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A Guide to Carb Cycling and How it Can Impact Your Fitness

Counting the number of calories you eat in a day is no longer effective for improving your fitness potential.

Eating healthy is often a more involved process than simply tallying the number of calories you eat in a day. There are also the actual nutrients in those calories that need to be considered, like your protein, fat, and, most infamously, carbohydrates. Low-carb dieting is highly popular for weight management, but many people find that it’s too restrictive to be a realistic, long-term solution. Enter: carb cycling.

Here’s everything you need to know about carb cycling and how it can help you achieve your fitness goals.

What is Macro Counting?

“Macro counting” is an eating strategy in which you keep track of the number of grams of each macronutrient you eat per day. Macronutrients (carbohydrates, proteins, and fats) are all metabolized differently in your body. As such, each macronutrient also has a different calorie value per gram.

  • Carbohydrates: 4 calories/gram

  • Proteins: 4 calories/gram

  • Fats: 9 calories/gram

The three major macronutrients and their equivalent calories per gram.

Not all calories are created equally, and several studies show that the macronutrient contents of your diet can alter your end results. Macro counting addresses the importance of understanding how food affects your body beyond simple calories in/calories out approach. While counting your macros tends to be more involved than simply adding up your total calories for the day, this method can give you better insights into how the food you eat is affecting your workouts and your body composition.

One of the most popular examples of a macro counting diet is IIFYM, aka the “If It Fits Your Macros” diet. This type of eating pattern generally allows for more flexibility in your daily eating plan, rather than strict restriction and elimination that go hand-in-hand with more regimented diets.

What is Carb Cycling?

Carbohydrates have historically been villainized as the culprits behind unwanted weight gain and fitness plateaus. However, the relationship between carbs and your fitness is a little more nuanced than that. Carbohydrates are your body’s main energy source so your body needs a certain amount of carbohydrates that it can use to fuel your daily activities. While weight loss is a benefit of low-carb diets, like the Keto Diet, they’ve also been linked to some concerning side effects like nausea, fatigue, dehydration, and limited exercise capacity.

This is where carb cycling comes in. This more advanced eating pattern has traditionally been used by athletes to optimize their athletic performance, and now it’s also being used as a method for weight loss.

Rather than slashing your carbohydrate intake to a minimum, as you would with a traditional low-carb diet, carb cycling involves switching off between lower-carb intake days and moderate-carb intake days. Carb cycling can look different for everyone, but the most popular option is to save your higher-carb days for the days that you are going to be participating in higher-intensity workouts. This way, you can make sure that you’re giving your body enough carbohydrates to fuel you through your most active days.

How Carb Cycling Affects Your Body Composition

So why try carb cycling in the first place? One major reason lies in its potential to help you build muscle while losing fat.

Low-carb diets are a successful method for weight loss (at least in the short term) for a couple of different reasons, including their potential to help improve insulin sensitivity, lower your calorie intake, and put you into a state of ketosis, or “fat burn.”

But low-carbohydrate diets can also lead to a loss of muscle mass during intense exercise. When you eat carbohydrates, they’re broken down into glucose, which then circulates through your bloodstream (aka “blood sugar”) to be used for quick energy. And, they can also be stored in your muscles and liver in another form called glycogen. But when you’re eating a limited amount of carbs, you have much less circulating glucose that can be used for energy to complete a high-intensity workout. Instead, your body has to use your stored glycogen for energy, depleting your muscles in the process.

By cycling your carb intake, you can prevent this muscle degradation by refueling your muscle glycogen stores with an adequate amount of carbohydrates on those extra-active days.

It’s also interesting to note how low-carb diets can impact some of the hormones that influence your weight management behaviors. Take leptin, a hormone that regulates your energy and hunger cues. There’s evidence that eating a low-carb diet is linked to lower leptin levels, which can notify your body that it needs to eat more, throwing a wrench into your otherwise carefully-planned diet. For many people, this means that they need to experiment with different amounts of carbohydrates to find the intake that will best support their fitness goals. Because of this, carb cycling can be a potential solution for many.

Is Carb Cycling Good for Your Fitness Goals?

Carbs provide quick, easy-to-use fuel when you need it most. So a downside to low-carb diets is they are not very well-suited for people who work out. However, with carb cycling, you can use higher-carbohydrate days to give your body enough fuel to finish those longer, harder workouts that might be more difficult to complete when you’re taking in fewer carbohydrates.

Carb cycling could also be a useful tool for weight loss simply because of the low-carb element. Low-carb diets are proven to help you lose fat, making them similar to other calorie-restricted approaches. But, because carb cycling allows you to eat some carbohydrates when factored wisely into your eating plan, it could be a more sustainable approach. By carb cycling, you can approach nutrition from a more sustainable angle, and you won’t have to be as restrictive. Successful diets are the ones that you can follow for the long run, so carb cycling could be a viable option for anyone who wants to take advantage of better insulin sensitivity without eliminating carbs completely.

Are There Any Downsides to Carb Cycling?

Carb cycling could be an effective way to help you reach your fitness goals, especially when compared to stricter diets that do away with many carbohydrates. But on the flip side, this method is more complicated and involved than simply adding up the number of calories you ate in a day. It requires thorough planning to ensure that you’re meeting the correct amount of carbohydrates (in grams) for your body while ensuring your exercise plan is working with your nutrition to get you the results you desire. This type of eating plan could feel overwhelming if you’re looking for a simpler way to monitor your food intake.

