Carb conundrum: too many carbohydrates will make you fat, too few will stunt your growth—here's how to manage your body's carb-storage ability for maximum results

Flex, Jan, 2006 by Chris Aceto

Implicated as a main culprit in promoting expanding waistlines, damned by the media and weight-loss gurus and demonized during the flood of low-carb food products that once hit store shelves, carbohydrates have gotten a really bad rap.

In our tight-knit bodybuilding circles, as well, carbs are a bastard stepchild to protein. Although our firm belief in the power of protein isn't going to dissipate anytime soon, we must admit this: carbohydrates are nearly as powerful as protein in determining the way a body responds to training.

Blasphemy? Stick with us, and we'll explain.

JUST THE FACTS, MAN | It's true that protein supplies the essential building blocks for muscle gains, but carbohydrates provide critical support of the body's growth processes in both mass-building and fat-shedding phases. An insufficient intake of carbohydrates during a strict diet can lead to a loss of lean tissue. When you're bulking up, carbohydrates help lower cortisol levels, increase testosterone levels, boost insulin and assist in funneling protein and other nutrients into your muscles.

To a large extent, your success at building mass or burning bodyfat boils down to your glycogen status. Glycogen is the name for the stored or unused carbohydrates in your muscles. When you take in more carbs at a meal than your body needs, some of the excesses are driven into your liver and muscles where they are stored for later use. On the flip side, when you eat fewer carbs than your body has an immediate need for, your glycogen levels fall as stored supplies are burned for energy.

Bottom line: keeping up your glycogen stores is important--the more effective you are at this balancing act, the more effective you'll be at attaining your fitness goals. Here are six facts about glycogen management that will help you in your pursuit of a rock-solid physique.

FACT #1 | The more water you can get into muscle, the more likely it is to grow. Drinking water to avoid dehydration is important, but eating a lot of carbs is also vital in the quest for mass. Carbohydrates bind with water when they form muscle glycogen; increasing glycogen stores in your muscles pulls more water into muscle cells, helping to boost your growth response to training. This effect is believed to be from the stretching of muscle-cell walls caused by the increased volume of water inside.

FACT #2 | Glycogen stores vary from bodybuilder to bodybuilder. In general, the bigger the guy, the more carbohydrates he can eat. Larger guys--with large amounts of muscle mass--have greater glycogen-storing capacity than smaller dudes. However, lean people are better at transforming carbs into muscle-glycogen stores, while heavier people tend to store a greater portion of their carb intake as bodyfat.

The take-home message is that larger or leaner bodybuilders have greater carb needs and bigger glycogen storage tanks. In a quest to gain mass, leaner bodybuilders should often emphasize a high-carb diet. If you're thin or have an easy time staying lean, your fuel-burning capacity may make it difficult for you to keep glycogen stores full.

An average bodybuilder needs about two grams (g) of carbs per pound of bodyweight a day for maintenance. If you're a hardgainer or if you're very muscular, you may need more than 2 g of carbs per pound of bodyweight each day--as much as 3-4 g--just to maintain your bodyweight and muscle mass.

FACT #3 | Glycogen powers your training efforts. When you hit the gym, you largely burn the carbs that you ate yesterday and the day before. You don't necessarily burn the carbs that you ate just before the workout or even earlier that day. That's because weight training relies on muscle glycogen (stored carbs) as the primary source of energy. If you follow a high-carb diet and have adequate glycogen stores, you should be able to train harder and longer than when you follow a lower-carb diet.

FACT #4 | Timing is everything. There are two times of day that your body is really good at driving carbohydrates into muscles to make new muscle glycogen: first thing in the morning and after training.

It makes sense to eat a large amount of carbohydrates at breakfast because, while you were sleeping, your glycogen stores tended to decline. More important, the amount of carbs circulating in your bloodstream--called blood sugar--also dipped. In that glycogen-depleted state, your body is more effective at taking the carbs you eat and storing them in muscles, upping glycogen reserves.

Posttraining is the other period when your glycogen-storing ability peaks. Training relies heavily on carbs for fuel, depleting both muscle glycogen and the concentration of blood sugar in your bloodstream. A high-carb postworkout meal will keep your glycogen stores and growth on track.

FACT #5 | Managing your glycogen stores can help burn fat. Although high glycogen stores are great for building mass, as an undesirable side effect, the body also becomes better at building up bodyfat when glycogen stores become topped off. On the flip side, as glycogen stores drop, the body starts to favor fat burning. If you're trying to get cut, you have to burn through your glycogen stores, and that means eating fewer carbs.