An assessment of the nutritional intake of soccer referees

Analysis of Sports Supplement Consumption of Elite Referees of the Spanish Professional Fotball League

BACKGROUND

Sports supplements (SSs) are widely used among team sport athletes; however, evidence supporting the use of SSs among football referees at the elite level is scarce. The aim of the present study was to analyze the consumption of SSs among referees with respect to their level of competition and referee type (main referees (MRs) vs. assistant referees (ARs)).

METHODS

A total of 106 football referees participated in this study, with 46.2% from the First Spanish Division and 53.8% from the Second Spanish Division, representing 84.13% of the total number of referees. Each participant completed a validated questionnaire about SS consumption, with the SSs classified according to the Australian Institute of Sport (AIS) ABCD system: Group A has strong evidence for enhancing athlete health and performance, Group B shows potential benefits but needs more evidence, Group C has inconclusive evidence against use, and Group D includes prohibited substances.

RESULTS

A total of 84.0% of the MRs and ARs reported the consumption of at least one SS. Differences were found only in the consumption of medical supplements between division (p = 0.016) and type of referee (p = 0.041), though no significant differences were found among the remaining AIS SS categories (p > 0.05). Sport performance (49.6%), Internet (41.0%), and dietitian-nutritionists (31.7%) were the primary reason for SS consumption, purchase location, and source of information, respectively. The most frequently consumed SS were whey protein (45.3%), followed by creatine (33.0%), sport bars and sports drinks (28.3%), and caffeine (19.8%).

CONCLUSIONS

MRs and ARs reported a high prevalence of dietary supplement (SS) consumption, with significant differences between division and referee type observed only in medical supplement consumption.

A Systematic Review of the Physical, Physiological, Nutritional and Anthropometric Profiles of Soccer Referees

BACKGROUND

The importance of soccer referees is widely accepted by international soccer organizations and governing bodies, although there is little research summarizing and appraising the literature on soccer referees. The aim of this study was to systematically review the information related to physical demands, nutrition and physiological profiling of soccer referees.

METHODS

Conforming with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, searches of three electronic databases (Web of Sciences, PubMed and Scopus) were conducted on 24 April 2022. The following search terms were used: (Soccer OR football AND refer*) AND (physical OR physiolo* OR load* OR "body composition" OR "fat mass" OR "fat free mass" OR "body size" OR "nutrition*" OR "nutritional assessment" OR "nutritional intake" OR "macronutrient*" OR "micronutrient*"). The inclusion criteria of the manuscripts written in English were that articles with male and/or female soccer referees and included relevant data concerning performance, physical testing, nutrition, body composition, body size and/or physiology of soccer referees. The tools developed by the National Institute of Health were used to assess risk of bias according to the study design.

RESULTS

In total, 110 manuscripts were included in the present review. Match activities of soccer referees and assistant referees are not comparable. Variation in performance is influenced by competitive level and competitive schedules. Additionally, match performance is often used to validate field protocols. The associations between match indicators and field protocols were not constant across the included studies, particularly in short-maximal tests. An age decline in physical performance was not conclusive. Body size did not discriminate between referees and assistant referees, as well as referees of different competitive levels. Few studies focused on nutritional guidelines among referees, particularly exercise energy expenditure. Energy intake was comparable across studies, but referees did not follow the daily dietary recommendations. Aerobic output was frequently assessed, and it was not comparable to the values for soccer players.

CONCLUSIONS

Although there are decreases in the running profiles of older referees, they maintain the same distances from the ball, and thus, age per se should not be used to define participation at the international level. The assessment of physical fitness warrants future consideration given the levels of fatigue that are apparent at the end of matches. In order to attain ideal levels of body composition, future studies need to provide guidelines for daily energy expenditure and nutritional intake.

TRIAL REGISTRATION

The protocol was published in INPLASY (International Platform of Registered Systematic Review and Meta-Analysis Protocols) with the registration number 202280052 and https://doi.org/10.37766/inplasy2022.8.005 .

