Have you ever heard of glycogen overload? In other words, it is also nicknamed the spaghetti diet!
GLYCOGEN, RESERVES IN LIMITED QUANTITY!
When an individual consumes carbohydrates, a source of energy found in many foods such as fruits, grain products and legumes, the body makes glycogen stores. These famous reserves are located mainly at the level of the muscular tissues and the liver. On average, an individual has between 400-500g of glucose in the form of glycogen. Knowing that each gram of carbohydrate provides 4 calories, glycogen stores are between 1600 and 2000 calories. It takes just 24 to 48 hours without carbohydrates to completely deplete our reserves.
HOW TO INITIATE GLYCOGEN OVERLOAD?
This overload protocol is generally recommended for sports people who wish to improve their performance during a high intensity endurance event of more than 2 hours such as a half marathon or triathlon. To do this, it is necessary to change the distribution of our nutrients on our plate. While generally the balanced plate is composed of a quarter in grain products, a quarter in meats and substitutes and half in vegetables, 3 days before the day, it is recommended to reduce our portions of vegetables and proteins and instead opt for meals composed of 75% starchy foods.
This is the perfect time to make pasta, order sushi or eat pancakes with fruit and maple syrup.
DO YOU KNOW THE YO-YO EFFECT?
Generally used to address the rebounds of weight following restrictive diets, the yo-yo effect is also addressed to glycogen overload. Indeed, before starting our 3 days of overload, it is suggested to practice a training session of 90 minutes and more without snacks or beverages for athletes rich in carbohydrates to empty our current reserves. Thus, the body being deprived will have the reflex to rebuild its reserves in greater quantity during the recovery. A word of caution, your weight may fluctuate slightly during the process as each gram of carbohydrate is stored with 3 grams of water.
WHITE BREAD OR BROWN BREAD?
With the intention of making healthy choices, brown bread would seem to be better. However, during a glycogen overload where the ¾ of our plate is composed of carbohydrates, it is possible that a surplus of fibers generates you digestive discomforts and harms your contributions because of their effect of satiation. You will not be hungry enough to consume sufficient quantities for your needs. It is therefore preferable to opt for refined and low-fiber products. 
Finally, be aware that if you have diabetes or have questions about this overload protocol, a nutritionist can certainly accompany you and prepare a process tailored to your needs and your sport.
Extenso - University of Montreal's nutrition reference center
Manual of Clinical Nutrition, Professional Order of Dietitians of Quebec, Sports Nutrition