Photo courtesy of Mike Warren
Athletes have been practicing carbo loading since the late 1960s. But what’s the big deal with carbo loading? What the heck is it? Why do it? Is it really worth the effort?
The short answer is that carbo loading enhances endurance performance by increasing the amount of glycogen in the body. More glycogen (Carbohydrates) stored in the muscles and livers equates to more energy at an athlete’s disposal.
The benefit? You’ll last longer in an extended endurance event!
In practice the body normally has enough Glycogen for events up to 90 minutes in duration. But if you are doing an extended event like a Marathon, there are some obvious benefits to extra glycogen stores.
So how does one carbo load? There are various carbo loading practices, which have changed over time with new Scientific findings. These are elaborated on at great length in an article I discovered the other day titled The evolving art of carbo-loading.
A Swedish physiologist named Gunvar Ahlborg was the first to introduce some scientific basis to the fact that the muscles and liver are able to store above-normal amounts of glycogen when high levels of carbohydrate consumption are preceded by severe glycogen depletion.
The stress of severe glycogen depletion triggers an adaptive response by which the body reduces the amount of dietary carbohydrate that it converts to fat and increases the amount of carbohydrate that it stores in the liver and muscles as glycogen -a phenomenon Ahlborg referred to as glycogen supercompensation.
From his findings he developed The Ahlborg method:
- Perform an exhaustive workout one week before a long race (90 minutes-plus).
- Consume a very low-carb diet (10%) for the next 3-4 days while training lightly.
- Consume a very high-carb diet (90%) the next 3-4 days while continuing to train lightly.
Endurance athletes around the globe began to use Ahlborg’s carbo-loading plan prior to events anticipated to last 90 minutes or longer.
While it worked, it had its share of drawbacks. Many athletes weren’t keen on performing an exhaustive workout just a week before a big race. Also maintaining a 10 percent carbohydrate diet for three or four days carried some nasty consequences including lethargy, cravings, irritability, lack of concentration and increased susceptibility to illness.
Fortunately research later offered an alternative method that increased glycogen storage without first depleting it.
The no-depletion method came onto the scene:
- Perform a long workout (but not an exhaustive workout) one week before race day.
- Eat normally (55-60% carbohydrate) until three days before a longer race.
- Eat a high-carb diet (70%) the final three days before racing while training very lightly.
The method was more pleasant to athletes and carried fewer of the risks associated with the Ahlborg method. Athletes were no longer required to perform a long depleting workout a week before a big race!
However, in 2002, however another method was devised by scientists at the University of Western Australia. This was perhaps the easiest method of all to follow as it only involved one day of preperation:
- During the pre-race week, eat normally while training lightly until the day before a longer race.
- On the morning of the day before the race, perform a very brief, very high-intensity workout. (In testing this consisted of two and a half minutes at 130 percent of VO2max (about one-mile race pace) followed by a 30-second sprint).
- Consume 12 g of carbs per lb. of body weight over the next 24 hours.
The result? A 90-percent increase in muscle glycogen storage!
The method works best if preceded by a proper taper – several days of reduced training with the purpose of rendering your body rested, regenerated and race-ready.
So when should you use Carbo Loading?
Carbo-loading in general has been shown to enhance race performance only when athletes consume little or no carbohydrate during the race itself. If you do use a sports drink or sports gels to fuel your race effort – as you should – prior carbo-loading probably will have no effect. But it doesn’t hurt to do it anyway, as insurance.