Effect of body composition on the athletic performance of soccer referees

Nutrition plays an important role in improving sports performance. The present study aimed at nutritional assessment and examined the relationship between athletic performance and body composition in soccer referees at different levels. The study participants were 120 male soccer referees. 5, 10 and 30 metres (m) sprint tests to measure speed and cooper test for physical fitness were applied in the referees. Participants were divided into two groups as city and class soccer referee. The anthropometric measurements, excluding fat mass (FM) (%), were higher in class referees. Fat mass (%) differences (14⋅1 ± 4⋅28 v. 12⋅3 ± 4⋅41) were statistically significant (P < 0⋅05). Daily energy and nutrient intakes were similar. The inadequacy percentages of energy, vitamin A and calcium were the highest (29⋅2, 30⋅0 and 34⋅2 %, respectively). It was found that a negative significant correlation between FM% and cooper test score (P < 0⋅01; r = -0⋅35), a positive significant correlation between FM% and 5, 10 and 30 m sprint test scores (P < 0⋅01, r = 0⋅38; P < 0⋅01, r = 0⋅38 and P < 0⋅01, r = 0⋅48, respectively). Similarly, there was a negative significant correlation between waist circumference (WC) and cooper test score (P < 0⋅01; r = -0⋅31), a positive significant correlation between WC and 5, 10 and 30 m sprint test scores (P < 0⋅01, r = 0⋅33; P < 0⋅01, r = 0⋅40; P < 0⋅01, r = 0⋅33, respectively). Nutritional recommendations for soccer referees should be made specific to the individual, considering body composition, training intensity and match frequency by a dietician.

Individualized Breakfast Programs or Glycogen Super-Compensation: Which Is the Better Performing Strategy? Insights from an Italian Soccer Referees Cohort

The role of soccer referees has grown in importance in the last decades, as has attention to their performance, which may be influenced and improved with specific and evolved training programs. Today, multiple specialists are working as a team in order to develop effective training programs. Moreover, for athletes, it is becoming more and more important to be attentive to nutrition. By considering such items, in this study, we aimed to investigate the nutritional habits of a group of referees belonging to the Italian Soccer Referees' Association (on behalf of AIA-FIGC). Our main aim was to spread a "culture of nutrition" in refereeing, starting with a survey on referees' breakfast attitudes and in order to disseminate such a "culture", we chose top-level elite referees who were younger subjects (despite the average 4 years' experience). Therefore, we enrolled 31 subjects (aged 22.74 ± 1.79, BMI 22.30 ± 1.53) and asked them about their breakfast habits. Then, for measuring their performance, we used the conventional fitness test named Yo-Yo (YYiR1), performed in three different sessions (test 1, test 2, test 3). Test 1 was carried out without any nutritional indications, test 2 was given after individualized breakfast suggestions by a designed dietician, and test 3 after an individualized glycogen super-compensation strategy. The Wilcoxon statistical analysis indicates that following an individualized breakfast strategy may enhance referees' performance (p < 0.0001), whereas no significant effects were observed with the glycogen super-compensation option. However, further studies will be necessary to better address this topic and clarify whether high-carbohydrates (high-CHO) intake may be useful in other sports.

Eating Habits and Body Composition of International Elite Soccer Referees

Soccer referees are a specific group of the athletes' population whose careers peak from 30 to 45 years old. An athlete's performance is not only determined by physical training but also by a lifestyle, e.g. eating habits. The purpose of this study was to verify current eating habits and resulting body composition of a group of elite international soccer referees. At an international FIFA seminar 60 elite international soccer referees (aged 39.2 ± 4.2 years) were enrolled. A body composition assessment was performed with skinfold thickness and bio impedance analysis, while eating habits were evaluated with a multi-pass 24-hour dietary recall. The body composition showed a normal weight condition with a fat content of 11.4 ± 2.5%. Macronutrients showed a low level of carbohydrates (43.6 ± 5.4%) and a high level of fat (40.0 ± 4.5%). Micronutrients showed a low level of calcium, potassium, zinc, magnesium, iodine, vitamin B12 and vitamin B9. Even though their body composition was within the normal range, the current eating habits of elite international soccer referees did not appear to follow the nutrition guidelines. Therefore, it would be advisable to provide knowledge on nutrition for this particular category of sports subjects, an individualized nutritional plan would be advisable, in order to achieve and maintain better performance and appropriate body composition for their role.