Fat as fuel

Fat as fuel: a review of VESPA CV-25

Fat: Most athletes, through coaching and self-study/research, have been traditionally hardwired to believe that this is primarily causal to substandard performance, excess weight, and general lack of health. As health science continually emerges and evolves, though, this vilification of fat has become suspect. In fact, some self-proclaimed heretics, like Peter Defty of VESPA and Prof Tim Noakes, claim that fat (rather than carbohydrate) is, in fact, the principle source for fueling in endurance and ultra-endurance sports. So how can we make the most of fat as fuel?

Enter VESPA, stage right. VESPA is based on the idea that humans, like many other species, store an almost infinite amount of energy as fat whereas they can only store about 90 minutes of energy from carbohydrate (glucose stored in muscles and liver). VESPA serves as a catalyst to the metabolic pathway which converts our fat stores to useable energy (a process known as ketosis and beta-oxidation). If you think of your body as a car engine, carbohydrate is gasoline – fast burning fuel for immediate results and instantaneous power. On the other side of the energy spectrum, fat burning would be likened to diesel fuel – slower to initiate speed and power, but long burning and heavy hitting in the long run. VESPA serves as a bridge between these two fuel types in an effort to maximize the power-efficiency-longevity ratio that your muscles are capable of – making a sort of gas/diesel hybrid.

The catalyst (what kicks our bodies into fat-burning mode) of the VESPA product is the extract of the Asian Mandarin Wasp (Vespa mandarina). Essentially, this wasp flies upwards of 100km in a day on nothing more than fat stores from its thorax in order to feed its offspring. The larva of the wasp lives in symbiosis with its parent, providing the adult wasp with a peptide which allows for the breakdown of the fat for fuel. VESPA harvests this same peptide from the larvae, and under the pretense that individual cells are similar inter-species, allows human cells to function in the same fashion.

In conjunction with the use of VESPA, Peter Defty devised OFM (Optimized Fat Metabolism), a comprehensive program which predisposes your body to burn fat as a standard fuel. This allows for the most benefit from supplementing with VESPA in both training and competition. In essence, the nutrition strategy calls for limitation of carbohydrates, especially “white” carbs (potatoes, bread, etc.) and an influx of “good fats” (avocados, nuts, and natural fats including saturated fats, etc.) to be allowed. Note that this does not entirely eliminate carbohydrates from your diet, and instead advocates the “strategic” use of carbs – basically before and during competitions.


I’ve been using VESPA for nearly a full year now (I sat down for the first time with Peter Defty in February of 2014), and as a prelude to the nitty-gritty of the review, I’d like to make note of the fact that I do no longer consciously strive to maintain an OFM diet. I found that simply by limiting my carbohydrate intake, my protein-fat-carb ratio self-adjusted to be moderate, high, and low respectively. I would say, though, that if you’re intending to experiment with the product and eventually include it in your dietary regimen, you should begin with a strict low carb, high fat type diet – sort of a modified paleo style nutrition plan – until you become better “fat-adapted” (to be able to use fat as a primary fuel source).

**CV-25 is intended for athletes of over 160 pounds. VESPA Junior has a lower content of Wasp extract and may be better suited to athletes under 160 pounds. Also available is a VESPA Ultra-concentrate, which is only recommended for athletes who have used VESPA CV-25 or Junior in the past.**


The CV-25 (as well as the Junior) is contained in a simple, aluminum/plastic style pouch, with a small bit-tip twist off cap. The package is reminiscent of a baby-food pouch, and fits well in the pocket of a race vest, but doesn’t do so well in a pair of shorts. For racing, I’d only recommend having a pouch in a drop bag or at a crew stop. If you absolutely need to carry a VESPA package with you, I’d opt for the smaller Ultra-concentrate which is packaged in a small, rip top package similar to a fast food condiment packet.


In my opinion, taste is, by far, the biggest downfall of the product. While not altogether unsavory, the taste of the CV-25 mixture is only slightly reminiscent of honey and is, in fact, relatively bitter making it slightly less than enjoyable on first sip. I find that I have to consume VESPA in one gulp and promptly drink a mouthful or two of water/sports drink to wash away the taste. It is far better cold than room temperature or warm, and I try to refrigerate the package before consuming if at all possible (obviously race logistics might make this difficult to impossible).

On the other hand, texture is not nearly an issue. The compound is a fluid – watery, and easily palatable even mid run.

