I just ordered some VESPA for myself but have not tried it yet. May endurance athletes rave about it. Below is some info I received through various emails with one of the owners.

Here is a little about VESPA
What we have found in "fat-adapted" athletes who use VESPA is that strategic use of concentrated forms of carbohydrates actually works best. I believe this is mentioned in The Art & Science of Low Carbohydrate Performance. You may want to play with that....for a marathon a typical dinner is a medium rare ribeye or NY steak and a small baked potato buried in butter, sour cream and salt.early the night before a long run like a marathon.

The morning of a race some tea or coffee with heavy cream and a teaspoon of honey or sugar and perhaps a sourdough English Muffin with lots of butter a few hours prior.

Suggested method for using VESPA for a marathon or half is a CV-25 an hour before the start, long slow warmup (LSW), then a VESPA Junior right before the start. Then another CV-25 at the half marathon to 16 mile mark and perhaps a gel at mile 18-22 if you are really going hard. Some people take a VESPA Junior at hour 1 and hour 2 instead.

Proper hydration is key and most athletes do not get enough salt. Supplementing with a bio-available form of Magnesium is also recommended.

VESPA/OFM (for Optimized Fat Metabolism) does make "Strategic" use of concentrated forms of carbohydrates in the diet and for race fueling....I believe this is mentioned briefly in the book in the section where they talk about VESPA.

What we have observed is that in fat-adapted athletes using VESPA the occasional use of carbs in the diet and fueling actually enhances performance significantly. . . . even carbs work much better and sustainably in an OFM athlete! Ironically, the carbs yield better results using significantly less than what the athlete had to use prior to becoming fat-adapted and using VESPA.

What I have observed and heard from working with athletes is that using strict low carb and UCAN they have the ability to motor at a relatively high rate for extended periods of time but do not have that "extra gear" necessary for racing level performance or surges and sprints but when using VESPA with some strategic use of carbs they definitely feel they have the extra gear.

Naturally occurring Magnesium Salt. Take one or two after your larger meals. Keep them dry. During really high training volume taking Epsom Salt baths is also recommended to maintain Mg levels. Mg is a bit tricky because it is easily depleted and most athletes with a relatively high training volume are somewhat deficient in Mg....however, it is not easily replenished like Sodium, Potassium or Calcium....too much intake results in diarrhea (think Milk of magnesia). ....

If you are well fat-adapted taking a VESPA 30 minutes prior to your run, doing a good warmup and in a fasted state you should have no issue going for 2.5 - 3 hours without calories...

VESPA literally makes a fat adapted athlete "Blood Sugar Stable" because one way it works is to drive ketosis to produce ketone bodies to be utilized in place of sugar....ketone bodies actually "burn" cleaner and with less oxidative stress for most brain and nervous system functions and the heart also easily utilizes ketones as an energy substrate...

Now here is the interesting thing.....we have a handful of T1 diabetic athletes who know about VESPA and they report their blood sugar remains rock stable during their exercise of 1-2 hours like a run or hockey game etc.

VESPA when combined with Low Carb allows the use of carbs and in doing so they work like never before.....