# A Systematic Review of the Effects of Nutrient Intake in Handball Players on Exercise Performance
## 4 Discussion
### Energy  
Adequate energy intake is the cornerstone of the handball athlete's diet to support optimal body function and body composition management [10]. Among the many factors that can influence an athlete's energy requirements, such as training/competition cycle, exposure to cold, heat or altitude, injury or age, in handball it also becomes critical to aim for a certain body composition. To estimate the caloric expenditure of the handball athlete, we find innumerable methods with different advantages and complications [74]. [PERSON] and [PERSON] (2019) [38] estimated by the Cunningham equation and metabolic equivalents (MET) TEE of 4054 \(\pm\) 248 kcal; 4587 \(\pm\) 289 kcal; and 3413 \(\pm\) 193 kcal for men; and 3173 \(\pm\) 176 kcal; 3602 \(\pm\) 218 kcal; and 2646 \(\pm\) 108 kcal for women on training, match and rest days, respectively. On the other hand, [PERSON] et al. 2020 [37], using [PERSON] and [PERSON]'s equation (use of HR during activity), estimated similar TEE values of 3000 \(\pm\) 228, 3322 \(\pm\) 253 and 2933 \(\pm\) 208 kcal during 3 days of training in female handball court players, giving 1126 \(\pm\) 116, 1478 \(\pm\) 209 and 1103 \(\pm\) 143 kcal to energy expenditure per handball training session on all 3 days, fluctuations caused by the performance of a double session on the 2 nd day. [PERSON] et al. 2013 [22] estimated by means of pedometers EE during matches of 439.17 \(\pm\) 142.81 kcal with distances covered of 3062 \(\pm\) 746.3 metres, although these data must be interpreted correctly, being aware that these devices may have limitations when recording the intensity, frequency and duration of PA, in addition to the movements of the upper body so characteristic of handball [75; 76]. Another interesting study by [PERSON] et al. (2017) [44] observed TEE values of 3126 \(\pm\) 520 kcal for female and 3892 \(\pm\) 596 kcal/day for male indoor handball athletes at the beginning of the season using CI and DLW techniques, with a considerable increase in TEE during the main competition phase (average PAEE from 1622 \(\pm\) 563 kcal/day to 2030 \(\pm\) 464 kcal/day) to values of 3549 \(\pm\) 317 kcal/day for women and 4526 \(\pm\) 483 kcal/day for men, results that underline the importance of adequate nutritional planning that considers the different stages of the season. In their application to movements and exercises specific to the sport of handball, [PERSON] et al. (2021) [42], via spiro-ergometry, observed EE ranging from 12.36 to 15.52 kcal/min during performance tests based on typical handball court exercises. Studies of this type can also be of great use in extracting and interpreting different practical tools for the measurement of EE in sport and activity in particular, such as the LPM system or inertial sensors, for example [77; 42]. The application of these methods is necessary in beach handball to analyse the specific EE of this sport, although lower demands than in indoor handball are speculated, taking into account factors such as playing time, field surface, number of players, etc. [7]. Based on these data, we observe that the vast majority of handball athletes, regardless of sex and category, do not have an adequate energy intake to cover the demands of physical activity [18; 25; 26; 28; 29; 30; 31; 32; 35; 36; 38; 39], with the study by [PERSON] et al. [35] showing the older adults' higher intakes in male goalkeepers compared to the lower intakes of female front lines (3837.1 \(\pm\) 1537.8 vs. 1802.6 \(\pm\) 798.1 kcal/day), data that are not in accordance with the demands of track handball athletes according to their playing position [78]. [PERSON] et al. 2022 [43] observed a prevalence of 9.68% of clinically low AD cases during the preparatory phase in a sample of athletes from different disciplines, including seven track handball athletes. Clinically low AE (<30 kcal/kg FFM/day) or unusual weight loss practices in handball athletes could also be the starting point for the diagnosis of eating disorders [79].