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==Digestive Path==
While fructose has a low isotonic concentration and a low glycemic index, it can be absorbed via a different path ([http://en.wikipedia.org/wiki/GLUT5 GLUT5]) to glucose and Maltodextrin ([http://en.wikipedia.org/wiki/GLUT2 GLUT2]). This means that if you have enough glucose or Maltodextrin to saturate that absorption path, adding fructose will improve the overall usage of the carbohydrate intake<ref name="Rowlands-2008"/>.
==Optimal Carbohydrate Intake==
Most studies have shown that glucose and Maltodextrin can be absorbed and metabolized at up to 1.0 grams/minute, while Fructose is absorbed and metabolized at up to 0.6 grams/minute<ref name="Jeukendrup2004"/>. Combining Fructose with glucose/Maltodextrin can result in the metabolism of up to 1.75 grams/minute<ref name="Jeukendrup2010"/>.
=Ingredient Analysis=
Here is an analysis of the most common ingredients
* '''Amino acids''' may help performance, but the evidence is unclear at the levels provided in most gels.
* '''[[Caffeine]] '''is great for improving performance and speeding the absorption of carbohydrate.
* '''beta-Alanine''' is an amino acid contained in Chia Surge. Most studies have shown that beta-Alanine will improve sprint performance<ref name="Hoffman-2008"/><ref name="Artioli-2010"/><ref name="Baguet-2010"/><ref name="Van Thienen-2009"/><ref name="Derave-2007"/>, with only one showing no benefit<ref name="Sweeney-2010"/>. Note that most studies used 2-6g/day of beta-Alanine, which is 4-12 packets of Chia Surge per day. Beta-Alanine may cause a harmless tingling of the skin<ref name="Artioli-2010"/>.
=Reactive Hypoglycemia =
In some people their blood sugar will drop to lower than normal levels after a high carbohydrate meal, a condition known as Reactive Hypoglycemia<ref name="Brun"/>. This condition effects some athletes who take carbohydrate before exercise<ref name="Kuipers-1999"/>, but not if the carbohydrate is taken during the warm up<ref name="Brouns-1989"/> or immediately before exercise<ref name="Jeukendrup-2010"/>. It appears this hypoglycemia is specific to some individuals<ref name="Moseley-2003"/>. However, there appears to be no performance impact from this hypoglycemia<ref name="Jeukendrup-2010"/> and I found no reports of hypoglycemia in response to carbohydrate taken during exercise.
=Viscosity=
[[File:Gel Viscosity.JPG|right|thumb|200px|The funnel and measure used to test the viscosity of gels.]]
For the [[Comparison of Energy Gels]] the viscosity of gels was simplistically measured by measuring the time it takes for 5ml to flow through a funnel. The temperature for all tests was approximately 68f/20c.
=Isotonic Calculations=
For those interested, there is the math behind the isotonic calculations I use on my [[Comparison of Energy Gels| Comparison of Energy Gels]].
** Therefore potassium chloride would require ~89 ml/g (500/5.6) of water to be isotonic
** If you have just the potassium value, either multiply by 1.9 to get the weight of potassium chloride, or use 169 ml/g of potassium.
