Refeed day

Refeed day is a nutritional strategy where caloric intake is increased, using a higher amount of carbohydrates.

For a more in-depth review, see the complete guide to proper nutrition — a fundamental guide from the expert team at Sport Zona.

What it is

A refeed day represents a planned, short-term period of increased caloric intake, strictly controlled and focused primarily on carbohydrate consumption. Unlike "cheat meals" or "cheat days," which often involve uncontrolled intake of all kinds of foods, a refeed day is a structured part of the diet, aiming for specific physiological adaptations. It is usually implemented during periods of caloric deficit, when the goal is fat loss, incorporated once or twice a week, depending on the intensity and duration of the deficit, as well as individual needs.

The main biochemical essence of a refeed day lies in stimulating leptin – a hormone produced by fat cells that plays a key role in regulating appetite, metabolism, and energy balance. During prolonged caloric deficit, leptin levels drop, which can lead to a slowdown in metabolism, increased hunger, and reduced energy. The increased carbohydrate intake on a refeed day is the most effective way to temporarily boost leptin, signaling to the body that there is no energy shortage and it can maintain optimal metabolic function.

How it works

The mechanism of action of a refeed day is multifactorial and involves several key pathways. First, high carbohydrate intake leads to increased insulin production – an anabolic hormone that facilitates the transport of glucose to muscle and liver cells, where it is stored as glycogen. Replenishing glycogen stores is essential for maintaining high energy levels, optimizing training performance, and preventing muscle breakdown. Second, as mentioned earlier, carbohydrates are the most potent stimulator of leptin. Increased leptin has a cascading effect on other hormones, such as thyroid hormones (T3), which regulate metabolic rate. A drop in T3 levels is a common side effect of long-term caloric deficit, and a refeed day can help partially restore them. Third, the psychological aspect should not be underestimated – the opportunity to consume larger amounts of food, especially carbohydrates, can improve mood, reduce feelings of deprivation, and support long-term adherence to the diet.

In summary, the main effects of a refeed day on the body include:

• Restoration of muscle and liver glycogen.
• Increased leptin levels.
• Improvement of thyroid hormones (T3).
• Improved mood and reduced feelings of deprivation.

Why it's important for athletes

For athletes, especially those in a fat loss phase or preparing for competition, where a prolonged caloric deficit is maintained, a refeed day is an important tool for optimizing results and preventing negative adaptations. Chronically low energy levels and depleted glycogen can lead to a significant drop in training performance, strength, and endurance. Replenishing glycogen stores through a refeed day allows athletes to maintain the intensity of their training, which is crucial for preserving muscle mass during weight loss. Recommendations for carbohydrate intake on a refeed day vary, but often reach 6-10 g/kg of body weight, depending on individual metabolism and activity level, while fat intake is kept minimal, and protein intake remains at usual levels (around 1.6-2.2 g/kg of body weight, according to ISSN).

In addition to physical performance, a refeed day plays a key role in maintaining the psychological well-being of athletes. Prolonged deficit can lead to increased cortisol levels (stress hormone), irritability, sleep disturbances, and impaired concentration. Periodic "resetting" of these stress factors through a refeed day helps maintain focus and motivation, which is critical for long-term success in athletic achievements. Scientific data indicates that proper implementation of this strategy can contribute to more sustainable fat loss without unwanted metabolic adaptations that would otherwise hinder the process.

Related concepts

• Carb cycling — Carb cycling is a broader strategy that varies carbohydrate intake daily or weekly, and a refeed day can be part of it as a high-carb day.
• Caloric surplus — Unlike a caloric surplus, which is a constant state of consuming more calories than needed, a refeed day is a short-term and controlled increase in calories, often in the context of a caloric deficit.
• Glycogen — A refeed day is directly related to glycogen, as its main goal is to restore depleted muscle and liver glycogen stores through increased carbohydrate intake.
• Metabolic flexibility — By regulating hormonal response and improving the body's ability to switch between using fat and carbohydrates for energy, a refeed day contributes to improving metabolic flexibility.