. At 60°F (18°C), survival is said to extend to eight days if the person is active, or ten if inactive.

So should you find yourself without water for a few hours or even a day or longer, this does not mean your life is at stake. Do everything within your power to remain well hydrated; and when that doesn't work due to unforeseen circumstances, strenghten your will, quiet your mind, and simply carry on -as usual- to the next water source.