Changes

* [[Maltodextrin| Maltodextrin]] is the most easily digested form of carbohydrate, 36% faster than glucose, making it ideal in a gel. More importantly, [[Maltodextrin ]] requires far less water to be isotonic than glucose or fructose[[Fructose]]. [[Maltodextrin ]] has little or no flavor, even at high concentrations. * Glucose is easily digested, but requires 6 times as much water as [[Maltodextrin ]] to be isotonic. Glucose is about three quarters as sweet as sugar (sucrose).

* A little bit of [[Fructose]] is useful, as fructose [[Fructose]] is absorbed via different pathways, increasing the total carbohydrate absorption above what is possible with [[Maltodextrin ]] alone. However, too much [[Fructose ]] will cause digestive problems and fructose [[Fructose]] is absorbed at about a forth the rate of glucose. It also requires the same amount of water as glucose to be isotonic. [[Fructose ]] is 1.7x as sweet as sugar (sucrose).* Sugar is a cheap ingredient and is half glucose and half fructose[[Fructose]].

| [[Fructose ]] malabsorption

* ^bAgave nectar varies in its fructose [[Fructose]] content between 90% and 55%, so this calculation assumes the average of about 75%.

* ^dThe sugar value includes sucrose, fructose[[Fructose]], glucose and other 'sugars'.* ^eThis is an approximation based on the amount of sugar, [[Maltodextrin]], sodium and potassium, ignoring other ingredients. The water included in the gel is assumed to be the overall weight less the weight of the carbs, fat and protein[[Protein]]. See [[The Science of Energy Gels]] for details on the isotonic calculations.

[http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=hammer&url=http%3A%2F%2Fwww.amazon.com%2FHammer-Single-Serve-Packets-Raspberry%2Fdp%2FB000RI2T4A Hammer Gel] is noteworthy as one of the easiest to digest gels. It is nearly all [[Maltodextrin]] dissolved in a greater volume of fluid than other gels. The low level of sugars and electrolytes makes this far easier on the digestive system, and is recommended for runners who have issues with other types of gel. Note the low level of [[Fructose]], which makes the maximum carbohydrate absorption lower than other gels. Therefore use Hammer only if Gu is difficult to digest. ''<br/>Ingredients (Vanilla): [[Maltodextrin]], Filtered Water, Energy Smart (Grape juice and Rice dextrins), Potassium Sorbate (as a preservative), Vanilla Extract, Citric Acid, Potassium Chloride, Salt, Amino Acids (L-Leucine, L-Alanine, L-Valine, L-Isoleucine).''

''</br>Ingredients (Apple Cinnamon): [[Maltodextrin]], Water, Apple Puree, Apple Concentrate, Citric Acid, Potassium Citrate, Sea Salt, Cinnamon, Potassium Sorbate and Sodium Benzoate.''

''<br/>Ingredients (Vanilla): [[Maltodextrin]], water, fructose[[Fructose]], Gu Amino acids (leucine, valine, histidine, isoleucine), potassium and sodium citrate, antioxidants (vitamin E and C),citric acid, calcium carbonate, vanilla, sea salt, preservatives (sodium benzoate, potassium sorbate), fumaric acid, herbal blend (chamomile, kola nut, ginger), pectin.''

The peanut butter flavored [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=gu&url=http%3A%2F%2Fwww.amazon.com%2FEnergy-Gel-Chocolate-Outrage-24-Count%2Fdp%2FB000CSCRHY Gu] is different enough to justify its own section. The peanut butter flavor is far less sweet than the regular Gu flavors, but if you like peanut butter it can be a lot more palatable. It also substitutes a little bit of fat and protein [[Protein]] for the carbohydrate, as well as having a tiny bit more sodium and potassium. I find this flavor digests particularly well and I'd recommend trying get if you're a fan of peanut butter. Obviously, if you hate peanut butter or you have a peanut allergy this is not going to work for you. The Peanut Butter flavor is one of the thickest gels, and is quite a bit thicker than the other flavors of Gu. Even in warm conditions it tends to be a little too thick, and in cold conditions it can become bit like a chewy candy such as taffy, toffee, etc.''<br/>Ingredients: [[Maltodextrin]], water, fructose[[Fructose]], Peanut butter (peanuts, salt), Gu Amino acids (leucine, valine, histidine, isoleucine), potassium and sodium citrate, antioxidants (vitamin E and C), preservatives (sodium benzoate, potassium sorbate), calcium carbonate, sea salt, fumaric acid, calcium chloride, pectin, citric acid, malic acid, herbal blend (chamomile, ginger).''

