Everything You Need to Know About Carb Cycling

Macronutrients can at times be an overwhelming concept. How much of which do you need to eat and how many of them - for how long? If we think about it in a simplified scope, it can help. First, we remove protein, then we can look at just carbs and fats. And, we see the gas and oil you put in your car. In this metaphor fats are the oil and carbs are the gas. We now see that fats are always working and carbs are something we have to refeed on a more regular basis to keep the motor humming. With that understood we now need to figure the best way to carb feed to optimize how we use them.

What we are really looking at is carb cycling. We will break down larger time frame and smaller time frame (single day) cycling. Before we do that we need to dive into why you would want to in the first place.

A little background on energy dynamics and the roles of fat and carbohydrate will tell us why carbs are the nutrient we choose to cycle. Energy is constantly being used in the body for numerous active processes (requires energy). And while there are passive processes (does not require energy) our bodies have to meet the energy requirement of the active ones because all processes together ensure we do things like breath and have a heartbeat.

Fat and carbohydrate live in give and take, where the more you use fat (or carb) as a fuel the less you use the other (1, 2). The most influential variable on how much of each you use is the intensity of the activity. If you are sitting in your chair writing an article then you are using mostly fat and only small traces of carbohydrate. But, if you are doing deadlifts in sets of 6 then you are using mostly carbohydrate and only traces of fat.

Carbs are used in more intense and fats in less intense activities (3). That said, carbs are mainly there to fuel the exercise you do. It is not as simple as just that but this gives us a very easy way to look at the reason for being able to cycle carbs based on that day’s training requirements.

We now need to add one more layer to really understand why fat stays constant. While carbs and fats major roles are in providing the materials to create biological energy, they do play other roles. Fat plays a more significant role than carbs. One of the arguments behind the ketogenic and other low-carbohydrate dietary models is that carbohydrates are not an essential nutrient but fat is (4). When a nutrient is labeled essential it means that the human body needs it to live because it can’t make it. All this to say you “need” fat but you do not “need” carbs. This due to the roles they play outside of energy. While carbohydrate foods can provide many other essential nutrients the only thing the carb content of the food does is give the body the ability to make energy. But, fat plays roles like hormone, immune, and cellular membrane support. This is why fat intake must stay constant and carbs can be cycled.

This gives us the basis for why we can cycle in a smaller widow, like one day. So, lets look at that and see how you might implement it for yourself. First, we need to establish the need to focus on quality training. Training leads to the outcomes you design it to but only if you put in hard and meaningful work. These outcomes can and will be met if you apply this to all training sessions. Think about it like addition, 1 + 1= 2, you will always get 2 if you continue to put 1 and 1 together. But, if you fail to add what you need then your results will suffer. You accomplish good training addition by adding quality training sessions together. Part of that process is fueling the training and its recovery. Under that umbrella is carb cycling.

Lets say today is a training day and you want to plan your meals so that your training addition is optimized. The first thing you will do before this is figure out how many calories you need in a day. Many apps like Underarmour’s MyFitnessPal provide you with a good daily energy starting point. Once you have that you will create meals that satisfy the daily need broken up in even or almost even distributions of carbs, fats, and proteins. This is the easiest way to do it. But, once you bring carb cycling in you will need to change the distributions based on your training. All this means is creating higher and lower carbohydrate meals that altogether still meet the daily total of carbohydrates.

Implementing single day carbohydrate cycling comes down to moving carbs around the timing of your training. Hours before your training you want a lot of carbohydrates but you also want time to digest them. Just before your training you want a small amount and it is best for this to come in simple carbs that are in an easy to digest form (fluid). After training you want a lot of carbohydrates in a mix of simple and complex. Times that are further away from training you want a moderate amount. These amount designations are relative to your total daily carb intake goal, however the just before training carbs should not exceed 30-50 grams, depending on your body size and stomach sensitivity.

These recommendations allow for you to feed your training with energy as well as fuel recovery. The recovery process requires energy just as training does. It may not be as acutely taxing to the energy systems but once you train the body needs to repair and replenish via active and passive processes. You also have to remember that total calories are a significant part of recovering from your training and your daily carbs are included in that. This technique simply moves those carbs around to better time when you get calories.

