How Carbohydrates Work and Why You Need Them

How Carbohydrates Work and Why You Need Them

Carbohydrates have got a bad reputation. They are accused of (literally) weighing you down from reaching your fitness goals. What do they do? Are they harmful? Do you need them? How do they work with your muscle growth?

These are the questions we’re going to answer as we dig into this misunderstood macronutrient.

What Are Carbohydrates?

Carbohydrates are an important source of nutrition and energy (calories), just like Protein and Fats. More importantly, carbs are your body’s primary source of energy. That means energy for you to push harder during your workouts and to keep your engines burning while your body gets to work repairing and building muscle.

So, how does this work?

Your body breaks down carbs into glucose (or sugar) for fuel. Glucose that isn’t immediately used is first stored as Glycogen in your liver and skeletal muscles, to draw from when you need it.

Part of the fear of Carbs is that they make you gain weight. It is true that if you eat too many carbs without burning the energy, your body will start storing it as fat. But we want you to put that fear aside for a moment because carbs are not the enemy - it’s the food choices we make that throw our Carb to Protein and Fat ratio out of balance.

Too many carbs and your body will stop storing it as glycogen and start storing it as fat.

If your goal is to build muscle, you should try to include 30-40% carbohydrates as part of your diet.  Any fewer carbs and your body will resort to muscle catabolism to get the energy it needs.

This assumes a normal training regime of 3-4 times a week in the gym with weights and high-intensity cardio. For every hour extra you train, try to include an extra 50-100 grams of carbs for ideal energy consumption.

Bodybuilders and extreme weight lifters increase their carbohydrate ratio to 50-55% of their daily intake in order to fuel multiple workout sessions at a higher intensity than normal training.

Graphic of Macronutrient Ratios by Fitness Goal

The Myths

Because there are so many anti-carbohydrate diets out there (Ketogenic, Paleo, and Atkins just to name a few), we need to briefly touch on some of the myths that you may have heard.

“Carbs make you gain weight”
Mostly False. While carbohydrates can be stored as fat if you aren’t burning them, that doesn’t mean they make you gain weight  This myth mainly comes from the rapid weight-loss that people experience on these restrictive carb diets. This rapid weight loss doesn’t last and that lack of macronutrient causes the body to break down protein in the muscles for energy. But as we’ll explain in a minute, your body needs carbohydrates for fuel to burn.
“All carbs are equal”
False. You can choose to eat carbs that provide a range of benefits like feeling fuller, longer, more fiber content, and slower digestion. Or you can choose carbs that have little to no nutritional value, leaving you hungrier faster, and possibly storing the excess sugars in fat. We’ll explain the different sources for carbs in the next section
“Bread is bad”
Look at a croissant. How can this perfect food ever be called bad? It’s just so good. Seriously though, not all bread is bad. The key difference between good and bad bread choices are whole grains. The whole grains found in bread are an excellent source of complex carbohydrates. Stay away from processed or refined  grains which have added sugars and don’t have the fibre your body needs for good digestion.

How Carbs Work For Your Body  

Female body builder holding ropes with flexed biceps

While some refer to carbs as “good” or “bad”, they are better understood as complex carbs and simple carbs.

Simple Carbohydrates

Simple carbs contain just one or two types of sugars, which means you metabolize the carbs into sugar very quickly. The sugar is stored in your blood to be used for energy. If you eat a lot of simple carbs, or eat them at the wrong times, you will end up storing the excess sugar in fat cells, which is how carbs can lead to weight gain

Simple carbs are found in lollies, sugary drinks, and anything packaged, processed or refined. Aside from dairy products or honey, simple carbs are not naturally found in most foods.

This makes it really easy to spot simple carbs - if it’s not a natural food source, it’s a simple carb. They should be avoided or limited as much as possible in your diet since they are of little nutritional value. It can be as simple as shopping for food only around the perimeter of your supermarket where the fresh foods are kept.

An exception would be for body builders who want to have an immediate spike in glycogen levels during training. In this case, an athlete is using the simple sugar as a boost of energy for the workout and knows the sugars will be used as energy before they are stored in fat.

Complex Carbohydrates

Complex carbs contain at least 3 or more sugars, and a whole host of essential nutrients your body needs. Because of this, your body processes the carbs at a slower rate. You feel fuller longer and don’t see the highs and crashes in energy levels you’d find in simple carb sources.

