Somatotype of Iranian Soccer Premier League Players

Aim: The aim of the present study was to examine the somatotype of elite soccer players based on positions. A total of 232 elite male soccer players (24.14±5.15) participated in this study. Methods. All anthropometric measurements (10 variables) were performed by a criterion anthropometrists according to the standards of the International Society for Advancement of Kinanthropometry (ISAK). Heath-Carter Somatotyping method was used to calculate endomorphy, mesomorphy and ectomorphy components. Results. The mean body mass and height were 76.29 ± 7.96 kg and 180.42 ± 6.82 cm, while the mean somatotype values were 1.89 ± 0.60 4.91 ± 0.80 2.65 ± 0.77. Somatotype, height and body mass of the goalkeepers showed a significant difference with the other positions. Conclusion. The findings of this study provide a valuable reference data to support soccer talent identification programs and development of more specific preparatory strategies for soccer.


Introducción
Soccer is the most popular sport discipline in the world. Iran is a top-ranking country in the Asian Football Confederation (AFC) and has a professional league (Persian Gulf League). There are numerous physical indicators for soccer performance. Anthropometric characteristics are important indicators and have the potential to influence soccer players' success (Norton and Olds 1996). A review of literature has shown that height, body mass, body fat percent and somatotype are some of the important anthropometric characteristics related to performance (Norton and Olds 1996).
Somatotype is a very important characteristic that can be used as an indicator of elite athletic suitability. This parameter, combined with body composition and proportionality indices, could be used in the talent identification programs. There is a large amount of data in the literature about the suitability of different somatotype patterns not only for sport disciplines, but also for intra-sport positions, events and weight categories. Although,

Material and Methods
A total of 232 male soccer players from Iranian Professional premier league (Persian Gulf League) voluntarily participated in the study. All players were regularly involved in competitive training and matches. Mean age of the subjects was 23.54 ±4.86 years old. All subjects were professional players with at least two years of playing experience in the league. The distribution across various positions was goalkeeper (n=26), defender (n=66), midfielder (n=81), and striker (n=59).
This research was performed in compliance with the 1964 Helsinki Declaration. All experimental procedures were in accordance with the rules of the Ethical Committee of the Centre for Strategic Studies, Iranian Sport and Youth Ministry. All subjetcts signed informed-consent forms. The inclusion criteria was to be a member of one of the Iranian Premier League soccer clubs and the main exclusion criterion was injuries that prevented training and competition.
Data were collected in the clubs' training facilities during first weeks of the season and positions were recorded based on the validated data.
Measured anthropometric variables were height, body mass, two bony breadth (biepicondylar, humerus and femur), two girths (arm girth tensed and flexed, maximal calf girth), and four skinfolds (Triceps, Subscapular, Supraspinale, and Medial Calf). All measurements were done by an ISAK criterion anthropometrist following the protocols from the International Society for the advancement of Kinanthropometry (ISAK) (2011) . Somatotype was determined according to Heath-Carter somatotyping method (Carter et al. 1990 ). Somatotype Attitudinal Distance and Somatotype Attitudinal Mean (SAM) were also determined (Carter et al. 1990).
The body mass was measured by a weighing scale ( Seca 707) to the nearest 0.1 kg. Stature was measured by a stadiometer ( Seca 206). Skinfolds thicknesses were taken using the Harpenden Skinfold Caliper (British Indicators Ltd, Luton) to the nearest 0.1 mm, and girth measurements were done with a flexible metallic tape (Lufkin w606PM, Mexico), with a precision of 1 mm. Bi-epicondylar Bone breadth were also measured with a Tommy 2 bone caliper (Rosscraft).

Results
The mean body mass and height were 76.29 ± 7.96 kg and 180.42 ± 6.82 cm, while the mean somatotype values were 1.89 ± 0.60 -4.91 ± 0.80 -2.65 ± 0.77. Also, the basic data and somatotype values of the soccer players based on positions were presented in Table 1 and distribution of somatotype values of each position (somatocharts) were shown in Figure 1.

Figure 1
Position distribution of the subjects in somatocharts for goalkeepers, defenders, midfielders and strikers.
One-way ANOVA identified significant differences (P<0.05) amongst players positions for height, body mass, and endomorphy values ( Table 1). The post-hoc Tukey tests indicated that goalkeepers were heavier, taller and had greater endomorphy values (P<0.05).

Discussion
The results of the present study shows a significant differences between the goalkeepers and the other players. In some previous studies, some similar trends have been reported. In Tables 2 and 3, mean somatotype of soccer players from different countries, and data related to different positions are shown respectively. Reilly et al.( 2000 ) reported significant differences in a variety of anthropometric variables , most notably in stature and body mass, perhaps suggesting that these variables include a morphological optimization within soccer and found that relative heterogeneity in body size was is a characteristic of elite soccer teams. Thus so anthropometric differences were therefore expected between playing positions . A study was conducted by Gil et al. (2007) in soccer players, aged between 14 and 19 years. The study showed similar values in endomorphy and mesomorphy and a decrease with age only in ectomorphy component (Gil et al 2007).
Previous studies had indicated that the somatotype of elite soccer players was dominated by a balanced mesomorph category. Ramadan and Byrd (1987) found that average somatotype values of defense players were balanced mesomorphic; average somatotype values of mid-fielders were ectomorphic mesomorph; average somatotype values of forward players and goalkeepers were endomorphic mesomorph; and average somatotype DOI: 10.34256/ijk21110 values of all players were balanced mesomorph (Ramadan et al.1987). Also Pelin et al (2009) found that average somatotype values of football players were balanced mesomorph. Ramadan and Byrd (1987) concluded that goalkeepers had significantly higher values for endomorphy (3.0) and mesomorphy (5.5) when comparisons were made by position (Ramadan et al. 1987) . Silvestre et al. (2006) reported that goalkeepers had more body mass than the rest of the team. The findings of Rienzi and his colleagues (2000) showed that goalkeepers had different somatotype characteristics compared to other positions (Rienzi et al. 2000). However, Orhan and his colleagues (2013) indicated that there was is no specific relationship between somatotype and playing position (Orhan et al. 2013). The research done by Martirasov and his colleagues (1987) on national junior team players of 10 different countries revealed that the somatotype values of the players were balanced mesomorph and ectomorphmesomorph in average (Martirasov et al. 1987). Rienzi et al. (1998) found that the somatotype values of South American football players were balanced mesomorph. Vivani et al. (1993) analyzed 19 football players and reported similar somatotypes of were 2.1 (endomorph), 5.2 (mesomorph) and 2.4 (ectomorph).

Conclusion
In conclusion, mean somatotype of male soccer players of the present study ectomorphic mesomorph. This is a constant pattern for all positions, except for goalkeepers. The Goalkeepers were balanced mesomorphs on average with greater adiposity than other positions. This findings are nearly close to somatotype patterns of Turkish super League (Hazir 2010), but there are differences with other studies especially those have been conducted with different age groups (Lago-Penas et al 2011, Gil et al 2007 or Sub-elite level subjects (Perroni et al 2015, Fidelix et al 2014.