Protein gets all the glory when it comes to building muscle mass, and carbohydrates get all the blame when we talk about excess bodyfat. But the truth is, you need carbs to support muscle building, provide energy to fuel workouts and replenish the glycogen you burn during them. In fact, you also need a certain amount of carbs to help you lose bodyfat as readily as possible. If you cut carbs too low for too long when trying to drop bodyfat, you force your body to convert dietary protein and possibly even muscle tissue into energy. That works against your goal of maintaining and building muscle while following a fat-loss program.
Understanding what carbs are and how they function in your diet regimen is crucial if you want to get the most from advanced dietary techniques that involve carbohydrate manipulation. Regardless of your level of development as a bodybuilder, you must assess many variables to determine what you need and when. First you need to have a reasonable goal, such as losing bodyfat while maintaining muscle mass. In a perfect world, it would be great to lose bodyfat and add an equivalent amount of muscle, but that isn’t realistic for most people.
Second, it’s important to know that different types of carbs are digested at different rates and that they have various effects on insulin release and metabolism. You must also understand how other foods and macronutrients play a role in the way carbs impact your metabolism. Finally, MMI describes how different carb strategies can help you get the most from your nutrition program.
To help us explain all you need to know about this very basic yet complicated macronutrient, MuscleMag turns to author and sports nutrition researcher Jonathan Mike, PhD(c), CSCS, NSCA-CPT, USAW. Here’s what he had to say about how carbs relate to the bodybuilder and athlete.
Part I: The Basics
Before you implement a carb strategy in your bodybuilding nutrition program, it’s helpful to understand what carbs are and what they do.
FAQ: What are carbohydrates?
“Carbohydrates are one of the four major classes of organic compounds in living cells. The term ‘carbohydrate’ refers to saccharides, sugars and their derivatives,” explains Mike. Simple sugar molecules called monosaccharides include glucose, one of the most important forms of energy in living organisms. Disaccharides are carbohydrate molecules consisting of two monosaccharides. The most common of these is sucrose (table sugar), made up of a glucose and fructose molecule.
“Polysaccharides may be composed of up to hundreds of thousands of monosaccharides joined together,” Mike says. These include starch, cellulose and glycogen, and they serve many functions including storage and structural support. Some of these polysaccharides are digestible by humans, meaning they can be absorbed and used for energy. Others like insoluble fiber aren’t, even though they play crucial roles in the body despite the fact that they don’t “enter” it.
FAQ: What’s the purpose of carbs in a diet?
“Carbs are actually required for the complete metabolism of fatty acids,” Mike says. This means you must consume 50–100 grams of carbs per day to prevent ketosis, a metabolic acidosis that results from an accumulation of ketone bodies after excessive fat metabolism. This minimal amount of carbs equates to about 3–5 pieces of bread per day. Beyond this, the primary role of carbs in the body is to provide fuel for energy. “The amount of carbs needed by individuals and athletes depends on their total energy requirement, including expenditure,” adds Mike.
FAQ: What’s the purpose of carbs in an athlete’s or bodybuilder’s diet?
While athletes and bodybuilders have greater energy needs than sedentary people, this macronutrient plays different roles depending on your goal or needs. “The amount and purpose of carbs depends on the individual’s training schedule, volume of training, intensity, frequency of training and type of competition,” Mike says. This includes strength vs. endurance sports, as well as adjusting carb intake for bodybuilding needs (growth vs. cutting phases). “For mass building, increasing carbs helps boost overall caloric intake and replenish glycogen stores,” Mike explains. Glycogen is the stored form of carbs found in muscle tissue and the liver that helps fuel training. Having plenty of glycogen not only helps build muscle mass but can also boost strength and power.
“In addition, taking in carbs during exercise helps sustain blood glucose levels while sparing glycogen and helping stave off catabolism [muscle breakdown],” says Mike. There’s no one-size-fits-all approach in determining how many carbs you should consume to spare glycogen during weight workouts. Muscle-Mag’s guidelines below are designed for the average bodybuilder.
FAQ: We hear a lot of different terms for various types of carbs. What’s the best way to categorize them?
Foods are called “slow” or “fast” digesting, and this is crucial when it comes to carbs. “This has to do with the glycemic index [GI],” Mike explains. Foods with a GI score of 70 or higher are considered to have a high GI value; those below 55 are considered low on the GI. While this distinction may have merit when consuming these foods on their own, it’s often irrelevant when you mix in other foods high in fiber and fats, which reduce the insulin impact of high-GI foods.
