What Are Carbohydrates?

Carbohydrates of some kind will form the bulk of the bodybuilder’s diet, in particular when adding mass or bulking. Even when cutting, the consumption of carbs, especially the type and timing, are still crucial to achieving your gym goals.

This article covers the basics of the different types and uses of carbohydrates, their relevance to the bodybuilder, and their use in achieving different goals – whether that is adding quality mass or reducing body fat.

Are carbohydrates good for you?

Carbs are good for you as they are the body’s main source of energy. They help fuel your brain, kidneys, heart muscles, and central nervous system.

Carbohydrates are also a major source of nutrients such as fibre, helping digestive health. Whole grain sources of carbs contain multiple vitamins and minerals including essential fatty acids, B vitamins, folate, vitamin E, zinc, and magnesium. Studies show that high fibre carbohydrates, like vegetables and legumes, improve metabolic health and lower the risk of multiple diseases.

There is also a misconception that carbs are innately bad for you and always make you gain weight. In fact, carbs are good for weight loss so long as they are not refined. Carb foods such as white rice and white bread do not have the same essential nutrients as whole grains like brown rice and brown bread, meaning they only contain fatty sugars that are counterproductive to weight loss. Consuming the right type of carbohydrates, such as wholegrain and vegetables, can help you to lose fat.

What do carbohydrates do?

Carbohydrates have a variety of functions in the body and can be used in several different ways to achieve your fitness goals. Carbohydrates are primarily a great source of energy but carbs are also used in bodybuilding to help shape your physique and fuel your training.

Energy Provision

Many people ask, “what are carbohydrates broken down into?”. Digestible carbohydrates, in whatever form, are ultimately broken down into their constituent monosaccharides and absorbed into the bloodstream via the liver. The monosaccharides may be converted to glucose and used immediately as an energy (ATP) source via glycolysis, the TCA cycle, and oxidative phosphorylation.

Alternatively, they will be stored (associated with water) as glycogen in both the liver and skeletal muscle. This energy store can be quickly mobilised to supply the muscles and the brain, which relies solely on glucose as its energy source.

The capacity for storing carbohydrates is limited when compared to the nearly limitless amounts of fat that can be stored in the body. Therefore, if excess carbohydrates are consumed beyond the body’s needs, they will be transformed and stored as adipose tissue.


Carbohydrates play a pivotal role in the bulking diet of any bodybuilder – particularly when bulking. Not only do carbs for bodybuilding add calories to ensure energy excess and provide valuable vitamins, minerals and fibre, they can also ensure that muscle recovery is swift and effective following training.

The bulking diet should be largely composed of low to moderate gestational index (GI) carbohydrates, to keep blood glucose and hence insulin levels largely stable. The best carbs for bodybuilding include wholemeal and brown bread, rice, pasta, sweet potato, and most fruit and vegetables. The pre-workout meal should contain sufficient amounts of low GI carbs to ensure the training is adequately fuelled.

Post-workout carbohydrate form and timing is subject to much debate. One argument is that, by consuming a high GI carbohydrate such as dextrose or maltodextrin with whey, immediately post-workout, insulin levels are spiked, thus promoting the storage of protein and carbohydrates. This maximises the recovery of carbohydrate stores and repair of muscle damage, ultimately leading to muscle growth.

However, there are many arguments against the need for this immediate supply of quick-acting carbohydrates. These suggest that equal, if not better, results can be gained by consuming a meal containing low to moderate GI carbohydrates.

For athletes training for fitness or endurance and not muscle gains, fast-acting carbohydrate, immediately post-training is of great importance.


On the other side of the coin, a low carb bodybuilding diet is perfect for cutting. The trend when attempting to lose body fat is to minimise the intake of carbohydrates. While reduced intakes are advisable for fat loss, elimination is not necessary, merely smaller portions of low GI carbs.

Pre- and post-workout carbs must be consumed in adequate quantities to fuel training and recovery or progress will be hindered. Again, low GI carbohydrates, in the post-workout meal are favourable to fast-acting ones.

Various diets focus on the timing and type of carbohydrates consumed. Timed ketogenic diets (TKD) will eliminate virtually all carbohydrates except for those consumed around training. This diet induces periods of ketosis, at which point fat stores are mobilised and used for energy, in the absence of carbohydrate stores and can contribute to fat loss.

Some people use a carb cycle for bodybuilding. Cycled ketogenic diets (CKD) are similar to TKDs but carbohydrate intake is cycled, always being high around workouts but also including days of higher carbohydrate intake overall, followed by subsequent low carb days and depletion training (high rep ranges) before the next higher carb day.