Complex carbs come from fibrous and starchy foods.


Fibre is the indigestible ingredient in complex carbs. You need fibre for healthy digestion and to feed the good bacteria in your intestines. Because it’s not broken down in the stomach, it travels through your intestines, converting into essential fatty acids, carbon dioxide, and hydrogen.

You need 14 grams of fibre per 1000 calories you consume.  

Sources of good fibrous complex carbs include

  • Fruit
  • Leafy vegetables (Kale, Lettuce, Celery)
  • Nuts (Almonds, Cashews, Walnuts)
  • Beans (Red, Kidney, Chickpeas...etc)
  • Whole Grains (Whole Wheat, Oats, Brown Rice, Quinoa)

Starch is the other half of complex carbs. Starches take several steps to digest fully, making it a healthy carbohydrate source. It’s broken down into glucose like every carb, but the process is slower, making you feel fuller having consumed it.

Good sources of starchy carbohydrates include:

  • Potatoes
  • Corn
  • Peas
  • Squashes and Pumpkins
  • Rice

How To Eat Carbs

Now that you have an idea of what carbs are and how they are broken down your body, let’s identify how to eat them for maximum effect in and out of the gym. If you’re getting the right ratio of macronutrients for your body type, you’re on the right track.

Timing Your Carb Intake

You want to time your carbohydrate intake for two reasons.

First, you want to eat carbs at the right time so your body doesn’t store it as fat. If your body is immediately burning off that glucose as energy for your training, then you won’t store it as fat. You body is very good at storing the excess carbs you aren’t using, so don’t give it that chance.

The second reason you want to time your carbs is to give your body enough energy. If your training session is includes intensity (as it should), you’re going to be depleting your glycogen stores. If you don’t have enough energy in the glycogen stores in your liver and muscles, you’re going to experience fatigue and a lack of performance.

Eating your carbs at the right time ensures you have a constant supply of energy to maximize your workouts and gives you enough energy to perform your best every time. Even if you’re cutting calories to lose fat, you’ll still have the energy you need to plow through your workouts.

Bonus: Eat your carbs with protein. Protein slows down your digestion and also makes you feel fuller.

Best Times To Eat Carbs

First Thing in the Morning

Regardless of it is a training day or not, find a good source of carbohydrates in the morning. Your body has depleted glycogen levels after the night’s sleep, so you need to replenish that energy to be ready for your day.

Try a bowl of muesli. Make yourself a portion of steel-cut oats topped with berries. Have an apple to start your day with a fibre source. That first hit of carbs in the morning is crucial after 8 hours of no food or energy.  

Pre Workout

On a training day, you want to plan to hit your body with a good quantity of carbs in preparation for the session. At least an hour before (so you aren’t training on an empty stomach), consume a good source of carbohydrates. Your training session will prompt your body to immediately convert those carbs into fuel for the workout and not to store it as fat.

Try eating a bowl of quinoa or have some rice with wild-caught salmon for your protein source.

Post Workout

After your workout, you should have completely depleted your glycogen stores. You should feel like you have nothing left and so now is a good time to have another intake of carbohydrates. The reason is quite similar to eating your carbs in the morning. Your glucose levels need to be boosted so your body has the energy it needs to replenish those glycogen stores.

Another reason for the post-workout carb intake is to increase your insulin levels. When your body breaks down the carbs into sugars to use for energy, it is absorbed into the blood with insulin. That insulin helps your muscle tissue absorb protein as well, boosting your muscle gains after the workout is complete.

Eat a starchy complex carb like rice or potatoes with a protein source like chicken breast, or oats with fruit.

The Carbohydrate Wrap-Up

Carbs are an important part of your diet and, with an active lifestyle, do not hold up to the rumours floating around that say “Eating Carbs is making you fat!” - Your body needs this energy to help you train hard at the gym and to keep your body functioning properly.

Carbohydrates break down into sugars that your body uses for fuel. Eating the right types of carbs at the right times will help you maximise their effect and impact on your body.

Remember, simple carbs like White Rice, are simple because they are metabolised much faster into sugar. That’s not a bad thing if you are going to use that energy quickly, but for your daily nutrition it’s always a better idea to stick with complex carbs like Whole Grains - or Fibrous Vegetables!