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Short and long-term cycling have a lot in common as far as moving the most flexible macronutrient around to optimize the outcome. Long term cycling is anything a week and longer. It can be done for body composition, performance, or a combination or those. We’ll first break down body composition. The most prominent body composition aim is losing weight. In terms of structuring a healthier and more appropriate goal we will look at loosing fat instead. With that said the first thing to do is get your daily caloric requirement set, and after that you determine the macronutrient distributions. If you are using an app it will likely give you recommendations based on the questions you answered and the app’s algorithm. You now have your macros and can build in carb cycling to your training and nutrition plan to aid in body fat loss.

The main carry over from short-term to long-term cycling is that your are increasing or decreasing your carb intake based on the day of the week instead the proximity to your training. So, instead of daily carbs you look at weekly carbs. If you have 250g of carbohydrate a day then you have 1750g of carbs in a 7-day week. Simply, you will increase your carbs on training days and decrease your carbs on non-training days. As long as the weekly carb goal is met. In this fat loss model you are in a deficit. In order to try and get better training during this caloric deficit we increase the carb intake on training days by taking them away from non-training days.

With seven days and even distributions you get about 15% of your carbs each day. In weekly cycling you will change the percent based on the amount of training days. If you have five training days it is best to move to 20% on your training days and 10% on non-training days. The percent difference will depend on the amount of training days, but it is best not to starve yourself of carbs on non-training days.

If breaking the numbers into percents is not something that interests you go off of absolute values. Let’s say we are still using the 1750g per week. You can look at the original 250g per day and move 25-50g of carbs to your training days so its 275-300g on training days and 200-225g on non-training days. In a deficit you do not want to move too many carbs around as you do not want to starve yourself anymore than you have to on your non-training days. Although, there is leeway in this, the only semi-concrete number is the weekly carb goal. As long as you are giving yourself more carbs on training days, less on non-training days, and meeting the weekly carb goal within 20g then carb cycling can be a very useful technique for losing fat.

This type of long-term cycling can also be used to supplement weight gain or maintenance with a focus on quality training. In either case you determine the total calories and total carbs. After you have that you can look at your training. No matter how many training days you have you can use the following construct: increase the carb content of the meals before and after your training. Let’s say you train in the morning on Monday, Wednesday, and Friday. In this example you would add carbs to the dinner the night before the morning workout and the meal that you have after it. To ensure balance you would remove carbs from your non training days by taking the same amount from each meal.

In this three-day training week example you would remove 20% of your carbs across the non-training days and add those to your dinner and post workout meals. Twenty percent is a good starting point for a carb cycle structure in this manner, however like all things in training and nutrition there needs to be observation of results and adjustment as necessary. Once you find the right amount to pull from your non-training days you can use this to aid your fueling and recovering.

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The last use of carb cycling is related to event performance. In this context we still need a daily carbohydrate goal to then spread across the days. We use that goal to set our maintenance carb intake. Once we have this and the timeline to the event we can start to taper carbs in. It should be noted that in this type cycling other macros will be replaced with carbohydrate due to the priority energy is taking over other concerns.

The nature of event will determine how carbs are manipulated and at what amounts. The minimum amount of time you want to start to cycle up on carbs is 5 days out. This is because you do not want to shock your stomach and gastrointestinal tract with a huge influx of carbs and sugars. The majority of carbs in this type of cycle should come from simple and easy to digest sources as to not overfeed on fiber. This ensures absorption and utilization of the carbs can take place without causing gastric issues. That said, you will increase carb intake in even increments across the days leading up to the event.

If you have six days and you are going to increase a total of 200g over those days you add 40g per day so that on the day before the event you are eating your normal maintenance carbs plus 200g. You always want to reach the carb load goal the day before the event to ensure your body is loaded and you are able to use the carbs you are giving it. The further you start away from the event the better. Think about it in a slow and progressive manner, the slower you increase the intake the more effective the load will be, however there is such thing as starting too far out. You want to start far enough out so you increase your body’s ability to store carbohydrate in the muscle but not so far out that you are creating an unnecessary surplus. This could lead to unwanted weight gain. The best time to start a carbohydrate load is 6-8 days before the event.

When implementing a carb load for a single event you will add in carbs evenly across the days. The first day of the load starts by decreasing fat intake to 10% below maintenance and increasing carbs to match the lost fat calories. After the first day you will leave fat alone and decrease protein at the same rate you are increasing carbs until protein reaches a preset minimum. This minimum is set at half a gram per pound of body weight. Once you reach that minimum you will stop decreasing protein but still increase carbs as planned. With this, it may be necessary to go into a surplus.