=References=
<references>
<ref name="Moseley-2003">{{Cite journal | last1 = Moseley | first1 = L. | last2 = Lancaster | first2 = Moseley, GI. | last3 = Jeukendrup | first3 = Lancaster, AE. | title = Jeukendrup, Effects of timing of pre-exercise ingestion of carbohydrate on subsequent metabolism and cycling performance. | journal = , Eur J Appl Physiol | , volume = 88 | , issue = 4-5 | , pages = 453-8 | month = , Jan | year = 2003 | , doi [http://dx.doi = .org/10.1007/s00421-002-0728-8 10.1007/s00421-002-0728-8 | ], PMID = [http://www.ncbi.nlm.nih.gov/pubmed/12527977 12527977 }}]</ref><ref name="Jeukendrup-2010">{{Cite journal | last1 = Jeukendrup | first1 = AE. | last2 = Killer | first2 = Jeukendrup, SC. | title = Killer, The myths surrounding pre-exercise carbohydrate feeding. | journal = , Ann Nutr Metab | , volume = 57 Suppl 2 | issue = | , pages = 18-25 | month = , | year = 2010 | , doi [http://dx.doi = .org/10.1159/000322698 10.1159/000322698 | ], PMID = [http://www.ncbi.nlm.nih.gov/pubmed/21346333 21346333 }}]</ref>
<ref name="Brun">[http://www.alfediam.org/media/pdf/RevueBrunD&M5-2000.pdf J.F. Brun, C. Fedou, J. Mercier, "Postprandial Reactive Hypoglycemia," ''Diabetes & Metabolism'' (Paris) 2000, 26, 337-351]</ref>
<ref name="Brouns-1989">{{Cite journal | last1 = F. Brouns | first1 = F, NJ. | last2 = Rehrer | first2 = NJ, WH. | last3 = Saris | first3 = WH, E. | last4 = Beckers | first4 = E, P. | last5 = Menheere | first5 = P, F. | last6 = ten Hoor | first6 = F. | title = , Effect of carbohydrate intake during warming-up on the regulation of blood glucose during exercise. | journal = , Int J Sports Med | , volume = 10 Suppl 1 | issue = | , pages = S68-75 | month = , May | year = 1989 | , doi = [http://dx.doi.org/10.1055/s-2007-1024956 10.1055/s-2007-1024956 | ], PMID = [http://www.ncbi.nlm.nih.gov/pubmed/2663744 2663744 }}]</ref><ref name="Kuipers-1999">{{Cite journal | last1 = Kuipers | first1 = H. | last2 = Fransen | first2 = Kuipers, EJ. | last3 = Keizer | first3 = Fransen, HA. | title = Keizer, Pre-exercise ingestion of carbohydrate and transient hypoglycemia during exercise. | journal = , Int J Sports Med | , volume = 20 | , issue = 4 | , pages = 227-31 | month = , May | year = 1999 | , doi [http://dx.doi = .org/10.1055/s-2007-971122 10.1055/s-2007-971122 | ], PMID = [http://www.ncbi.nlm.nih.gov/pubmed/10376478 10376478 }}]</ref>
<ref name="malto">http://www.arniebakercycling.com/pubs/Free/Nutrition%20Maltodextrin%20SS.pdf </ref>
<ref name="Gray1971">{{cite journal|last1=Gray|first1=G M|title=Gray, Intestinal Digestion and Maldigestion of Dietary Carbohydrates|journal=, Annual Review of Medicine|, volume=22|, issue=1|year=, 1971|, pages=391–404|, ISSN [http://www.worldcat.org/issn=/0066-4219 0066-4219|], doi [http://dx.doi=.org/10.1146/annurev.me.22.020171.002135 10.1146/annurev.me.22.020171.002135}}]</ref><ref name="Rowlands-2008">{{Cite journal | last1 = Rowlands | first1 = DS. | last2 = Thorburn | first2 = Rowlands, MS. | last3 = Thorp | first3 = Thorburn, RM. | last4 = Broadbent | first4 = Thorp, S. | last5 = Shi | first5 = Broadbent, X. | title = Shi, Effect of graded fructose coingestion with maltodextrin on exogenous 14C-fructose and 13C-glucose oxidation efficiency and high-intensity cycling performance. | journal = , J Appl Physiol | , volume = 104 | , issue = 6 | , pages = 1709-19 | month = , Jun | year = 2008 | , doi [http://dx.doi = .org/10.1152/japplphysiol.00878.2007 10.1152/japplphysiol.00878.2007 | ], PMID = [http://www.ncbi.nlm.nih.gov/pubmed/18369092 18369092 }}]</ref>
<ref name="isotonic"> http://jap.physiology.org/cgi/content/full/85/5/1941 Hypertonic solutions are less easily absorbed</ref>