To sum up: The best way to view carbohydrates is in the context of eating them alone or with other foods. When you want fast-acting carbs, eat these sources alone or with protein such as whey. When you want to slow the action of carbs, add fats and fiber to your meal. Some fast-digesting carbs include table sugar, honey, white rice, rice cakes and white bread. Some slow-digesting carb sources are yams, oatmeal, brown rice, and vegetables such as broccoli, cabbage and spinach.
FAQ: Why are carbs considered an anabolic nutrient?
“Good question,” Mike says. “Carbs cause an insulin release, which plays a crucial role in the metabolism of all macronutrients. You certainly need carbs for muscle building, but the issue is timing.” Our bodies have a unique ability to switch fuel sources for exercise and after exercise, called metabolic flexibility. They shift from fats to carbs and from carbs back to fats depending on the cues we send it. “For instance, as exercise intensity increases, your body shifts to more carb metabolism; after exercise the shift occurs back to more fat metabolism,” Mike explains.
The key word here is “intensity,” and here’s how it works: Around workout time, glucose transporters move to the surface of muscle cells and begin “pumping” glucose into them. Insulin also signals these muscle cells to shift to carbohydrate metabolism. “The energy status of these cells plays a large role in what happens within them,” Mike says. In other words, if your muscle cells are low on glucose and/or muscle glycogen, they’ll start using incoming glucose from your carb/protein shake (circulating blood glucose) for fuel and use any additional glucose to create muscle glycogen. “Furthermore, insulin will also stimulate an increased uptake of fatty acids into muscle cells,” Mike says. The end result is that you’ll use fat to build muscle tissue.
After workouts, insulin continues to drive anabolism. “At this point, insulin’s primary impact is believed to be helping your body push through catabolism more quickly,” Mike explains. This reduces the trauma caused by exercise and increases the muscle-building benefits of your workouts.
FAQ: Why does insulin increase body fat if it’s anabolic?
“If your muscle cells are already full of glucose and glycogen and are topped off with intramuscular triglycerides [fats], insulin signaling will continue to operate in a low-energy state but will also turn excess glucose into [body]fat,” Mike explains. This is most likely to happen at times of day when you aren’t training or refueling from training.
So, consuming a fast-digesting carb-and-protein combo after workouts is best for maximizing protein synthesis. At other times of day, avoid fast-digesting carbs (sugars) because they’re more likely to be stored as bodyfat and less likely to support muscle building.
Part II: Daily Carb Intake
In this section, we boils it all down to easy-to-follow charts, demonstrating how to adjust your carbohydrate intake to get the most from your training and nutrition programs to achieve your goals.
FAQ: When you’re trying to grow during the offseason, what type of carbs should you eat and when? How many should you consume per day?
“The answer to this question depends on many factors, including lifestyle, training volume and intensity, workout schedule, and routines and splits,” Mike says. Those who follow moderate and high-volume training protocols need greater amounts of both carbs and protein in their nutrition programs to meet their body’s needs.
“Consuming Carbs for Offseason Muscle Gain” addresses the daily needs of a 180-pound male bodybuilder emphasizing muscle building while trying to keep bodyfat somewhat in check.
FAQ: When you’re trying to shed bodyfat, how should you adjust your carb intake? What should you take in throughout the day?
“First, I recommend taking away a few hundred calories per day,” Mike says. “I would replace half of the calories you cut from carbs with fat calories.” For example, if you eliminate 1,000 calories from carbs, replace that with up to 500 calories from dietary fats. You’ll still create a deficit of 400–500 calories per day. “When you work under your baseline calories, then macronutrient ratios become much more important,” adds Mike.
“Consuming Carbs to Reduce Bodyfat” addresses the needs of a 180-pound male bodybuilder emphasizing cutting bodyfat while trying to maintain muscle mass. Note that daily carb consumption is about half compared to a muscle-building plan.
Part III: Advanced Strategies
We provide a baseline plan for carb consumption when you want to build muscle mass or reduce bodyfat. But you may also want to implement more advanced carbohydrate strategies, or better understand how and why carbs work. Here are a few advanced topics.
FAQ: How can I implement carb rotating to burn more body fat?
Carb rotation, or carb cycling, has gained popularity in recent years. “It appears to be a good strategy used by bodybuilders and physique competitors for both getting contest-ready and staying lean while adding lean mass, and it’s a decent strategy for fat loss,” Mike says.
