Gels (GU, Hammer Gel, Clif Shot) are handy on long training runs.  I like to have calories on hand for distances over 10 miles on the road or over about 75-80 minutes on trails.  I've used GUs and Clif Shots and like them both.  They are light, compact, and convenient.  The downside is that gels, and energy bars for that matter, are expensive.  I like cheap.  I also like tinkering. 

The nutrition info on the label boils down to maltodextrin and amino acids.  Maltodextrin is a carbohydrate; that's the fuel.  And the amino acids?  Leucine, valine, isoleucine, and histadine are listed in the GU nutrition info.  Clif Shot lists none, although it does list electrolytes (salts like magnesium and potassium).  Given that these are competing products the difference in content caused me to question the importance of the amino acids.  Further digging turned up a great series of three podcasts by six-time Ironman champion Dave Scott where he talks about replacing calories during training and racing.  In addition to his advice the site provides associated charts (taken from from the book, The Performance Zone: Your Nutrition Action Plan for Greater Endurance & Sports Performance by Dr. John Ivy, Ph. D, and Dr. Robert Portman, Ph D.) that pretty much lay out exactly what should be in a sports drink.  Fair warning - the podcast site is sponsored by Accelerade.  Nevertheless, the details are there and agree with the other sources I found both on the web and in research journals.  So apparently carbohydrates and proteins in a 4:1 ratio along with some salts and a little vitamin C is what should be in a sports drink.  And what is a gel if not a  super-concentrated sports drink?

An exhausting, if not exhaustive, search of local and online sources led me to BulkNutrition.com as a source for both maltodextrin and whey protein.  Whey protein is complete (contains all 20 amino acids) and has the highest biological value of any known protein source.  I ordered the maltodextrin and whey protein made by Now Foods.  The whey protein mixture itself contains some carbohydrates as it is intended for use as a drink mix.  Based on my calculations to account for the carbohydrates in the whey protein mix, 90g of maltodextrin and 40g of whey protein mix would combine to yield five 100 calorie servings with the overall 4:1 ratio of carbohydrate to protein.

If you’ve never seen an energy gel imagine pancake syrup, only thicker.  How do you get from 130g of powder to 5oz. of thick gel?  This is one detail I still haven’t figured out.  I mixed my 90g of maltodextrin and 40g of whey powder with 5oz. of bottled water.  I tried using less water, but when I did the mixture was too thick to stir.  Heating the mixture seems like an obvious answer, but I was and still am afraid of degrading the amino acids.  In my former life as a biologist I autoclaved bacterial media all the time, but I’m not sure what the crucial temperature would be.  If you have any suggestions or experience please leave a comment.  In the meantime, I coaxed the thick, mildly sweet mixture into newly purchased, empty 2 oz. shampoo travel tubes from Walmart. 

Voila, energy batter.

I’ve gone through a couple of batches of this stuff so far.  It’s not optimal, but it works.  I estimated the price per 100 calories to be under 30 cents as opposed to just over a dollar for a GU or Clif Shot.  That kind of savings adds up when you start using a half dozen or more of these a week.  My next experiment will be to see if I can make a maltodextrin only style gel ala Clif Shot by boiling the solution.