1. Introduction

I think we all recognize that power (energy) gels are a convenient way to get extra needed calories, easily and quickly, into our bodies during endurance activities. There are alternatives, but sometimes you just don't have the energy or the stomach to eat solid food (especially at 3:00 am). I am sure we have all forced down dry power bars while hiking, trying to catch your breath between bites, trying to wash it down quickly with water, breathing heavily through your nose all the while. Power gels go down easier, are quick, do no take a lot of chewing and are easy on your stomach. But, they are not cheap. Also, a entire days supply of Power Gels results in a lot of garbage, sticky garbage, sometimes falling on the ground and littering or leaking in your pocket. Why not make your own in a convenient squeeze tube?



John Allred, PhD, food science communicator for the Institute of Food Technologists, simply shakes his head at the mention of energy products. "They are outrageously expensive for what you are getting," he says. "There's nothing magical about the ingredients."

Source:

2. Recipe

As explained in this article, I recommend using 75% brown rice syrup 25 % agave syrup (nector) or honey and 1 teaspoon of sea salt (or other natural, non refined salt or oral rehydration salts available from drug stores) per 300 grams. If you are using honey, I would recommend a ratio of 60% brown rice syrup and 40% honey due to the lower fructose conentration of honey (38% fructose, see section 8).



You can use barely malt syrup if available instead of brown rice syrup. You can buy barley malt syrup in bulk at most Beer Home Brew stores, as it is used to make beer. Maltodextrin can also be used to replace brown rice syrup and is typically easier on the stomach and not as sweet. It is available only as a powder and needs to be mixed with water to form a thin paste that can replace brown rice syrup.



Organic prefered for all ingredients. 1 tube = 300 grams.



This mixture of carbohydrates provides the glucose for immediate enegy, fructose for more gradually released energy and the complex carbohyrates for more sustained energy.



If you are a fan of caffeine, you can add some instant cofee, tea powder (green tea powder is recommended to also get antioxidants) or crushed up caffeine pills such as wake-up. Just be careful to not add too much, plus it may result in a bitter taste.



If you prefer to flavor your home made gel, you can add whatever flavor your like. I recommend natural flavoring if at all possilbe. You can buy natural extracts that can be added, such as Vanilla, chocolate, pepermint, ect. I personally like the flavor of the plain gel and can't be bothered to add anything else.



To get all the ingredients to blend, place the tube (see section 10) in hot water to help reduce the viscosity, then you can rotate the tube to mix (let the air bubble rise and blend). If you are adding caffeine, you are probably best to make sure the mixture is blended before putting in the tube, heating and stirring as necessary. Probably more of a hassle than it is worth.

3. Glycemic Index (GI)

If our only goal was to consume carbohydrates, then our cheapest option would be to consume cheap corn syrup or sugar syrup (sucrose). However, it is important to consider how quickly the sugar will be digested and delivers its energy. The glycemic index is often used by diabetics to control blood sugar levels; it is very useful to determine how quickly foods get converted to energy. The higher the glycemic index a food has, the quicker the sugar hits your blood stream and gets converted to energy. High glycemic sugars often result in an energy low after the initial rush. When all the sugar enters your blood stream, you body releases insulin to lower your blood sugar level. High sugar spikes result in excessive releases of insulin which then results in over compensation and then excessive lowering of blood sugar. Spikes are hard to control, it is better to provide a steady stream of sugars thereby preventing highs and lows (mountains and valleys). The key to sustained energy is selecting the proper carbohydrate.



The following lists the glycemic index of sugars. Note that the reference is white bread which is 100 (sometimes glucose is used as a reference and is pegged at 100).





Fructose =32

Agave Nectar =38

(note, corrected value from 27)

Lactose =65

Honey =83

High fructose corn syrup =89

Sucrose =92

Glucose =137

Glucose tablets =146

Maltodextrin =150

Maltose =150

Brown Rice Syrup (info. not available)

4. Sugars

4.1. Monosaccharides

Three common sugars share the same molecular formula: C6H12O6. Because of their six carbon atoms, each is a hexose.

glucose - "blood sugar", the immediate source of energy for cellular respiration

galactose - a sugar in milk (and yogurt), and

fructose - a sugar found in honey. Fructose is the sweetest naturally occurring sugar, estimated to be twice as sweet as sucrose.