Another thing to consider is carb cycling can come with some unpleasant side effects on low-carb days like fatigue, sleep problems, gastrointestinal distress, and mood issues. Carb cycling is not suitable for just anyone, either. Women who are pregnant or breastfeeding should avoid it, as should anyone who is underweight, managing an eating disorder, or dealing with any adrenal issues.

People with diabetes should also consult with their doctor before determining if carb cycling could be a fit for their lifestyles. Evidence for its use among those with diabetes is somewhat conflicting, though. While low-carb diets seem to be helpful for managing blood sugar, some experts believe people with diabetes and hypoglycemia should not try carb cycling.

Also, there is very little evidence as of now to suggest how well carb cycling actually works. More evidence-based research is needed to determine the effects of carb cycling on your health and fitness goals.

How to Start Carb Cycling

Familiarize Yourself With Different Kinds of Carbs

If you’re going to start watching your carb intake, it pays to understand the difference between simple and complex carbohydrates.

Your body can break down and absorb simple carbohydrates very quickly, so they can cause rapid spikes in blood sugar. Simple carbohydrates also tend to be processed more heavily than complex carbohydrates, which can strip them of other healthy nutrients like fiber, vitamins, and minerals. Therefore, having too many simple carbohydrates in your diet can increase your susceptibility to conditions like weight gain, heart disease, and Type 2 diabetes.

On the other hand, complex carbohydrates contain healthy fiber, vitamins, and minerals. They take longer for your body to break down and absorb, and they won’t trigger massive blood sugar fluctuations in the same ways that simple carbs will.

When it comes to carb cycling, it’s usually better to stick to more complex carbohydrates, both on low-carb and more moderate-carb days, to ensure you’re getting enough nutrients. Some examples of healthy complex carbohydrates you might want to add to your carb cycling rotation include:

  • Beans

  • Legumes

  • Whole grains

  • Vegetables

  • Fruits

  • Nuts

  • Seeds

It’s also important to note that these recommendations are general and not all-encompassing. It’s always a good idea to speak with a registered dietitian or certified nutritionist to better understand your individual needs.

Experiment With What Works Best for You

There is no hard-and-fast definition of carb cycling, which means that what works best for you may not work for someone else Generally speaking, a typical low-carb day might mean restricting your carb intake to roughly 20-57 grams of carbohydrates (about one cup of brown rice). In contrast, a more moderate-carbohydrate day might see about 225-325 grams per day based on a 2,000 calorie diet. But again, this can vary.

The frequency of low-carb to moderate-carb days also matters. Many people who carb cycle schedule their moderate carbohydrate days on the days when they are exercising intensely. But there isn’t currently enough research to suggest that there’s an “optimum” number of days per week that one should eat low-carb versus higher-carb.

Ultimately, your macronutrient needs can vary widely based on the number of calories you eat per day, the frequency and intensity at which you exercise, and your current health status. You might need to do some experimentation to find the right cycle that fits your goals.

Use a Nutrition Tracker

One of the biggest considerations to keep in mind before you start carb cycling is the amount of math it can involve. Not only do you have to determine how many carbohydrates, proteins, and fats are in each food you eat during the day, but you also need to tailor your meal plan according to whether you’re following a high-carb or low-carb meal plan for that particular day.

So nutrition trackers can be invaluable tools for anyone interested in carb cycling. . Plugging your daily food intake into a smartphone app reduces the amount of math you need to do and simplifies macro counting while ensuring you are eating the right number of calories for weight loss, maintenance, or gain (depending on your goals). Popular apps include:

  • MyFitnessPal

  • MyPlate

  • My Macros+

Track Your Measurements and Body Composition in Addition to Weight

Because carb cycling seems to affect your body composition and weight in various ways, it’s important to track more than just your weight to get an accurate picture of your progress.

To better understand how carb cycling is affecting your body fat versus your muscle mass, take regular measurements. Start by measuring your biceps, waist, abdomen, hips, and chest to use as a baseline for tracking healthy progress. You might also be able to track changes to body composition outputs like Body Fat Percentage, Skeletal Muscle Mass, Lean Muscle Mass, and Body Fat Mass—all of which can more accurately show you how your diet is changing your body more than a single number on the scale.

On a related note, it’s important to understand that changes to your body composition and weight can also lead to changes in your energy requirements. To avoid plateaus during your fitness journey, reevaluate your macronutrient intake every 8-12 weeks, as instructed by your dietitian, especially if you start to notice stagnation in your progress.


Carb cycling has been used as an energy optimization strategy by endurance athletes for years. But more and more people have recently begun to use this advanced strategy to take advantage of the fat-burning benefits of low-carb diets without burning out too quickly. It’s a fairly complicated diet that requires more research to understand its long-term effects, but it seems to be a promising method for weight management. Before you hop onto the carb cycling bandwagon, take some time to educate yourself on the types of carbohydrates and their individual benefits, and be sure to speak with a professional to ensure you can fuel your body properly using this method.

**Thank you very much InBody USA for your contribution and publishing of this article. For more visit

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