Ultimately, any cutting diet is arduous and challenging. The choice of diet will depend upon the individual, their goals, and their compliance.

Classifying Carbohydrates

What are complex carbohydrates? What are refined carbs? What are simple carbohydrates? In reality, these terms are not the only method for classifying carbs.

There are numerous ways to classify carbohydrates, depending on their structure or digestibility and absorption. Probably the most relevant for bodybuilders is the glycaemic index (GI). Whilst this is broadly similar to classifying carbohydrates as simple and complex, it is not an identical method.

The GI measures the reaction of the blood glucose levels to consuming carb-containing food when compared with pure glucose, which has a GI of 100. Low GI foods, below about 55 cause glucose levels in the blood to rise only slowly and over a long period, compared with high GI foods of over 70, which lead to a rapid but short-lived rise in blood glucose.

In practical terms, a low GI food with its more sustained release of glucose into the blood will keep you feeling full for longer compared with a high GI food that will satisfy hunger only for a short time. The situation is complicated by the fact that consuming different foods with one another will alter the GI. Thus, eating high GI white bread with butter will lower the overall blood glucose response, so lowering the glycaemic load. Fat and protein both act to slow the absorption of glucose from carb-containing foods, reducing the glycaemic load of the meal.

The most biologically relevant method of classifying carbohydrates is by the insulin index or II. This describes the response of blood insulin to consuming any food, not just one that contains carbohydrates. Some meats and other low carbohydrate foods evoke an insulin response without a glycaemic response. The insulin index may, therefore, be of most use for dietary management.

Types of carbohydrates

There are many different types of carbs. The main types of carbohydrates are simply referred to as sugar, starch, and fibre however it is important to understand the composition of these carbs to truly appreciate the benefits of each.


The simplest form of carbohydrate and the building blocks of more complex carbs, sugars are single or double units known as saccharides.

Monosaccharides, such as glucose, fructose, and galactose are single-unit sugars. Meanwhile, disaccharides, such as sucrose (two glucose molecules) and lactose (glucose and galactose), are made up of two monosaccharides that are joined together.


These molecules are made up of short chains of monosaccharides, typically between 3 to 20. They often pass through the small intestine into the colon, where they are digested by the so-called ‘friendly bacteria’, helping them to survive and multiply in the gut.

For this reason, some oligosaccharides, such as fructooligosaccharides (FOS), are known as prebiotics. As oligosaccharides taste slightly sweet but are not absorbed, they are used as bulking agents in low-calorie granulated sweeteners.


These large molecules are made up of many hundreds of monosaccharides, joined with different bonds creating unique structures. Glycogen is a storage carbohydrate composed of many glucose molecules and housed in the muscle and liver as an energy store, to be broken down when energy supplies are required. Starch is the plant equivalent of glycogen, acting as an energy store.

Dietary fibre

This is the indigestible part of carbohydrates, consisting of non-starch polysaccharides (NSP) and other molecules such as oligosaccharides, inulin, and pectin.

These molecules reach the colon relatively unchanged. Soluble forms of fibre may be used by the microflora in the colon for energy, helping to maintain adequate levels of “friendly bacteria”. These bacteria, when digesting the soluble fibre, produce by-products such as short-chain fatty acids, which are known to have considerable health benefits. The insoluble fibre acts to absorb water and produce healthy bowel movements by creating large, soft stools that pass through the system more rapidly.

What foods are carbs?

Carbohydrates can be found in a wide variety of different foods. From bread to bananas, a lot of your favourite foods contain carbohydrates. The key to bulking up safely is to select healthy foods that are high in carbs, rather than gorging on calorific junk food.

Examples of processed carbs to avoid include:

  • Sodas
  • Fries
  • White bread
  • White rice
  • Pasta

Foods that contain unprocessed carbs include fruits, vegetables, legumes, beans, and whole grains. Fruits such as blueberries and oranges are high in fibre, whilst veggies such as sweet potatoes and beetroots are a good source of starch.

Combine the following high carb foods into your diet:

  • Quinoa
  • Buckwheat
  • Oats
  • Grapefruit
  • Apples
  • Kidney beans
  • Chickpeas


Carbohydrates have many forms – from monosaccharide sugars to large complex starch and storage polysaccharides. Carbohydrates provide both an immediate source of energy for the brain and muscles and can also be stored as glycogen.

Carbohydrates provide the bedrock of bulking diets by adding calories, fibre, and micronutrients. However, to ensure that cutting is effective, you need to provide your body with adequate fuel for training and recovery.

Here at Performance Meals, we offer high protein, low carb meals that are perfect for cutting. Reducing carbs without completely eliminating them, our diet packages help you to increase your protein intake and improve portion control to get the trim physique you desire.

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