Before, during and after physical activity, hydration is a limiting factor in athletic performance. Therefore, adequate hydration provides benefits for health and performance of athletes. Besides, hydration is associated to the intake of carbohydrates, protein, sodium, caffeine and other substances by different dietary aids, during the training and/or competition by athletes. These requirements have led to the development of different products by the food industry, to cover the nutritional needs of athletes. Currently in the European context, the legal framework for the development of products, substances and health claims concerning to sport products is incomplete and scarce. Under these conditions, there are many products with different ingredients out of European Food Safety Authority (EFSA) control where claims are wrong due to no robust scientific evidence and it can be dangerous for the health. Further scientific evidence should be constructed by new clinical trials in order to assist to the Experts Commitees at EFSA for obtaining robust scientific opinions concerning to the functional foods and the individual ingredients for sport population.