Given the solid basis of its potential to improve exercise capacity, numerous investigations on KD and exercise have been carried out in recent years. It is also reported that a high-fat diet could contribute to mitochondrial biogenesis and reduce mitochondrial autophagy, thus contributing to a rich mitochondrial reservoir in the muscle, boosting exercise performance, and contributing to athletes’ wellbeing. Long-term KD administration is linked with reduced inflammatory mediators by down-regulating NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasome expression and reducing the generation of isoprostanes. Excessive free radicals and chronic inflammation are harmful to mitochondria, muscular cells, and whole-body health. Compared to glucose oxidation, fat-centered oxidation involves producing less reactive oxygen species during the process. Despite the potential to increase exercise performance and capacity, a KD may also contribute to muscle health by anti-inflammatory and anti-oxidative properties, thus preventing exercise-induced fatigue and muscle and organ damage. Compared to glucose, ketone bodies are more energy-intensive, while a ketone body-centered metabolism has the potential to provide a consistent, fast energy supply. In any case, the capacity for the body to reserve ketone bodies and fat is much stronger. Glucose oxidation requires 11 steps to produce energy, whereas fat and ketone bodies can quickly provide energy in only three steps. Over time, the body will acclimate to using ketone bodies as a primary fuel, which is called keto-adaptation, an element of fat-adaptation. This phenomenon is called nutritional ketosis. In this way, the liver is forced to produce and release ketone bodies into the circulation. Therefore, whether we can find an effective way to enhance fat utilization is an important question.Ī ketogenic diet (KD) involves using fat, a high-density substrate, as the main source in daily calorie intake while restricting carbohydrate intake. However, the abundant carbohydrates in traditional high-fat diets may restrict us from utilizing fat. A person of average weight may store 10 kg fat in the body, which makes the person capable of completing >30 marathon races if the stored fat is effectively utilized. The capacity for the human body to store carbohydrates is limited, which is 5 g glucose in blood circulation and ~100 g or ~500 g glycogen in skeletal muscle or liver. However, for excellent athletes competing in endurance sports, this strategy may lead to an awkward dilemma. Carbohydrate-loading is one of the main nutritional strategies to improve exercise performance before crucial events.

Traditionally, carbohydrate-centered diets have been recommended for sports. Our metabolic system is remarkably flexible in its ability to use a variety of dietary macronutrients as fuels.

Endurance sports