''<br/>Ingredients (Blueberry flavor): [[Maltodextrin]], water, fructose[[Fructose]], Roctane Amino acids (Histidine, Leucine, Valine, Isoleucine), Ornithine Alpha-ketoglutarate (OKG), sodium citrate, malic acid, citric acid, potassium citrate, natural pomegranate flavor, natural berry flavor, calcium carbonate, sea salt, caffeine[[Caffeine]], sodium benzoate, potassium sorbate.''

Vi Endurance has no fructose[[Fructose]], so it's ideal for those that suffer from [http://en.wikipedia.org/wiki/Fructose_malabsorption fructose malabsorption]. It has a little fat in the form of Medium Chain Triglycerides, as well as some Taurine, which I think are good things, but probably the amount is not significant enough to make much of a difference. There is a little caffeine[[Caffeine]], intended to increase the carbohydrate absorption rather than to improve performance. I found the Vi Endurance very easy on the stomach and a worthy alternative to Hammer Gel, though it's only from the manufacturer and so it a little more pricy ($1.64 with shipping.)''<br/>Ingredients (Vanilla): [[Maltodextrin]], water, dextrose, Vi Endurance Formula (MCT Oil, Taurine, Glucuronolactone, ornithine alpha-ketoglutarate (OKG), citrulline malate, magnesium [[Magnesium]] aspartate, sodium citrate, potassium aspartate), pure vanilla flavor, potassium sorbate, sea salt, caffeine[[Caffeine]]''

''<br/>Ingredients (Vanilla): Organic [[Maltodextrin]], Organic Sugar, Water, Natural Flavor, Sea Salt, Potassium Citrate.''

[http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=PBeg&url=http%3A%2F%2Fwww.amazon.com%2FPowerBar-Caffeinated-Strawberry-1-44-Ounce-Packets%2Fdp%2FB000A2BCIW PowerBar Gel] is noteworthy because of its higher sodium content that may help alleviate [[Hyponatremia]] and [[Cramps]]. I found the flavor stronger than Hammer, Gu or Cliff, but still quite pleasant. The level of fructose [[Fructose]] is higher than I'd like to see for digestibility. You may need to drink some water near the time you take PowerBar Gel due to the extra electrolytes. PowerBar Gel has a noticeably thinner consistency than most other gels, and is almost a liquid. This makes it far easier to take in cold weather as it does not go so thick, but it also make it trickier to mix with saliva in your mouth. ''<br/>Ingredients (vanilla): Carbohydrate blend ([[Maltodextrin]], fructose[[Fructose]]), water, electrolytes (sodium chloride, sodium citrate, potassium chloride), natural flavor, citric acid, sodium benzoate and potassium sorbate.''

The main ingredients in eGel are close to Gu, which is no bad thing. The main differences are that eGel is twice the size of Gu, does not come in caffeinated varieties and has more electrolytes. While eGel has more electrolytes per packet than PowerBar Gel, if you take into account then PowerBar Gel has the most concentrated electrolytes. The size of eGel may appeal to some people, but I generally find the usual size more convenient. The flavors of eGel are somewhat unusual in that they taste quite sour or 'tart', possibly because of the citric acid content. Flavor is a personal thing, so if you like sour, tart tastes, then you may get on well with eGel, but I found it overwhelming. However, it's possible that eGel may be acidic enough to help with [[cramping| Cramps]]. Another An oddity of eGel is that they contain coloring, which is strange given that most people will never actually see the gel. ''</br>Ingredients (Mountain Rush): [[Maltodextrin]], Filtered Water, [[Fructose]], Citric Acid, Sodium Citrate, Potassium Citrate, Natural Flavor, Amino Acid Blend (Leucine, Valine, Isoleucine, Histidine), Vitamin C (Ascorbic Acid), Vitamin E (Tocopherol acetate), Sodium Benzoate And Potassium Sorbate, Yellow 5, Vitamin B6''

I like the 4:1 carbohydrate to protein [[Protein]] ratio of [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=accel&url=http%3A%2F%2Fwww.amazon.com%2FPacific-Health-Accel-Vanilla-pack%2Fdp%2FB003CN5NL8 Accel Gel], and I often use it in ultramarathon races. There is more sugar than I would like at 13g and the thin consistency makes it harder to eat slowly and mix with saliva. ''<br/>Ingredients (Vanilla): Water, [[Fructose]], Sucrose, Whey [[Protein ]] Isolate and Hydrolysate, [[Maltodextrin]], Glycerin, Natural Flavors, Salt, Ascorbic Acid, Vitamin E Acetate, Soy Lecithin.''

