If we consider the nutritional and energy requirements associated with ultra endurance sports, it is clear that athletes use nutritional supplements to improve their performance and recovery. Dietary supplements are defined as products that are taken to achieve nutritional, clinical and performance goals, in addition to an optimal normal diet. Supplementation is a frequently used strategy among many elite athletes and recreational athletes to meet the increased nutrient requirements induced by exercise, meet dietary recommendations, achieve sports nutrition goals, and improve athletic performance. From the point of view of macronutrient intake, carbohydrates play an important role in the supply and recovery of athletes in longterm endurance sports, while adequate protein intake is crucial for maintaining muscle protein synthesis and adequate immune function. In addition, numerous metabolic pathways, as well as many physiological mechanisms, are controlled by vitamins and minerals. That is why intake of vitamin and mineral supplements is more common than carbohydrate and protein supplements among the mentioned athletes. However, all categories of nutritional supplements can be an important source of micronutrient intake for athletes if there are deficiencies in their usual diet. The purpose of this thesis is to examine the current state of knowledge about nutrition and supplementation in ultra endurance sports and to provide a complete overview of the latest research results. Specifically, this paper, based on studied literature sources, will show the role of macronutrients (carbohydrates, protein and fat), micronutrients (vitamins and minerals), hydration, nutritional supplements (such as caffeine, creatine, ashwagandha, nitrates and probiotics) and different dietary patterns in improving ultra endurance and promoting recovery.