Your Body Will Be Under a Tremendous Amount of Stress
There are several things that happen under stressful conditions from a physiological perspective. As explained in earlier articles, your body burns off stores of glycogen (stored in the muscles) until it runs out. Without replenishment, the body cannibalizes its muscle tissue and “manufactures” its glucose and glycogen requirements. After “hitting the wall” (your body’s limit, usually reached within an hour or so), you burn off muscle tissue during this cannibalistic phase at a rate of 5 grams of muscle protein for every thirty minutes of prolonged effort.
With epinephrine and norepinephrine going haywire during your “fight or flight” metabolic reactions  and with adrenaline pumping levels to the moon, your body will consume a tremendous amount of energy. When there is any kind of a lag, the body kind of “sags” as it attempts to relax. Notice how I wrote “attempts” here? So, how do we solve this one?
Some kind of snack  would be beneficial, and keeping in mind what we wrote earlier, you may not have the time for it. Remember what I wrote for you a few articles back:
You need to ingest protein  and carbohydrates within 20-30 minutes of a strenuous workout, and more if the workout is protracted.
That being mentioned, many people turn to things such as power bars to make up for the protein and carbs. Those are OK, but make sure you have plenty of water when you eat them, or else they’ll pull water right out of your cells in order for your body to digest them…leading to dehydration .
If You’re Bugging Out, Make Sure You Have These Energy Enhancers
Even then, you may still be “lagging” for a while waiting for your body to extract what it needs. In the meantime, try the caffeine. Instant coffee can be consumed in an instant, just as the name implies.
While in the service, our MRE’s came with packets of coffee  (Taster’s Choice, to be exact). We “stocked” up on them and kept those packets handy for when we might need them besides just (if we could do it) the proverbial “morning cup of Joe.” Be careful not to take in too much…but if you’re in a bind and don’t have a lot of time to restore your mental alertness, the caffeine in a helping of instant coffee (either in a happy manufactured packet or one you make up yourself) can do you some good. I’m going to cite the PDR for Herbal Medicines, page 215, for Coffee for you:
“Quantities corresponding to as much as 500 mg of caffeine daily (5 cups of coffee) spread out over the day are toxicologically harmless for healthy adults accustomed to drinking coffee.”
The PDR goes on to state that dosages of 1,500 mg per day can lead to problems, but unless there are underlying health concerns such as arrhythmias, there is normally no real concern. Consult with your friendly and happy family physician before using the coffee.
Many people extol the virtues of guarana , and if it works for you, that’s great. Understand that guarana seeds (from which the energy drinks are made) main constituent to provide that energy is none other than caffeine, as well as theobromine and theophylline, two purines that are also stimulants. Guarana is listed as a tonic for fatigue in the PDR. Caffeine  overall is also an appetite suppressant.
Keep this in mind: caffeine is also a diuretic, meaning that it works against ADH (anti-diuretic hormone) and increases the frequency of your urinations. Care must be taken when using it so as to prevent dehydration. Ensure you take in enough water to prevent it from occurring.
Please let me clarify one final time with all of this: I’m referring to a situation that you’re not going to get any real rest for a long period of time. All of these items in the form of premade beverages, dried product, or tablets can be purchased in advance and stocked aside for the time you may need to rely on them. Let’s hope that need never arises and still plan for it nonetheless. Keep in that good fight, drink some coffee (just because it’s good!) and take care of one another! JJ out!