Abstract
<jats:p>The International Association of Athletics Federations recognizes the importance of nutritional practices in optimizing an athlete's well-being and performance. Dietary supplements offer ergogenic aid in an attempt to increase energy, improve recovery, modulate body composition and control muscle acidity (number of free protons, acidosis), enabling improved performance. This book aimed to realize a bibliographic review to highlight the main approaches and clinical outcomes of sports nutrition. The International Association of Athletics Federations recognizes the importance of nutritional practices in optimizing an athlete's well-being and performance. In this regard, periodized guidelines can be provided for the appropriate type, quantity, and timing of food and fluid intake to promote optimal health and performance in different training and competition scenarios. Therefore, the use of medical supplements to address nutrient deficiencies or sports foods to help athletes achieve nutritional goals is well-known. The most common examples of supplements are caffeine, bicarbonate, beta-alanine, nitrate, creatine, glutamine, and iron ions. Dietary supplements offer ergogenic aids by attempting to increase energy, improve recovery, modulate body composition, and control muscle acidity (number of free protons, acidosis), enabling improved performance. As a first example, increasing beta-alanine availability through dietary supplementation, combined with training, can improve the performance of athletes performing high-intensity exercise by increasing muscle buffering capacity (reducing acidity). As another example, early research reported that NaHCO3 was effective in improving short-duration, high-intensity exercise capacity, while more recent studies have shown that NaHCO3 can also improve performance during aerobic endurance and prolonged, high-intensity intermittent exercise. Besides, glutamine is involved in several biological functions, such as nucleotide synthesis, cell proliferation, regulation of protein synthesis and degradation, energy production, glycogenesis, ammonia detoxification, and maintenance of acid-base balance, among others. Furthermore, this amino acid regulates the expression of several genes associated with metabolism and activates several intracellular signaling pathways. Glutamine metabolism has been investigated during and after physical exercise, and it has been observed that blood glutamine responds differently depending on the duration of exercise. Furthermore, iron is essential for oxidative metabolism and is therefore especially important for endurance athletes whose athletic performance depends on high aerobic capacity.</jats:p>