Carb Cycling is a more advanced version of Carb Timing: it is about matching the use of carbohydrates to the training days. What does the Carb Cycling nutrition method promise? Is Carb Cycling only for bodybuilders, or can it also be used for hobby athletes who go to the gym? These questions can only be answered individually because whether the Carb Cycling method makes sense for someone or not depends on various factors.
What is Carb Cycling?
The method is mainly established in bodybuilding because it is about adjusting the amounts of carbohydrates to the individual training days: On training days when large muscle groups or the basic exercises are trained (squats, bench presses, pull-ups, deadlifts), high carb is eaten: This means that carbohydrates are eaten at every meal (main meals and snacks). More on the exact macro distribution follows later in this article.
Medium carb days occur on training days – on which smaller muscle groups and more isolation exercises are trained (e.g. arm training biceps curls and triceps stretches). There, carbohydrates are eaten in more than half of all meals. Rest days are so-called low-carb days: Similar to the keto diet (only with more protein), almost no carbs are eaten.
There are different definitions of the carb cycling diet and small adjustments can be made depending on training phases, goals, and circumstances.
Carb cycling - what can this form of nutrition do for performance and sport?
As already mentioned, carb cycling is primarily known from bodybuilding. Doing high-carb days when training and low-carb days when less intense exercise takes place is basically very useful in many sports. One of the main advantages of carb cycling is that the metabolism is constantly stimulated. In addition, it is important to explain again in this context why the body needs few carbohydrates when there is little exercise:
You can think of it like an engine; if the engine is running little, it needs less fuel (=carbohydrates), if there is too much fuel, it has to be stored somewhere else. The body then converts the fuel (carbohydrates) into fats and stores them as reserves because nothing is dumped here. In addition, a strong engine requires a larger tank with more storage capacity because this engine consumes more fuel. You can strengthen the body's own engine and increase its storage with targeted muscle building because muscles have carbohydrate stores and these can be increased through training and the right supply of nutrients.
The less body fat you have and the more muscular your body is, the more efficiently the hormones work that are responsible for how well the engine runs. When this works optimally, the engine requires a lot of fuel (protein, carbohydrates, fat), which then works most efficiently with more carbohydrates. With more body fat and less muscle, the body cannot use the carbohydrates properly and stores them as fat as explained above.
The optimal carb cycling plan - here's what it looks like
The number of low-carb days and high-carb days depends on the current physical starting position (body fat and muscle mass), personal goals as well as the current training intensity, training volume and number of training days. Carb cycling is therefore somewhat more complex - after all, it is also a very advanced nutrition concept for targeted strength training.
The optimal carbohydrate intake per day can be calculated with a special calorie calculator. However, this is best done by an experienced coach, as body fat percentage and muscle mass should be considered. The approximate percentages for macronutrient distribution on low-carb days, high-carb days and, if applicable, medium carb days can be found in a section below.
The Carb Cycling macronutrient distribution
Basically, you eat low-carb on rest days, i.e., non-training days. On training days when smaller muscle groups or isolated exercises are trained, e.g., biceps curls, triceps stretches, flies, abdominal training, leg extensions or conditioning training, medium carb is recommended.
However, when global exercises are trained that involve large and multiple muscle groups at the same time, high carb is eaten. Examples of exercises on such days are squats, pull-ups, bench press and deadlifts. The macro distribution can vary depending on the starting position, goal, and training volume.
So, the following macro distribution is just an example of what the calorie distribution to the three macronutrients in Carb Cycling might look like for someone who has a low body fat percentage.
(As a man under 12% and as a woman under 16%) …and already has a base of muscle.
Low-carb day: 35% protein, 15% carbs, 50% fat
Medium-Carb Day: 30% protein, 40% carbs, 30% fat
High-Carb day: 30% protein, 55% carbs, 15% fat
It should also be considered that on low-carb days (where no training takes place) fewer calories should be consumed than on medium and high-carb days, as the demand for nutrients is somewhat lower. However, a higher protein consumption is important for optimal recovery.
Low-carb diet within the Carb Cycling? Here's how to start
With carb cycling, a healthy and routine diet should be developed in advance. As already mentioned, the method only makes sense if intensive sport is practised. It should also not be used if you have a lot of body fat around the middle of your body and suffer from cravings because in this case, it is relatively clear that the body cannot currently manage carbohydrates well and blood sugar is unstable. This means that hormones, predominantly insulin and cortisol, are not working optimally.
An awareness of calories and macronutrients as well as some experience with tracking calories is also a prerequisite for carb cycling.
For starters, you can only distinguish between low-carb and high-carb days; all training days are high-carb, all non-training days are low-carb. This allows you to approach the method in two steps.
Do I need a Carb Cycling Calculator?
There are various online calculators in which you can enter your personal values (age, height, workouts per week, body type and goal). The Carb Cycling Calculator then calculates the calories and macros you should eat on high-carb days, medium carb days and low-carb days. At first glance, such a calculator is a great thing because it seems to make a lot of work easier, but it usually only calculates on the basis of body weight relating to height and activity level.
The biggest problem here, especially for athletes, is that the body composition is not considered: Body fat percentage and absolute muscle mass play a very decisive role: whether a 1.90 m tall man weighing 95 kg has a body fat percentage of 30% (overweight) or 12% (muscular) makes a huge difference to how many calories he needs, and the goal is also decisive here.
Do women have to pay attention to special features when carb cycling?
Women should basically observe the same things as men when carb cycling. However, the hormone insulin works differently during the menstrual cycle and the blood sugar reacts differently to carbohydrates. Studies have shown that blood sugar spikes significantly more in the week before menstruation than in the week after. Accordingly, the extreme high-carb days could possibly have a negative effect on hormone balance.
The issue is very individual, but especially those who experience sugar cravings before and during their cycle should not eat numerous carbohydrates with a high glycaemic index, or more precisely high glycaemic load, especially then.
In addition, women who tend to produce more stress hormones may have trouble falling asleep in the evening without carbohydrates. If this is the case, the low-carb days should also be adjusted so that a little complex carbohydrate is eaten 2h before sleeping.
Carb cycling vs. keto diet
Carb cycling does incorporate some basic principles of the ketogenic diet on low-carb days, but the two methods should not be mixed. The keto diet often consumes many fats and not necessarily enough protein, and the goal in this diet is to get into ketosis.
This is hardly possible with carb cycling and the low-carb days have a different purpose - namely that the engine is always stimulated to work efficiently by the change of fuels and can also always recover systems. Learn more about the keto diet here!
Can you lose weight with Carb Cycling?
Carb cycling is not about losing weight, but rather about building muscle. In any case, body fat can also be reduced again because more muscles also burn more body fat. However, if the primary goal is body fat reduction or weight loss, you should look for a different nutrition concept. Pure fat loss - predominantly in the midsection of the body - works best when blood sugar is stabilized, which can often be achieved with a low-carb phase and, of course, sufficient fitness training.
So, the right nutrition strategy and method always depends on the body's starting point, personal goals, training, activity level in everyday life, as well as regeneration factors such as sleep and micronutrient supply.
There is no right or wrong for everyone, but only the individual diet that suits you and enables you to live a lifestyle that makes you feel good in the long term and sustainably.