Proper nutrition is a decisive factor of growth and development of a young organism. It has also a major impact on athletic performance. The aim of this paper is to discuss the basic principles of nutrition in sports training and health training. The size, composition and times of meals may have a huge impact on sports performance. Good dietary practices allow athletes to train hard, regenerate quickly, adapt better, while reducing the risk of illness and injury. Athletes should use appropriate nutritional strategies before and after their performances, so as to achieve the best results. They should pay special attention to the amounts of carbohydrates, proteins, fats, vitamins, minerals in their food:, as well as the amount of consumed fluids.