While exact carb cycling plans vary based on the individual, a beginner carb cycling plan involves three “carb days” followed by four “off days,” says Libby. (Ideally, a beginner carb cycling plan should have three carb days followed by three off days, not four, but this is tricky to maintain in a seven-day week, says Libby.)
In order to burn through glycogen stores and then build them up again, these days need to be in consecutive blocks (so not one day on, one day off). So in a seven-day carb cycling plan, you might want to put your carb days over the weekend and your off days during the week.
The appropriate amount of carbs to eat on these days depends on the person, explains Libby. “Everybody’s liver holds about 70 grams of glycogen,” he says—that’s pretty consistent. However, that’s just the liver. How much muscle mass a person has will determine how much glycogen they can store—the more muscle mass, the more storage space. A good rule of thumb is to keep it to about 100 to 150 grams of net carbs per day, Libby says—that means the grams of carbs minus the grams of fiber.
On carb days, it’s also important not to dive into all those carbs at once. Eating large amounts of carbs in one sitting spikes your blood sugar quickly, and the carbs that can’t be stored in the cells, muscles, or liver end up being stored as fat, says Libby. (Not to mention, you’re in for an intense blood sugar crash later on.) Instead, spread your carbohydrates out throughout the day, tapering them off at night, says Libby. The energy carbs provide will do you more good at breakfast and lunch to keep you fueled throughout the day, he says—they’re not as important at dinner (unless you’re, say, going for a night run). Dr. Cole would agree with this not going overboard on the carbs sentiment. “Generally, I do not suggest increasing carbohydrates above 150 grams of net carbs, especially in people who tend to have carb sensitivities such as those with insulin resistance, diabetes, inflammatory issues, or those who have more than 10 pounds of weight to lose.” he explained.
After three days of filling up your glycogen stores with carbs, the next phase is to deplete those stores by cutting them out altogether—this means four days of eating as close to zero grams of carbs as you can get. Some trainers and nutritionists allow for a small amount of carbs on very high-intensity workout days, he notes, but he prefers to keep it as close to no-carb as possible. (Fair warning: On no-carb days when you work out, you can expect to be a little more fatigued than usual.)
After four no-carb days, it’s time to replenish your glycogen stores again for three days, and the process repeats itself. “After you’ve depleted the carbs, your body is going to be able to store more carbohydrate when you reintroduce them,” says Libby.