BY STEVE BORN
There can be no doubt that the ketogenic diet is wildly popular these days. And for many people, it appears that this dietary practice can be beneficial for helping to lose unwanted weight. But when it comes to extending and improving endurance athletic performance, we're not big fans of low-carb diets for endurance athletes. Carbohydrates are the main source of fuel to produce energy, and it is our position that when we purposely cut back too much on our carbohydrate intake, it can have a negative impact on performance. We believe that adequate amounts of carbs are needed to ensure proper fat metabolism, especially during exercise and immediately after.
Fat burns in a carbohydrate flame
Dr. Rick Kattouf states, "Not only do carbohydrates provide energy for working muscles, they also assist in enabling fat metabolism. In short, carbohydrates need to be present in order for fat to be utilized for energy." 
Research  has shown that when carbohydrate levels are low, a substance known as pyruvate - which is formed during glucose metabolism - is unable to perform its job in the process of creating energy using oxygen (i.e. cellular respiration). When pyruvate is unable to perform its tasks - which it can only do in the presence of carbohydrates - the body's ability to use fat as a fuel source significantly slows down or halts altogether. This same research shows that without replenishment of adequate amounts of carbohydrates, the body will cannibalize specific amino acids (BCAAs, alanine) from muscle tissues, which not only slows down metabolism, it also causes excess production of fatigue-causing ammonia.
Perhaps the most compelling argument against low-carbohydrate diets comes courtesy of an excellent article by highly respected sports nutritionist, Dr. Gabe Mirkin . A key piece of the article reads:
Some people believe that if you restrict carbohydrates, you will teach your muscles to burn more fat and preserve their small store of sugar (Metabolism, 2016;65(3):100-10). That is correct, but burning more fat and less sugar for energy slows you down (Nutrients, 2014;6.7:2493-508). The limiting factor to how fast you can move over distance is the time it takes to move oxygen into muscles. Since sugar requires about 20 percent less oxygen than fat does to fuel your muscles, you need to slow down and have less power when your muscles burn fat rather than sugar.
Perpetuem's time-proven formula
Since its official introduction in 2003, Perpetuem has been put to the test in the most grueling events imaginable and come out on top. From its first test, the still-standing 15-year-old Double Furnace Creek 508 record to Deca Ironman to summiting Mount Everest to swimming the English Channel and everything in between, Perpetuem has proven to be the supreme ultra-fuel.
Perpetuem's 8:1 ratio of complex carbohydrates and soy protein isolate - plus a small amount of healthy fat - is EXACTLY what your body needs during long-duration exercise. Perpetuem's specifically designed formula provides the proper amount of carbohydrates, which allows your body to access and use the nearly limitless amounts of calories available from fatty acid stores, while also protecting against lean muscle tissue breakdown. The result is noticeably consistent, long-lasting energy hour after hour after hour.
While there may (key word may) be some general benefits to be accrued from the ketogenic diet, the fact is that carbs are still king when it comes to fueling your body during exercise, especially in regard to being able to use fat as an energy source most efficiently and effectively. That's why the Perpetuem formula is designed the way it is, with proper amounts of complex carbs, protein, and healthy fat - a meal in a bottle for enhancing endurance exercise performance.
For 15 years and counting, Perpetuem and its unique formula ruled supreme, fueling athletes superbly and ideally, helping them conquer every endurance/ultra-endurance event imaginable. Perpetuem: real fuel, not a fad.
 McArdle WD, Katch FI, Katch VL. Exercise Physiology Nutritional. Energy, and Human Performance seventh, edition. 2010
 Low-Carbohydrate Diets Harm Athletic Performance at http://www.drmirkin.com/fitness/lowcarbohydrate-diets-harm-athletic-performance.html