Benefits/Positive Results –

Most notably, of all the results, is my decreased need for mid-run calorie intake. This makes a world of difference, not only in the overall amount of storage necessary for my runs, but also in the gastronomical side effects of consuming sticky-sweet gels. I find that during a training run, I can easily manage a steady pace on even the most diverse of terrain with not much more than 100 calories per hour and some sodium. During races, I tend to increase my intake to about 200-300 calories per hour (some of which is from “real food”) and salt.

Because of this limited intake and requirement, I almost never carry a race vest for races of 50 miles or less – carrying nothing more than a handheld water bottle, a gel or two, maybe an EPIC Bar, and whatever’s on my back. This allows me to move all the more easily and remain nimble & unhindered over technical descents and upright and unimpeded on uphill climbs.

Additionally, because I only have water and a gel or two bouncing around, I no longer experience bloating or upset stomach mid-run. This really hasn’t been a huge issue for me in the past, but it has come up a few times; when it did it was entirely debilitating and I know that it’s a common discomfort for endurance and ultra-endurance athletes.

Furthermore, I’ve noticed a slight increase in my propensity for recovery, most notably in the level of muscular soreness I feel post-run. This is most likely due to the fact that my body is not producing nearly as much lactic acid as it would be if it were fueling entirely on carbohydrate stores.

There are other purported benefits, like increased mental clarity and alertness, of which I have not noticed a tangible difference. Ultimately, I still feel like I’ve run 30 miles when I’m done running 30 miles, like I’ve run 50 miles when I’ve covered 50 miles.

Drawbacks/Negative Results –

I’ve already mentioned my distaste for the flavor, but there are a few other setbacks I’ve made note of over the past year:

First, if you haven’t cut your carb intake, you may experience an upset stomach. For example, last spring I had just encountered Skratch Labs Hydration Mix and Portables. Most of the Portables recipes are in rice cake form, and because I was experimenting with recipes, I had been eating a LOT of rice in the week or two prior to my long run. I won’t go into the gruesome details, but ultimately I stopped several times on the way home from the trailhead.

Second, the packaging, like I explained earlier, can really only be held in the pocket of a race vest. Functionally, for me, that doesn’t work so well. I’ve resorted, then, to only have VESPA packets available at Drop Bag or Crew Accessible points.

Third, and probably the most important, is that hydration plays a HUGE part in the entirety of fat burning, and therefore in the use of VESPA. Essentially, from my limited understanding of the process, ketosis requires an abundance of electrolytes (primarily in the form of sodium chloride, salt). Without active supplementation, this takes sodium and other salts away from the muscles (which use electron shedding/collection from sodium and potassium to contract and expand muscle cells/bundles) bones, and liver. This also affects your ability to thermo-regulate via sweat. The first few times I used VESPA, I was not a master at hydration, and as such, suffered irreparably from dehydration and cramps. At about the 30 mile mark of the American River 50 Mile Endurance Run, for example, I began to experience what can only be described as a series of muscle cramps which felt as if someone were playing my muscle strands like a rhythm guitar. By the end of the race, because I had failed to properly hydrate, my calf muscles twitched involuntarily and eventually seized up; it felt like a grapefruit or softball had taken their place. So long as you heed the warning on VESPA’s website, though, you can pretty easily avoid this kind of discomfort.

Conclusion –

Accepting that VESPA’s product, like any other product will have negatives and drawbacks, and based on my personal experience, I’ve concluded that VESPA is a product of note to say the least. On the whole, I feel that the benefits (and subsequent consequences of those benefits) of VESPA far outweigh the drawbacks – so much so that I use, and will continue to use into the foreseeable future to harvest fat as fuel, VESPA’s product for long runs and on race day (I limit my use to only these two parameters in an effort to continue to expand my fat and carb burning efficiency, and most of my training runs do not exceed two hours).

If you have any questions regarding my experience with, my review on, or VESPA itself, please feel free to leave a comment below and I’ll be sure to get back to you with an answer as soon as possible. Otherwise, for more information or to order your box of VESPA, please visit www.vespapower.com or email info@vespapower.com.

Cheers, and Happy Trails,

 Product Details:

From the VESPA website: “Shake and consume one pouch of VESPA CV-25 or VESPA JR 45 minutes prior to athletic activity. You can consume VESPA with water or your favorite electrolyte drink. For endurance events and training lasting longer than 2 hours consume VESPA every 2-3 hours”.

**These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent disease.**


  • FilteredWater
  • Honey
  • Royal Jelly (240mg)
  • Citric acid
  • Bee propolis (120mg)
  • Wasp extract (100mg)
  • Ascorbic acid
  • Product: VESPA CV-25
  • Type: Supplement
  • Serving Size: 1 Packet (80ml)
  • Calories: 18
  • Calories from Fat: 0
  • Carbohydrate: 5g