# A Systematic Review of the Effects of Nutrient Intake in Handball Players on Exercise Performance
## 1 Introduction  
Modern handball is a team sport originating in Scandinavia in the early 19 th century and was introduced as an Olympic sport in 1972 with the men's discipline and 4 years later at the Olympic Games in Montreal (Canada) with the women's discipline. It is considered one of the most popular team sports in Europe, played by more than 19 million people worldwide [1].  
Beach handball was born as an adaptation of court handball in the 1990s on the beaches of Italy and it is a modality that is nowadays consecrated by international bodies with championships in all parts of the world. This discipline has an origin closely linked to court handball, both modalities being complex and multifactorial ball games characterised by a fast pace and variable game intensities, as well as a strong influence of tactical concepts, social factors and cognitive aspects [2, 3]. Despite this, there are clear differences in tactics, regulations and the environment in which they are practised, and these differences in the cycles and phases of the game must be understood in order to understand each discipline properly [4, 5]. Therefore, although many of the actions performed in both disciplines are similar and are characteristic of high intensity contact sports such as blocking, passing, jumping, short distance running, etc., [6], they are different sports with different demands, court handball being a more physically demanding discipline than beach handball due tothe size of the court, the surface and the number of players [7]. Common factors such as nutrition, illness and injury, as well as external influences and environmental conditions can significantly influence sporting performance in both disciplines [2]. Therefore, it is becoming increasingly important to adjust the nutritional intake of handball athletes to try to meet their individual needs to cope with training and competition [8; 9; 10].  
However, knowledge of specific nutritional strategies during training and competition does not seem to be as clear in handball players. Similarly, energy, macronutrient and micronutrient requirements as well as hydration protocols are not clearly understood according to the physical demands and locomotor power production in handball athletes [11].  
Therefore, analysing the current lack of information linking food science and sports nutrition to the sport of handball, as well as the important role that an adequate total nutritional status (hydration, macronutrients, micronutrients, relationship with food and eating disorders, etc.) plays in the sports performance of different sports disciplines, it is clear that there is a need to study the habits, the needs/requirements and the different nutritional problems existing in handball athletes. For this reason, the objective of this systematic review is to analyse the nutritional status of beach and court handball athletes, both male and female, of any age range, level and category, to assess whether this is in accordance with the specific and general demands of sport in terms of fluid intake, energy, macronutrients and micronutrients, as well as whether there is a need to incorporate more professional work on sports nutrition in this population group.