Here are some bullet points to consider:
• Very low-carb days. Get your carbs from fruits and vegetables, typically about 50 grams per day.
• Low-carb days. These days are high in protein and fat, with most of your carbs coming from vegetables and small amounts of fruits. Around workouts, take in fast-digesting carbs to help replenish glycogen. Total carb intake is about 100 grams per day.
• High-carb days. On these days you consume 400–800 grams of carbs. “The purpose is to replenish your body’s glycogen stores, stimulate an anabolic response through insulin release and allow for some relief from all the restriction,” Mike says.
Follow the five-day rotation in “Cycling Your Carbs” when you want to try a carb-rotation program.
FAQ: When should I implement a high-carb day?
If you’re following a traditional low-to-moderate carb program to reduce bodyfat, you can benefit from a high-carb day without the complexity of the more restrictive carb-rotation plan. On an average day, you should consume 1–1.25 grams of carbs per pound of bodyweight, or 180–225 grams for a 180-pounder. Then, during one meal a week, boost your carbs significantly for one meal only. Take in as many carbs as you want or can, 250–400 grams worth, emphasizing starches and fast-digesting sources such as sugar. At this meal, try to keep fat intake in check to get a greater insulin response.
At other times during the week, consume more dietary fats in an effort to keep carbs and your insulin response in check. “For some reason, many people are consumed with the notion that dietary fat is evil,” Mike says. “But I don’t think it’s wise to consume low amounts of dietary fats.” Recent research bears this out. Diets with 15% or fewer calories from fats are known to decrease testosterone production, which can affect metabolism and muscle development. “Low-fat diets may also impair the absorption of fat-soluble vitamins,” Mike adds. He recommends consuming 30%–35% of calories from dietary fats on a typical day. This includes saturated fats, in about a 1:1 ratio with healthy fats.
FAQ: Is dietary fiber important to a bodybuilder since it can slow digestion and make you feel full when you’re trying to get in a lot of calories and meals?
It’s surprising how many bodybuilders overlook the dietary impact of fiber. Avoid fiber before and after workouts, but consume it at other times of day in larger quantities than bodybuilders typically do. “Fiber is incredibly important, and often underrated and undervalued by most Americans,” Mike says. Fiber holds considerable water and provides bulk to food residues in the GI tract. It exerts a “scraping” action on the cells of the gut wall, enhancing your ability to absorb nutrients. Fiber also binds to and dilutes harmful chemicals, inhibiting their activity and preventing them from entering your body.
“Many people, even strength athletes, are deficient in fiber,” Mike warns. He suggests that adult men consume about 40 grams of fiber daily, and 25 grams for women. “It’s very obvious, based on how people look these days, that most don’t even get close to this,” he says. His recommendation is based on an average diet of 2,000–2,500 calories per day. Bodybuilders consuming 3,000 or more calories daily should consume about 60 grams of fiber. Good sources include whole grains and whole-grain products, fruits, vegetables, seeds, nuts, beans and legumes.
Diet Sweeteners vs. Sugar
Are these no-calorie sweeteners a good carb substitute when trying to reduce bodyfat?
“This is a complicated issue,” says Jonathan Mike, PhD(c), CSCS, NSCA-CPT, USAW. “Sugar substitutes duplicate the effect of sugar in taste, but they usually have little or no food energy.” Some are natural and some are artificial, and they’re up to 200 times sweeter than sugar. Obviously, the biggest benefit in using sugar substitutes is that they help significantly reduce calorie and carbohydrate intake.
However, there is a downside. “I’ve some seen some research showing that, rather than promoting weight loss, the use of diet drinks is a marker for increasing weight gain and obesity,” Mike says. Study participants who consumed diet soda were more likely to gain weight than those who drank naturally sweetened soda. While this study used non-athletes, it’s possible that bodybuilders may see less desirable results when they use diet sweeteners compared to not using them at all.
“Interestingly, a sweet taste induces an insulin response, which causes blood sugar to be stored in tissues,” Mike says. “Because blood glucose doesn’t increase with artificial sweeteners, this may cause hypoglycemia [low blood sugar] and increased food intake.” In other words, we continue to crave sweets, consuming food until the craving is met.
Bottom line: If you use sugar substitutes while cutting carbs, make sure to ingest them with other foods to help mitigate cravings.