You do all of this to prioritize carbohydrate and energy storage. While this is one way to execute a carb load there are other variations based on your needs. These variations can include setting predetermined minimums for both fat and protein that allow for the best macronutrient distribution. This could come in a variation of ways but is ultimately designed to feed the athlete so that there is minimal disruption of digestion and maximal energy utilization.

Once the event is completed you will need to return to maintenance calories in the same fashion you loaded. This means slowly reducing carbs back to its maintenance amount over the days following the event. However, the day after the event you will not change carbohydrate or fat intake as you will want to fuel recovery of the competition. Although on this day you will increase protein to 25% above maintenance. You do this to aid in the recovery process. The second day after the event you will increase fat back to maintenance and decrease carbs to match the fat calories that you add back in. On the third day decrease protein to maintenance and begin decreasing carbs in the same incremental fashion you loaded them in. You will you do this until you reach maintenance carbs and calories.

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These may sound like complicated and rigorous things to do, but if you take a step back and look at it you see we are talking about food. So, depending on the type of cycling you will add more rice or pasta or sweet potato (or your choice) to your meals and remove those from others. In some cases you will add in sugary drinks or snacks. Really what you are doing is increasing or decreasing the carbs you consume at a meal based on its proximity to a training session. If you are not ready to get down to using percent or even absolute measurements all you have to do is increase/decrease carb content of a meal while still meeting your daily need.

The carbohydrate loads discussed here can be very useful for someone competing, trying to lose/gain weight, or optimize training outcomes; but in order for these to work you must know that you are working with your stomach and intestines. You know your body and how it responds to different foods better than anyone. Care must be taken when changing how you feed yourself. One of the most detrimental things to training can be how your body is reacting to what you are feeding it.

Take-aways for short-term/single day carb loading:

1. Determine daily calorie and carbohydrate needs. Based on training for that day manipulate carb allotted per meal relative to total daily need.

2. Two to four hours before your training you eat a lot of carbohydrates from mostly simple sources.

3. Thirty minutes to one hour before your training eat a small amount (30-50g) of simple carbs from an easy to digest form (fluid).

4. After training eat a lot of carbohydrates from both simple and complex sources.

Take-aways for long-term carb loading:

1. Determine daily carbohydrate needs and multiply by seven to get weekly carbohydrate needs.

2. Distribute carbohydrates across days so that training days have more and non-training days have less.

3. Depending on your weekly total carbohydrate intake take 25-50g from non-training days and add to training days.

4. To get more specific with this technique follow these recommendations:

a. Increase carbohydrate content of meals before and after training sessions

b. Hit weekly carb goals by removing carbs from meals not before and after sessions

c. Do not remove more than 20% of carbohydrates from these meals

Take-aways for single event carb loading:

1. Start 6-8 days before the event.

2. Determine daily calorie and macronutrient needs (this provides maintenance macros and calories).

3. Determine amount of carbs you need to load (dependent on event).

4. On the first day of the carb load decrease fat intake to 10% below maintenance and increase carbohydrate intake to equal the loss in fat calories.

5. From the second day on increase carbs equally across days to peak carbs the day before the event.

6. decrease protein equal to increase in carbs until preset protein minimum is met (half a gram per pound of body weight).

7. The day after the event increase protein to 25% above maintenance and leave fat and carbohydrate alone.

8. The second day after the event bring fat back to maintenance and bring carbs down to equal the increased fat calories.

9. On the third day after the event bring protein down to maintenance.

a. Begin the carbohydrate taper on the third day. Taper carbs out in the same incremental fashion you tapered them in.

References

1. Brooks, G. A. and J. Mercier (1994). "Balance of carbohydrate and lipid utilization during exercise: the "crossover" concept." J Appl Physiol (1985) 76(6): 2253-2261.

2. van Loon, L. J., et al. (2001). The effects of increasing exercise intensity on muscle fuel utilisation in humans. The Journal of physiology, 536(Pt 1), 295–304.

3. Coyle, E. F., (1995). Substrate utilization during exercise in active people. The American Journal of Clinical Nutrition, Volume 61, Issue 4, Pages 968S–979S.

4. Das U. N. (2006). Essential fatty acids: biochemistry, physiology and pathology. Biotechnology journal, 1(4), 420–439.

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Need help with your nutrition? This article was authored by MPS Coach Joe. Contact him.

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