Runners have been using a technique in which they switch their diet from one that is low carb to one that is carb loaded, immediately before a race, in order to provide them with a fat loss and running performance boosting advantage. This has caused many people to wonder if they should be able to do the same thing to shed the extra pounds with exercising and switching their carb consumption habits.
So what is the truth behind this practice? For starters, it should be noted that while some runners may take on this practice, others don't believe in it at all. In fact, while some runners feel that switching to carb loading provides them with a lot of help, others don't believe in it at all. Science has, however, shown that instead of switching to a high carb diet, if endurance athletes change to a diet that is low in carbs but high in fats, then it can help them to avoid running into the energy crash that occurs if the runner doesn't fuel up again about halfway through their race.
Therefore, the primary debate is essentially one that is held between quality and quantity when it comes to the fuel that is being chosen for racing runners. Since muscles can store only a limited number of carbs at one time (approximately 2,500) but can store a lot more energy in fat (50,000 calories), it may actually be possible to adjust the diet in order to teach the body to use fat as a primary energy source by restricting carbs in order to avoid the exhaustion during a race for better running performance.
However, as much as that may seem to make sense, the problem is that burning fat is harder on the body so it can hurt the ability of an athlete to truly perform. Furthermore, if the body hasn't fully adapted by race day, then you can still end up hitting a wall, even if you are working on burning fat instead of carbs.
This is why many runners and dieters are choosing to compromise, to try to get the most out of their bodies from both carbs and fats. The idea is to train on a low carb and high fat diet for a stretch of five to ten days. That's long enough to switch your body over to burning fat as fuel. The balance of this type of diet should be about 50 percent of calories from healthy fats, 25 percent from proteins and 25 percent from carbs. Then, one to three days before the race, swap that for 80 percent healthy carbs, 10 percent healthy fats and 10 percent protein.
The idea is that the body has adapted to fat burning but that it hasn't forgotten how to burn carbs, too. Therefore, the concept behind this strategy is to train low on carbs so that fat will be burned as fuel more easily, but only when the easier-to-burn carbs have run out, avoiding the crash and improving running performance dramatically.