Although all three share the same molecular formula (C6H12O6), the arrangement of atoms differs in each case. Substances such as these three, which have identical molecular formulas but different structural formulas, are known as structural isomers.

Glucose, galactose, and fructose are "single" sugars or monosaccharides. Two monosaccharides can be linked together to form a "double" sugar or disaccharide.



4.2. Disaccharides

Three common disaccharides:

sucrose — common table sugar = glucose + fructose

lactose — major sugar in milk = glucose + galactose

maltose — product of starch digestion = glucose + glucose. Maltose can be broken down into two glucose molecules by hydrolysis. In living organisms, the enzyme maltase can achieve this very rapidly





Although the process of linking the two monomers is rather complex, the end result in each case is the loss of a hydrogen atom (H) from one of the monosaccharides and a hydroxyl group (OH) from the other. The resulting linkage between the sugars is called a glycosidic bond. All sugars are very soluble in water because of their many hydroxyl groups. Although not as concentrated a fuel as fats, sugars are the most important source of energy for many cells.

Carbohydrates provide the bulk of the calories (4 kcal/gram) in most diets, and starches provide the bulk of that. Starches are polysaccharides.

5. What are the best Sources of Carbs?

If we wanted the lowest glycemic index for our power gel carbohydrate we would probably use Agave Syrup or complex carbohydrates. Agave is actually suitable for diabetics because of such a low GI and the slow rate it raises blood sugar. However, during endurance activities we want not only sustained energy but an immediate boost as well. An immediate boost that is then sustained by lower GI carbs. Power Bar has done some research, whether or not it is biased is unknown to me, but they determined that a ratio of 2:1 glucose to fructose resulted in an increase of 20 - 55% carb oxidation rates (burning fuel faster = more energy). See the excerpt from their studies below.



Source: By feeding a blend of glucose and fructose, investigators repeatedly found that maximum carbohydrate oxidation rates were raised by anywhere from 20% to 55%. When glucose was supplied in the form of maltodextrin, the same boost in the rate of carb burning was seen. Maltodextrin, also called glucose polymer, consists of units of glucose connected together, so it effectively delivers carbs and has the added benefit of tasting less sweet. Upon ingestion, the glucose chains are easily split apart to yield individual units of glucose. So, for purposes of boosting carbohydrate oxidation rates, studies show that either maltodextrin (or maltose) or glucose can be combined with fructose.



Cliff uses Organic Brown Rice Syrup for their source of carbohydrate in their gel. Brown rice syrup is roughly 50% soluble complex carbohydrates, 45% maltose, and 3% glucose. As explained above in section 3, maltose can be broken down into glucose in our bodies fairly quickly (and therefore has the same GI). The 50% of maltose/glucose of brown rice syrup provides the inital energy needed during endurance sports, and the complex carbohydrates provide the sustained energy. If you agree with powerbar's reserach, then this mixture would benifit greatly by adding some fructose to get the 2:1 ratio of glucose to fructose. Therefore since 50% of brown rice syrup is basically glucose (maltose breaks down immedaitely into glucose), we would need to add 25% total volume of fructose for this optimum blend. Therefore, I figure that the best carbohydrate mix is 75% brown rice syrup and 25% agave syrup or honey (both rich sources of fructose). If you are using honey, I would recommend a ratio of 60% brown rice syrup and 40% honey due to the lower fructose conentration of honey (38% fructose, see section 7). This mixture provides the glucose for immdiate enegy, fructose for more gradually released energy and the complex carbohyrates for more sustained energy. Barley malt can be substituted for brown rice syrup as it is basically the same mixture of maltose and complex carbohydrates (a little more % of maltose). Another option that I havenot tried is to use maltodextrin. It is typically purchased as a powder buy can be mixed with water to form a gel or thin paste that can be used in place of brown rice syrup. I plan on purchasing some and trying it out to see how well it can be used as a gel and will update this article. One of the main benefits of maltodextrin is that is it easily digestible and not likely to cause stomach upset. It is also not as sweet as the other options.

