Carbohydrates: Fuel or Foe in Endurance? Dr. Bárbara Silva Explains

Demystifying Carbohydrates and the Danger of REDS

One of the biggest myths addressed is the fear of consuming carbohydrates due to concerns about gaining weight. Dr. Bárbara clarifies that ideal weight and performance are a delicate balance. Prolonged caloric restrictions, especially chronic ones, exponentially increase the risk of injuries, fatigue, and REDS (Relative Energy Deficiency in Sport), leading to performance loss. While weight loss can initially reduce VO2, there's a fine line where this loss becomes detrimental.

A low-carb strategy can be valid, but only during specific periods, such as the pre-cycle or base phase, where an athlete might even gain a little weight. It's important to "carb cycle," adjusting intake according to training phases. Athletes who try to compete without carbohydrates, or who follow extreme restrictive diets, might finish the race, but they will never reach their maximum performance potential. The goal is to be "light and strong," not "light and weak."

Training the Gut: A Crucial Strategy

A significant challenge for endurance athletes is intestinal adaptation, known as training the gut. Dr. Bárbara explains that intestinal receptors (SGLT1 and GLUT5) function like "stadium gates"; the more developed and numerous they are, the greater the capacity for carbohydrate absorption. Studies, such as those with Maurten and marathon runner Sebastian Saue, show that gut training increases absorption capacity and reduces waste.

The endurance athlete's gut, especially for runners, suffers from blood diversion to the muscles and mechanical stress, resulting in hypoxia and reduced permeability. Therefore, gut health is paramount. Training involves dosing carbohydrate and fluid intake, gradually increasing it so the body adapts, minimizing discomfort and preventing gastrointestinal issues during races.

The Complexity of an Athlete's Life: Amateur vs. Professional

The amateur athlete's routine is particularly challenging, as they often lack the time for rest and recovery that a professional possesses. Comparisons with elite athletes, who have flexible schedules, access to infrastructure, and less daily stress, can be demotivating. Dr. Bárbara emphasizes that amateur athletes need to manage a range of responsibilities (work, family) in addition to training, making "resting like a pro" almost impossible.

It is fundamental for each athlete to understand their own limitations and conditions. The Ironman journey is an example: a long day with many variables, where "plan A, B, and C" is essential. Family, as in Dr. Bárbara accompanying her husband, is also an integral part of the challenge, requiring understanding and support. The transformation in endurance is not just physical, but also mental and personal, a true learning experience about oneself.

Warning Signs of Energy Deficit and the Rebound Effect

Dr. Bárbara also warns about the dangers of indiscriminate use of "weight-loss pens" by athletes, which can lead to severe and unsupervised caloric deficit. The point is not the tool, but professional guidance. Rapid weight loss can compromise VO2, increase tendon fragility, and raise the risk of injuries. Athletes with REDS often seek medical help when performance is already declining, but other signs include sleep disturbances, irritability, mood swings, and chronic injuries.

The transition from a deficit state to an efficient athlete is a slow and careful process. A body in restriction becomes a "saver," hoarding energy; to become a "burner," the body needs metabolic adaptations and a gradual increase in carbohydrate intake. It's a relationship of trust between athlete and professional, where each small improvement builds the credibility of the process. Caring for the basics, such as a balanced diet and conscious use of probiotics, is crucial to minimize the effects of constant stress on the endurance athlete's body.

Clearly, the world of endurance is full of nuances and challenges, but with the right knowledge and proper professional support, such as that offered by Stemma Performance, athletes can optimize their performance, ensure their health, and fully enjoy the journey, transforming carbohydrates from a supposed villain into their greatest ally.