<ref name="JacksonTaylor2012">{{cite journal|last1=Jackson|first1=Brian P.|last2=Taylor|first2=Jackson, Vivien F.|last3=Karagas|first3=Taylor, Margaret R.|last4=Karagas, Tracy Punshon|first4=Tracy|last5=Cottingham|first5=, Kathryn L.|title=Cottingham, Arsenic, Organic Foods, and Brown Rice Syrup|journal=, Environmental Health Perspectives|, volume=120|, issue=5|year=, 2012|, pages=623–626|, ISSN [http://www.worldcat.org/issn=/0091-6765|0091-6765], doi [http://dx.doi=.org/10.1289/ehp.1104619 10.1289/ehp.1104619}}]</ref>
<ref name="Sweetness">Sweetness http://biology.clc.uc.edu/courses/bio104/carbohydrates.htm</ref>
<ref name="Jeukendrup2004">Asker E Jeukendrup, Carbohydrate intake during exercise and performance, Nutrition, volume 20, issue 7-8, 2004, pages 669–677, ISSN [http://www.worldcat.org/issn/08999007 08999007], doi [http://dx.doi.org/10.1016/j.nut.2004.04.017 10.1016/j.nut.2004.04.017]</ref>
<ref name="Jeukendrup2010">Asker E Jeukendrup, Carbohydrate and exercise performance: the role of multiple transportable carbohydrates, Current Opinion in Clinical Nutrition and Metabolic Care, volume 13, issue 4, 2010, pages 452–457, ISSN [http://www.worldcat.org/issn/1363-1950 1363-1950], doi [http://dx.doi.org/10.1097/MCO.0b013e328339de9f 10.1097/MCO.0b013e328339de9f]</ref>
<ref name="Van Thienen-2009"> R. Van Thienen, K. Van Proeyen, B. Vanden Eynde, J. Puype, T. Lefere, P. Hespel, Beta-alanine improves sprint performance in endurance cycling., Med Sci Sports Exerc, volume 41, issue 4, pages 898-903, Apr 2009, doi [http://dx.doi.org/10.1249/MSS.0b013e31818db708 10.1249/MSS.0b013e31818db708], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19276843 19276843]</ref>
<ref name="Hoffman-2008"> JR. Hoffman, NA. Ratamess, AD. Faigenbaum, R. Ross, J. Kang, JR. Stout, JA. Wise, Short-duration beta-alanine supplementation increases training volume and reduces subjective feelings of fatigue in college football players., Nutr Res, volume 28, issue 1, pages 31-5, Jan 2008, doi [http://dx.doi.org/10.1016/j.nutres.2007.11.004 10.1016/j.nutres.2007.11.004], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19083385 19083385]</ref>
<ref name="Artioli-2010"> GG. Artioli, B. Gualano, A. Smith, J. Stout, AH. Lancha, Role of beta-alanine supplementation on muscle carnosine and exercise performance., Med Sci Sports Exerc, volume 42, issue 6, pages 1162-73, Jun 2010, doi [http://dx.doi.org/10.1249/MSS.0b013e3181c74e38 10.1249/MSS.0b013e3181c74e38], PMID [http://www.ncbi.nlm.nih.gov/pubmed/20479615 20479615]</ref>
<ref name="Baguet-2010"> A. Baguet, K. Koppo, A. Pottier, W. Derave, Beta-alanine supplementation reduces acidosis but not oxygen uptake response during high-intensity cycling exercise., Eur J Appl Physiol, volume 108, issue 3, pages 495-503, Feb 2010, doi [http://dx.doi.org/10.1007/s00421-009-1225-0 10.1007/s00421-009-1225-0], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19841932 19841932]</ref>
<ref name="Sweeney-2010"> KM. Sweeney, GA. Wright, A. Glenn Brice, ST. Doberstein, The effect of beta-alanine supplementation on power performance during repeated sprint activity., J Strength Cond Res, volume 24, issue 1, pages 79-87, Jan 2010, doi [http://dx.doi.org/10.1519/JSC.0b013e3181c63bd5 10.1519/JSC.0b013e3181c63bd5], PMID [http://www.ncbi.nlm.nih.gov/pubmed/19935102 19935102]</ref>
<ref name="Derave-2007"> W. Derave, MS. Ozdemir, RC. Harris, A. Pottier, H. Reyngoudt, K. Koppo, JA. Wise, E. Achten, beta-Alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters., J Appl Physiol, volume 103, issue 5, pages 1736-43, Nov 2007, doi [http://dx.doi.org/10.1152/japplphysiol.00397.2007 10.1152/japplphysiol.00397.2007], PMID [http://www.ncbi.nlm.nih.gov/pubmed/17690198 17690198]</ref>
</references>