6. Commercially Available Energy Gels

6.1. Power Bar Energy Gel



Ingredients: Maltodextrin, Filtered Water, Fructose, PowerBar® Electrolyte Blend (Sodium Chloride, Sodium Citrate, Potassium Chloride), Citric Acid, Sodium Benzoate and Potassium Sorbate (to retard spoilage), Natural Flavor.



Nutritional Facts: Serving size = 41 grams = 1 packet.

110 Calories, 0 from fat.



Total Carbs = 27 g (9% of DV), sugars = 10 g, 200 mg Sodium (8% of daily value) and 20mg Potassium (1% of DV)



Price = $1.25 per packet = $3.05 / 100 grams



6.2. Cliff Shot Energy Gel



Ingredients: Organic Brown Rice Syrup, Sea Salt, Natural Flavors, Potassium Citrate, Magnesium Oxide



Nutritional Facts: Serving size = 32 grams = 1 packet.

100 Calories, 0 from fat.



Total Carbs = 25 g (8% of DV), sugars = 8 g, 40 mg Sodium (2% of daily value), 30mg Potassium (1% of DV)



Price $1.00 per packet = $3.125 per 100 grams



6.3. CARB-BOOM



Plain Vanilla

Ingredients: Maltodextrin, Water, Fructose, Natural Flavors, Sodium Acid Sulfate (acidulant), Potassium Citrate, Sea Salt, Citric Acid, Potassium Sorbate and Sodium Benzoate (to retard spoilage).



Nutritional Facts: Serving size = 30 grams? (not given) = 1 packet.

110 Calories, 0 from fat.



Total Carbs = 27 g (9% of DV), sugars = 3 g, 50 mg Sodium (2% of daily value) and 50mg Potassium (1% of DV)



Price $1.50 per packet = $5.00 per 100 grams (OUCH)



The ABC's of Energy Gels: A Full-Flavored Way to Sustain Energy

7. Electrolytes

We have all heard the importance of electrolytes in our gels and fluids during endurcae activites. In oral rehydration therapy, electrolyte drinks containing sodium and potassium salts are used to replenish the body's water and electrolyte levels after dehydration caused by exercise, diaphoresis, diarrhea, vomiting or starvation. Giving pure water to such a person is not the best way to restore fluid levels, because it dilutes the salts inside the body's cells and interferes with their chemical functions. This can lead to water intoxication.



Therefore, in order too add electolytes to our home made gel, add a teaspoon of sea salt per or natural salt that contains a mixtures of salts (inculuding some potasium salts) per tube of gel (300 grams of gel).



You may also choose to add oral rehydration salts that are available at drug stores to prevent and treat dehydration. These are available in a powdered form that can be added as per the instruction. They usually include some sugars and various salts. One such brand is gastrolyte.

8. Sources of Sugars

8.1. Brown rice syrup

Source: Brown rice syrup is a sweetener derived by culturing rice with enzymes to break down the starches, then straining off the liquid and cooking it until the desired consistency is reached. The final product is roughly 50% soluble complex carbohydrates, 45% maltose, and 3% glucose. The glucose is absorbed into the bloodstream immediately, the maltose takes up to one and a half hours to be digested, and the complex carbohydrates take from two to three hours, providing a steady supply of energy. Rice syrup has a shelf life of about a year, and once opened, should be stored in a cool, dry place. Brown rice syrup is considered to be one of the healthiest sweeteners in the natural food industry, since it is produced from a whole food source and is made up of the simple sugars.



8.2. Agave Nectar

A sweet syrup, like honey, but a little thinner in consistency. Because it has a low glycermic index and will not elevate blood sugar, it is a great honey replacement for diabetics and low-glycemic dieters. Premium Dark Agave contains 85% fructose made with 100% Agave tequilana weber azul. A mineral rich, dark syrup with a vanilla-like aroma.

