And every endurance athlete knows what happens to performance when their carbohydrate tank (at best holding 2000 Calories) runs dry – performance goes down in flames. It’s an unfortunate reality that the human body is unable to promptly switch from carbs to fat as its predominant exercise fuel, so once the former is gone, you can’t power your performance with fat (even though a carbohydrate-depleted body still has tens of thousands of fat Calories on hand).
The key fact underlying this book is that you can train your body to burn fat by simply changing your diet over a period of a few weeks, thereby turning blood sugar and glycogen into secondary fuels. Once you make this transition, you can then train harder, perform longer, and recover faster. So the simple answer to why we endorse a low carbohydrate lifestyle for athletes is that this strategy has worked for us and many people we know. More importantly, we have both conducted and published human research that supports this approach, adding to a growing body of literature that now points to the merits of reducing dietary carbohydrates to optimize fat metabolism. We have thus accumulated a unique knowledge base that we want to share so you too may experience it for yourself.