The only ingredients in this [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=ch9&url=http%3A%2F%2Fwww.rei.com%2Fproduct%2F815338%2Fchocolate-9-energy-gel #9] are Agave and Cocoa, and Agave is predominantly fructose [[Fructose]] (55% fructose [[Fructose]] to 20% glucose). This amount of [[Fructose]] is slow to be absorbed and can be difficult to digest, making it a poor choice for most runners. The Agave makes this gel intensely sweet, which I did not like and the '[http://en.wikipedia.org/wiki/Dutch_process_chocolate processed with alkali]' means that most of the antioxidants are destroyed. This is also by far the thickest gel that I've tested so far, being more like a paste than a gel. This gel may be suitable for runners that suffer from a blood sugar drop after taking more conventional gels prior to exercise (see [[The Science of Energy Gels| The Science of Energy Gels]] for more details).

The ingredients in [http://go.fellrnr.com/?id=35454X937677&xs=1&xcust=SecondSurge&url=http%3A%2F%2Fwww.amazon.com%2FAccel-Gel-2nd-Surge-Expresso%2Fdp%2FB004Y96R6Y 2nd Surge] are rather grim, with Agave providing [[Fructose]] and Brown Rice Syrup providing glucose (as disaccharides and trisaccharides). While this may sound better than simply using all sugar, it's chemically not an improvement, especially as Brown Rice Syrup has a bitter aftertaste and unfortunately may contain [http://www.npr.org/blogs/thesalt/2012/02/23/147294466/in-rice-how-much-arsenic-is-too-much arsenic]. I found that 2^nd surge was overly sweet, with a slightly bitter undertones and rather gritty in texture. 2^nd Surge has a higher dose of [[Caffeine]] than most gels. It's unlikely that you'd want to take a 2^nd surge every 30 minutes, but if you did, you'd have 800mg of [[Caffeine ]] during a four hour marathon, which is rather high. (For a 150 pound/75Kg person, that would be nearly 11mg/Kg, far more than seems prudent.) The ratio of carbohydrate to protein [[Protein]] can have some benefits, but it's a 6:1 ratio, rather than 4:1 which the manufacturer claims is ideal in their Accel Gel. Overall, there seems nothing to recommend these gels. ''<br/>Ingredients (chocolate flavor): Agave syrup, brown rice syrup, evaporated cane sugar, water, whey protein [[Protein]] isolate, glycerin, pea protein [[Protein]] isolate, cocoa, natural flavors, green tea extract, d-alpha-tocopheryl, salt, grape, pomegranate, mangosteen, goji berry, blueberry, chokeberry, cranberry, apple and bilberry extracts.''

[http://go.fellrnr.com/?id=35454X937677&xs=1&url=http%3A%2F%2Fwww.rei.com%2Fproduct%2F837328%2Fvitalyte-chia-surge-energy-gel Chia surge] is one of the more unusual gels as it contains chia seeds which give it a bitty texture. I found that these seeds got caught in my teeth, even when I tried to swallow without chewing or mixing with saliva, which was amazingly annoying. Chia surge also has relatively few calories, too much glucose, not enough [[Maltodextrin ]] and almost no sodium. Chia Surge contains beta-Alanine which has been shown to improve sprint performance, though you'd likely need to take 4-12 packets a day for some days to see the benefit (see [[The Science of Energy Gels]] for more details). Overall it's hard to recommend Chia Surge. ''</br>Ingredients(Raspberry): Water, Dextrose, [[Maltodextrin]], Citric Acid, Fruit And Vegetable Juice (For Color), Natural Flavors, ULS (Organic Cane Sugar, Natural Flavors, Stevia).''

==Vespa Gel ==

[[Vespa Gels Gel| Vespa]] claims to improve endurance performance by improving fat burning rather than providing fuel like other gels. The science does not seem to back this up, and they are remarkably expensive ($6.75 each).

An alternative to energy gels is the solid blocks of carbohydrate, such as Clif Bloks, or Gu Chomps. I don't generally recommend these alternatives for a number of reasons. The biggest problem is that it's harder to chew a block than to swallow a gel while running, especially if you're breathing [[Breathing]] hard. A mistake can result in choking, which will really upset your running. The ingredients in the chewables are not as good as the gels – the primary ingredient in Clif Bloks is brown rice syrup and Gu Chomps use Tapioca Syrup. Sport Beans may be more convenient than the Clif Bloks or Gu Chomps but are nearly all sugar rather than the more easily digested [[Maltodextrin]].