Agave nectar is made from the juice of Agave Tequilana, the same variety of agave that is processed into the alcoholic drink tequila. The agave plant is considered the "Mexican Tree of Life and Abundance" and was a favorite food of the Aztecs. Enzymes are added to turn the complex sugars of its nectar into a simple sugar syrup.



8.3. Barley malt

Barley malt is a thick, dark, slow-digesting sweetener made from sprouted barley. It has a malt-like flavor. Some say barley malt is to beer as grapes are to wine. It is ideally suited to brewing for many reasons: Malted barley has a high complement of enzymes for converting its starch supply into simple sugars; it also contains protein, which is needed for yeast nutrition. Another important element is its flavor. Pure malt extract, which is relatively expensive, is sometimes adulterated with corn syrup, which is cheap. Barley malt extract (available in powder and liquid forms) is also used medicinally as a bulking agent to promote bowel regularity. Barley malt syrup metabolizes slowly in the body but does have calories and carbohydrates. Diabetics and low-carb dieters should use it with caution. Otherwise, it is fine for anyone who wants a whole-food natural sweetener. Barley malt syrup is considered to be one of the healthiest sweeteners in the natural food industry, since it is produced from a whole food source and is made up of the simple sugars.



8.4. Honey

Honey is a mixture of sugars and other compounds. The specific composition of any batch of honey will depend largely on the mix of flowers consumed by the bees that produced the honey. Honey has a density of about 1500 kg/m3 (50% denser than water), which means about 12.5 pounds per US gallon.



Typical honey analysis

Fructose: 38%

Glucose: 31%

Sucrose: 1%

Water: 17%

Other sugars: 9% (maltose, melezitose)

Ash: 0.17%





8.5. Maltodextrin

Another alternative to brown rice syrup is maltodextrin. They are easily digestible carbohydrates made from natural corn starch and are less likely to cause stomach upset. The starch is cooked, and then acid and/or enzymes are used to break the starch into smaller polymers (a process similar to that used by the body to digest carbohydrate). Maltodextrins are generally sold as dried powders and are polymers of dextrose (sometimes labeled "glucose polymers"). Their glycemic index should be considered metabolically equivalent to glucose (dextrose). Maltodextrin is readily available online for approximately $4/lb plus shipping. One source is http://www.nutritiongeeks.com/carbo-gain-maltodextrin-now-7/carbo-gain-maltodextrin-now.html

9. Price Comparison

As seen above, the price of powergel and cliff gel is $3.13/100 grams. You can buy brown rice syrup online for approximately $3.75 for 16 ounces. I bought 596 grams worth at a health food store for about the same price. For some reason some measurements are in weight and some in volume. I estimate 30 ml = 42 grams. Using the weight comparison and the price of $3.75 / 596 grams = this equates to $0.63/100 grams, or 1/5th the price of the commercially available powergel. For the added fructose, you can buy honey cheaper than brown rice syrup and agave syrup runs about the same cost, maybe a little more depending on where you live (it is not as available as brown rice syrup). You can buy brown rice syrup and agave syrup for less online or in bulk if you can find it, and the savings will be even better (depending of shipping rates). Use www.froogle.com to find the best deals online.

10. Packaging



I like using the following Coghlan squeeze tubes to package my home made power gel. One tubes holds a full day worth of gel, approximately 300 grams or 10 servings of the Cliff gel. I simply pour the syrup in the correct ratios (see section 2) into the open end of the tube, add a teaspoon of salt and fold the end over and insert the clip. Do not fill the tube more than 2/3 full or else you will end up with a sticky mess.



Coghlan's Squeeze Tubes - Package of 2 for $3.35

These reusable squeeze tubes are perfect for packing along food and condiments for camping, hiking or climbing. Open end allows easy filling; then simply fold and clip to keep food in the tubes. Remove the clip and wash the tube for convenient reuse.



You can also order Gel Flasks from www.carbboom.com for $3.00 each. Here is what they say on the website:

This flask holds 5 packets of Carb-BOOM energy gels. Use the flask to dispense as much or as little as you need. Store unused portions in the refrigerator for your next workout or race.