Eric,

I think if you explained the carb loading/re-feeding process, most would find that interesting.  From the science behind it, to when to implement it, frequency, how much carbs, etc.  I think it would make for a good article.

Luis

Luis,

The processes of carb loading and re-feeding are quite interesting, I wholeheartedly agree. Depending on whom you are talking to and in what context you are discussing the topics, you will get a wide variety of responses. Carb loading and re-feeding are actually two different subjects.

To begin, lets discuss carb loading and its origins, purposes, and a general how to. Carb loading has its place in both performance sports and the cosmetic sport of bodybuilding.

Carb loading for performance is normally utilized in endurance sports. Marathon runners, cyclists and other endurance athletes utilize carb loading to improve their performance. Normally these athletes load on low glycemic carb sources due to their minimal effect on serum glucose levels. It is very common to see an Italian restaurant packed the night before a big local race.

The original carb loading procedure that athletes followed started seven days before the event. The athlete would engage in a training bout designed to deplete their glycogen stores and then for the following two to three days they would perform moderate amounts of exercise and keep their carb intake low to ensure low muscle glycogen levels. Then, three to four days before the event they would begin eating a very high carb diet. This process is called depletion and super compensation. By starving the body of carbohydrates, it will initiate a response that allows the muscles to store larger than normal amounts of glycogen when they are reintroduced. The manipulation of this survival mechanism allows the body to store more energy for the coming competition.

There are also carb loading strategies that don’t require depletion. In the 1980s, research led to a modified regimen that called for increasing carbohydrate intake to about 70% of total calories and decreasing training for three days before the event without prior depletion.  Most athletes now follow this modified protocol.

One of the most cutting-edge carb loading regimens was developed by scientists at the University of Western Australia. This process calls for following a normal diet and performing only light training until the day before the event. On that day, the athlete would perform a bout of high intensity cardio, such as sprinting, for a very short duration. This would be followed by consuming 12 grams of carbohydrate per kilogram of lean body mass over the next 24 hours. This regimen has shown to increase glycogen storage by 90%.

Bodybuilders utilize carb loading strategies too, however they do this not for performance but because muscles full of glycogen are bigger, fuller and appear more impressive. When bodybuilders originally began carb loading they copied the basic format of the depletion and super compensation protocol that endurance athletes were using at the time. However, as the sport has evolved we have come to see a number of problems with this strategy.

First off, super compensation tends to cause what is known as “spilling over”. Spilling over is essentially when one eats more carbohydrates than their muscles can store which results in glucose moving into the subcutaneous space between the muscle and skin. Spill-over blurs definition and can make a bodybuilder appear less lean. For every gram of carbohydrate that enters the muscle, it attracts roughly three grams of water. So when you overload on carbohydrates those grams of glucose that “spill” into the subcutaneous layer bring a film of water with them. This is why many competitors believe they must cut their water, or use diuretics in order to avoid the spilled-over look when attempting to super compensate with a carb load.

The belief that one needs to cut water to avoid spilling-over is flawed in its premise, dangerous in its practice and actually makes you look worse. Remember, for every gram of carbohydrate there are three grams of water that come with it. If you eliminate the water you are actually eliminating the vast majority of what is making the muscle appear full! Next time you think of cutting water, compare beef jerky to a lean cut of sirloin. Which would you rather have your muscles look like? It is the water that primarily makes one appear full, not the carbohydrates.

Hydrated Sirloin

Dehydrated Sirloin

In general, if you attempt to deplete and super compensate you most likely will spill over. This occurs because you are following a protocol originally intended for endurance athletes. These athletes never cared what they looked like, only how they performed. So overshooting their carb intake was prudent to ensure maximal glycogen storage. For a bodybuilder it is not prudent, it is risky and can negate weeks of hard work.

A more reliable, consistent approach is to either use a much more conservative version of the depletion and super compensation technique, or to simply increase carb intake one or two days before the show and adjust carb levels according to one’s fullness on show-day. This tends to be extremely variable from person to person. Muscle glycogen storage adapts to the amount of carbs in the diet and to the type and amount of exercise being performed. So, the speed of one’s metabolism, the amount and type of activity and exercise and the amount of carbs currently in the diet, causes much variability in an individual’s carb loading process.

Re-feeding is a related topic, but it has entirely different purposes and applications. The purpose of a re-feed is to ensure that fat loss continues, training stays effective, and muscle mass is maintained.

As one continues a diet their metabolism slows down. A delicate hormonal balance is disrupted when one embarks on being in a caloric deficit for an extended period and gets to stage-levels of body fat.  It becomes increasingly difficult as time goes on to continue to lose body fat at the same rate as the body begins to resist this process hormonally. A significant increase in total calories in the form of carbohydrate can up-regulate fat burning hormones, thus counteracting the metabolic slow down to a certain degree. In general, increasing calories to, or above maintenance levels primarily in the form of carbs once or twice weekly is how this is implemented in contest preparation diets. Again, this process has a high degree of individual variability. How resilient one’s metabolism is, where their body fat set point resides, what type of training plan they are following, their age, gender, activity, insulin sensitivity and a host of other variables all come into play when setting up an individual’s re-feed schedule.

There are also different schools of thought regarding re-feeds. Some believe re-feeds should be implemented on days which you train your weakest body part. The idea here is that the increased energy levels will provide a better workout and there will be a localized increase in glycogen storage in those muscles trained and for both reasons, you will retain more muscle mass in your weak areas.

Another idea is to place a scheduled re-feed on your most energy-demanding day. The thought process being that you will ensure the increase in calories causes minimal body fat storage. This strategy acknowledges that to get to very low levels of body fat, an over aggressive re-feed (especially for those bodybuilders who have a difficult time getting in condition or are behind) can sometimes cause more harm than good.

Finally, there is the notion that your scheduled re-feed should be placed on a day of rest. This ensures you are storing as many of the carbohydrates as possible as glycogen so that you get the biggest boost in performance. It also is more likely that you will be eating above maintenance levels and thus would get the best hormonal response in order to continue the fat burning process.

In truth, all three strategies have their place and purpose. A competitor who has a tough time holding onto muscle in certain body parts could benefit from the first strategy. A competitor, who holds onto muscle well but is behind schedule as far as conditioning, could benefit from the second strategy. And lastly, a competitor with a very non-resilient metabolism but who has plenty of time to get in condition, could benefit from the final strategy. Again, as with most aspects of this sport, a high degree of individual variability exists.

Do you have a bodybuilding question for Eric? Send your questions to erichelms@3dmusclejourney.com

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