Aerobic Fitness in Top-Class Soccer Referees.

Castagna, C, Bizzini, M, Araújo Póvoas, SC, Schenk, K, Büsser, G, and D'Ottavio, S. Aerobic fitness in top-class soccer referees. J Strength Cond Res 33(11): 3098-3104, 2019-The aim of this study was to examine the aerobic fitness status of top-class male soccer officials using a cross-sectional design and known population group constructs. Fifty-two field referees (FRs, age 38.4 ± 3.3 years; height 181 ± 5.6 cm; body mass 76.8 ± 6.8 kg; body mass index [BMI] 23.4 ± 1.7 kg·m; body fat 20.4 ± 3.6%; and international refereeing experience 5 ± 3.5 years) and 104 assistant referees (ARs, age 37.8 ± 4.1 years; height 176.9 ± 7.5 cm; body mass 72.1 ± 7.4 kg; BMI 23 ± 1.6 kg·m; body fat 19.2 ± 3.6%; and international refereeing experience 7 ± 3.8 years) from 53 National Football Associations worldwide, and candidates of the preliminary open-list developed by the FIFA Refereeing Department for the 2014 World Cup Final Tournament, were tested for aerobic fitness in laboratory conditions with a progressive speed treadmill test to exhaustion. Large (+8.54%, d = 0.8) and small (+3.1%, d = 0.3) differences in absolute (L·min) and relative (ml·kg·min) VO2max were found between FR and AR, respectively. Trivial differences (d = 0.07) were shown in running economy (RE) (6 minutes at 8 km·h) between AR and FR. Using the scaling notation (b = 0.64), medium and significant differences were found between match officials for VO2max and RE (FR > AR; d = 0.6 and 0.67, respectively). Using receiver operating characteristic curve statistics, cutoff values of 3.93 L·min and 50.6 ml·kg·min were detected in absolute and relative VO2max for the FR and the AR (FR > AR), respectively. The FR showed superior aerobic fitness compared with AR. Training prescription should consider intensities at anaerobic threshold speed (14 km·h, 91% heart rate max) when aerobic fitness development is the aim in elite officials.

Ecological Validity and Reliability of an Age-Adapted Endurance Field Test in Young Male Soccer Players.

Castagna, C, Krustrup, P, D'Ottavio, S, Pollastro, C, Bernardini, A, and Araújo Póvoas, SC. Ecological validity and reliability of an age-adapted endurance field test in young male soccer players. J Strength Cond Res 33(12): 3400-3405, 2019-The purpose of this study was to examine the reliability and the association with relevant match activities (ecological validity) of an age-adapted field test for intermittent high-intensity endurance known as Yo-Yo intermittent recovery level 1 children's test (YYIR1C) in young male soccer players. Twenty-eight young male outfield soccer players (age 11.1 ± 0.9 years, height 142 ± 4.4 cm, body mass 37.0 ± 5.9 kg) with at least 2 years of experience in soccer competitions were tested twice using YYIR1C and an age-adapted competitive small-sided game (i.e., 9v9), 7 days apart in a random order. The YYIR1C performance showed an excellent relative (intraclass correlation coefficient = 0.94) and a good absolute reliability (typical error of measurement as percentage of the coefficient of variation = 5.1%). Very large and significant associations were found between YYIR1C performance and match high-intensity activity (r = 0.53). Large correlations were found between YYIR1C and match sprinting (r = 0.42) and high-intensity metabolic power (r = 0.46) distances. Match total distance was largely associated with YYIR1C (r = 0.30). The results of this study showed that YYIR1C may be considered a valid and reliable field test for assessing intermittent high-intensity endurance in young male soccer players. Because of the relevance of aerobic fitness in youth soccer, future studies testing the sensitiveness of YYIR1C are necessary.

Sex Differences in Aerobic Fitness in Top-Class Soccer Referees.

Castagna, C, Bizzini, M, D'Ottavio, S, and Araújo Póvoas, SC. Sex differences in aerobic fitness in top-class soccer referees. J Strength Cond Res 32(11): 3216-3221, 2018-The aim of this study was to assess the aerobic-fitness differences between male and female top-class soccer field referees (FRs). This with the purpose to provide cutoff values useful for training prescription in female FRs. Forty female top-class FRs (age 34.18 ± 3.50 years and 5 ± 3.9 years international refereeing experience) and 52 male FRs (age 38.4 ± 3.3 years and 5 ± 3.5 years international refereeing experience) candidates in the preliminary open list developed by the FIFA Refereeing Department for the 2014 and 2015 World Cup Tournaments, participated in the study. The FRs were tested for aerobic fitness under laboratory conditions with a progressive speed treadmill test until exhaustion. Female FRs showed to possess, on average, lower (large effect) levels of aerobic fitness and performance compared with their male counterparts. The female FRs' V[Combining Dot Above]O2max (48.1 ± 4.4 ml·kg·min) was 7% (large effect) lower than the male FRs (51.9 ml·kg·min). Peak treadmill speed was 11% lower (large effect) in female FRs (16.27 ± 0.94 vs. 14.64 ± 0.96 km·h). The receiver operating characteristic curve analysis enabled cutoff values (47.8 ml·kg·min for V[Combining Dot Above]O2max) that may be used as preliminary cues to guide physiological selection and training prescription in female FRs aiming to officiate male-soccer matches. Only 2.5% of the female FRs showed V[Combining Dot Above]O2max higher than the mean values of male FRs when using the scaled notation (0.68). Female FRs aiming to officiate male competitions should consider training intensities at anaerobic threshold speed (13 km·h, 95% heart rate max) when developing aerobic fitness. Given the very large sex differences in aerobic performance, strength/power training should be proposed to perspective female top-class FRs.

Fitness assessment in talented football referees: an academy based longitudinal field-study.

BACKGROUND: This study aim was to profile physical fitness in talented football referees (FR) with performance relevant field-tests across time. METHODS: Thirty-eight male FR (age 28±1.5 years, height 178±5.1 cm, body mass 69.0±7.34 kg, body fat 17.2±2.87%) were observed for 15 months. Endurance was assessed with the yo-yo intermittent recovery test level 1 (YYIR1) and repeated sprint ability (RSA) with 5×30 m line-sprints with 30 s recovery (5×30 m). Long sprint endurance (LSA) and change of direction ability (COD) evaluated with novel field-tests. FR was tested six times (every three months) during the study. RESULTS: YYIR1 performance showed large increments across testing occasions. Sprint time in the COD largely and significantly decreased across the testing occasions. Very large associations were reported between 5×30 m and LSA tests grand mean (r=0.89, 0.78-0.94, P<0.0001). A nearly perfect (r=0.97, 0.94-0.99, P<0.0001) association was observed between 5×30 m best sprint and 5×30 m grand means. CONCLUSIONS: The results of this study revealed ability-related variations in performance across time. The effect of training and competitions on the determinism of physical fitness in refereeing seem plausible. Interestingly, sprint endurance tests shared a very large variance proposing tests interchangeability and mutual physiological demands. This study information provides useful information for the development of sound field-tests batteries in talented FR.