Carb Cycling Diet: What is Carb Cycling and When to Use It

Greater insulin sensitivity, more energy, improved mental clarity and brain health, and weight loss and management are among the reasons why celebrities, influencers, and even athletes like Tim Tebow are flocking to the ketogenic diet. 

Also Read: Tim Tebow: 6 Reasons to Take the KETO 30 Challenge

If that sounds like you, you may be interested in carb cycling. This combines the best of both worlds: the health benefits of a low-carb diet, along with the occasional surplus of carbs.

Surely you're wondering: 

Can having a carb refeed day once or twice a week help you lose more weight or enhance performance?

Let's look at what the science says, and how you might combine carbohydrate cycling with a low-carb diet like keto.

What is Carb Cycling?

Instead of following the same macronutrient split (a division of proteins, carbs, and fats), you follow one specific low-carb protocol for a set number of days, then intentionally deviate from that plan for a "refeed" day. 

Also Read: Keto Macros: How to Calculate Macros for Keto

On a refeed day, you would eat enough carbs to replenish your muscle's glycogen stores, which may offer performance, metabolic, and weight loss benefits (more on that below).

Examples of carb cycling structures you might use include:

• 3 on, 1 off: You follow a low-carb diet for three days, then refeed on day 4.
• 6 on, 1 off: You follow a low-carb diet for 6 days, then refeed or take the 7th day off.
• Training/rest days: You eat more carbs on days you exercise. On rest/recovery days, you eat very few carbs.
• Special athlete structures: An athlete might time their refeed days around competitions or special training events.

Who is Carb Cycling For?

Here are 3 reasons you might consider using a weekly or bi-weekly refeed day.

1. Performance Gains

But studies show that low-carb diets won't negatively impact your workouts, and can simultaneously improve health markers like fat loss [1].

But if you're doing a lot of aerobic exercises (moderate-intensity, steady-state workouts like running, biking, or swimming), you may find yourself feeling sluggish if you don’t replenish your glycogen stores. That's where carb cycling can be useful.

Eating carbs increases the amount of muscle glycogen you have available for exercise, and can be especially effective for long-distance events or intense weightlifting [2].

Some science also shows that eating carbs after working out (along with protein) can promote muscle growth [3].

So periodically giving your body carbs could, in theory, help increase your performance in the gym or on the road.

2. Metabolic Benefits

• Lower insulin levels (the hormone responsible for controlling blood sugar)
• Increase your metabolism so that you burn more calories at rest
• Produce more ketones, which have been shown to enhance cognitive performance.

3. Weight Loss

• Low-carb diets are more effective than high-fat diets for weight loss. Eating low-carb for three- or six-day spurts over time is likely going to help you reach your goals [5].
• One of the perceived drawbacks of a low-carb diet is the level of food restriction. Many people don't like that they can't eat carb-dense foods like bread, pasta, and rice. But with a refeed day, you don't have to completely eliminate these foods [6]. However,  many people find that substituting popular carb-heavy foods for keto-friendly alternatives will satisfy their cravings.

Of course, there are some downsides to carb cycling as well. 

Drawbacks of Carb Cycling

Which raises the question: What are the negative consequences of carb cycling?

Here are some potential drawbacks to consider:

• There isn't a ton of science about carb cycling. Much of the research points to established information regarding a low-carb diet, meaning some of the claims online are just speculation.
• Depending on the type of person you are, you might find carb cycling too complex. For example, if your schedule is busy, you might find it hard to stick to a plan of three days on, one day off. In this case, it might be easier to reach your goals using a plan that stays the same each day.
• While carb cycling is designed to allow for structured refeed days, it has a pretty rigid structure, which could increase the likelihood of an eating disorder [7].

Carb Cycling and the Ketogenic Diet

In ketosis, your liver produces ketones, which burn fat, not glucose, as your primary fuel source. You only get into ketosis by restricting carbs to around 5% of your daily caloric intake [8].

If you're thinking about combining carb cycling and keto, here are a few things to consider:

• If weight loss is your goal, eating lots of carbs every fourth or seventh day will take you out of ketosis completely. Depending on how many carbs you eat on your refeed days and how often you exercise, it could take several days before you get back into ketosis again. 
• If performance enhancement is your goal, many keto dieters rely on exogenous ketones instead of extra carbs for a boost before workouts. You might try BHB (Exogenous Ketones) instead of carb cycling.
• Instead of carb cycling, you can also time your carbs by eating the majority of them before and after you exercise. Eating about 30 grams of carbs before your workout will boost performance without taking you out of ketosis. 

Ketogenic Diet vs. Carb Cycling: What to Consider

As a tool, there's a lot to like about it—you can boost performance, enhance your metabolism, and lose weight without feeling like you're restricting your favorite foods all the time.

But most of the information online is speculation instead of backed by research and science. 

Those who combine keto and carb cycling may find it to be a little too restrictive or complex. Depending on your personality and schedule, it may or may not work for you.

At the end of the day, the results are going to come from consistency. Whatever your tool is, whether it's keto, carb cycling, or something else entirely, the key is to stick with it. That's how you'll lose weight or notice performance gains over time.