First off let me say that this is not a weight loss blog, this is about getting physically fit in case something happens in your life and you need to be physically able to act when your “fight or flight” response is activated. If you need to escape from immediate danger, then you need the ability to outrun that danger. If you need to “bug-out” from an area because it is too dangerous to remain there then you may need to travel, possibly on foot, a long distance before you arrive at a safer location. You need to be able to do that without injuring yourself, or your traveling companions. Your first instinct may be to load your pack on your shoulders and take off as quickly as possible, and that could be a real problem. Here’s why.

Your body uses two types of fuel for energy: glucose and fat. Your body makes glucose from the carbohydrates that you consume and is your body’s preferred energy source, but it does not store glucose very well and you only have about two hours worth of energy that you can access from glucose. Your body also uses fat, which it stores, and the average person has about 20 days worth of energy available from fat. There are also two types of activity – aerobic and anaerobic – meaning “with oxygen” or “without oxygen” respectively. If you are walking along and are not short of breath then you have all of the oxygen that you need, that is an aerobic activity. If you are walking briskly and you are huffing and puffing along and moving with great difficulty, that is anaerobic activity. When you are moving aerobically then you are burning more fat than glucose, and if your are moving anaerobically you are burning more glucose than fat. The better your physical conditioning the easier it is to move aerobically so you will use more of your fat stores for energy. In other words, the more fit you are the more fat you burn.

Now, I don’t want you to confuse the type of fuel you use with the volume of fuel – low level activity does not burn more fat than intense level activity. At lower levels of activity you burn proportionately less glucose, but you also burn proportionately less fat.

Now, those if us who are not physically fit (myself included!) use glucose for energy when we have to move quickly or if we have to do strenuous work, and not so much of our fat. I can’t tell you how many times I have walked the mile and a half to my gym as fast as I could, spent forty minutes vigorously lifting weights, then walked as fast as I could home. About halfway home I ran out of glucose. Athletes refer to that as “hitting the wall”. It’s bad. Really, it is.

Remember when I said that you body prefers to use glucose as fuel? Well your brain runs primarily on glucose. When glucose flow to the brain gets low you get mental fatigue, which causes muscle fatigue, and affects your mental preparedness. When you “hit the wall” you have a serious problem. Consuming carbohydrates when you are at that point really does not help – you body still has to convert it to glucose. Your activity stops. If you’re trying to bug out to a safer location and you “hit the wall” you’re done. If you don’t practice hiking with your bug out bag, it is likely that you won’t have the fitness level required to move a long distance without your body running out of gas.

Here is a second problem: heat. Whenever you move your body it generates heat. Apparently you use about 40% of your body’s fuel for activity and 60% of it to generate heat (see links below).

You can reduce the heat in your body by both putting liquid into it and sweating. As we all know, blood carries heat to your skins surface, making you sweat. When you sweat water through your skin that water evaporates and cools your skin surface, and that cool is carried back into your body by the bloodstream. But what if you are experiencing high humidity weather? You cannot sweat into water, your sweat will not evaporate. Also, the faster you go the hotter you get and the thicker your body is the harder it is to keep it cool. If you don’t have an adequate amount of blood (blood volume) then it cannot carry the heat out to your skin surface and the cool back in. To counter these conditions you would have to put more water into your body.

If you don’t have enough salt in your cells you also won’t have enough stored water. You body has to store it’s water/salt content at a specific salinity level. If you put in too much salt, then your body adds more water to the cells to dilute the salt levels, which can increase you blood volume and cause high blood pressure (hypertension) and that can be dangerous.

I have a problem in that I do not like salt on my skin when I sweat. It drips in my eyes and stings, so I haven’t been eating salty foods or adding salt to my meals. In my case there is not enough salt in my cells, so my body does not add water to my cells – the salinity levels have to be precise, remember? So I end up not having enough blood volume to carry the heat out to my skin or enough water to sweat out of my body. Shouldn’t I just drink more water when I have higher activity levels? Nope, won’t work.

There is a condition called hyponatremia, also known as low sodium in the blood. If you don’t have enough sodium then you get the following symptoms: confusion, headache, muscle cramping, nausea and vomiting, bloating of the abdomen and fingers, fluid in the lungs, seizures, coma. Fun, huh? Sounds kind of like heat stroke, doesn’t it? People would force more water into you if they saw you suffering from those symptoms. Guess who puts salt on their food now?

How do we fix these problems if we need to bug out? First of all, if you are in shape then you can metabolize fat, and I’ve already said that the best way to get into better shape is to start walking. If you can walk a mile without getting overly winded, then add a pack so you have added weight, and build up on distance. This will also build muscle, which metabolizes fat even when you are just sitting still.

Secondly, don’t “diet” and don’t skip meals. Studies show that overweight people actually consume fewer calories than normal weight people (see links below). What happens is that the fewer calories you consume the fewer you can consume – your body adjusts your metabolism to a lower rate and then when you go back to eating normal amounts again you gain weight. When you diet you compromise your metabolic mass (metabolic adaptation), so after your diet ends you have less muscle and more fat. Eating smaller more frequent meals maintains your metabolic rate, lowers your body fat and weight even if you are eating more calories and controls your blood sugar. Unless you have high blood pressure, you need to add salt to your meals. Eat better quality meals, eat them often, and eat proper portions.

Third, drink water on a fixed schedule, whether you think you need it or not. You also get water from foods such as fruit and vegetables, so you can “eat your water”.

Fourth, if you have to bug out I highly recommend that you add some sort of sports drink to your bug out bag. It will deliver liquid, salts, and carbohydrates to your body to help prevent overheating and “hitting the wall”.

Lastly, pace yourself in your activities. Be the tortoise!