* Sustained Energy is neutrally (a.k.a. "plain") flavored. Perpetuem is available in two options: an orange-vanilla "Dreamsicle" flavor and in an unflavored/plain version.
* Perpetuem contains lyso-lecithin fat, whereas Sustained Energy does not.
* Perpetuem contains tribasic sodium phosphate, which is a tremendous lactic acid buffer. Sustained Energy does not contain this nutrient.
* Both fuels contain l-carnosine (an antioxidant that also buffers lactic acid), l-carnitine (to promote fatty acid utilization) , and chromium polynicotinate (to stabilize blood sugar levels).

Bottom line: With Sustained Energy and Perpetuem, you have two great long distance fuel choices. When exercise goes beyond about two hours, you can use either product as your primary or sole fuel, in any combination with each other or any other Hammer Nutrition fuel.

We introduced Sustained Energy in the early 90's (1992 I believe) and we continue to make it, not just because it's a great, time-tested fuel, but also because it has been and continues to be the preferred long distance fuel for literally thousands of athletes. Perpetuem was introduced in early 2003 after thorough testing, with its "acid test" being the Double Furnace Creek 508. In that record attempt I used Perpetuem as my primary fuel but I also used Sustained Energy as well...
they both worked wonderfully and, along with Hammer Gel on occasion, I had a nice variety in my high quality fuel "menu."

All that said, I personally tend to believe that the longer one goes the more appropriate the use of Perpetuem becomes, primarily via the two components it contains, sodium phosphate and lyso-lecithin fat, which Sustained Energy does not contain. Again though, they are fairly similar fuels and can be used in similar circumstances.

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Steve Born
Senior Technical Advisor
Event Sponsorship Coordinator
www.hammernutrition .com
800.336.1977
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