Body composition analysis of athletes from the elite of Brazilian soccer players
Análise da composição corporal de atletas da elite do futebol brasileiro
José Gerosa-Neto1,*; Fabrício Eduardo Rossi1; Camila Buonani Silva1; Eduardo Zapaterra Campos1; Rômulo Araujo Fernandes1; Ismael Forte Freitas Júnior1
1Departamento de Educação Física, Universidade Estadual Paulista (UNESP), Brasil
]]>
ABSTRACT
This study analyzed the body composition and bone mineral density of elite Brazilian soccer players and compared its differences according to the player position. Eighty-two soccer players competing at Brazilian first division were split according to their field positions: Goalkeepers (GK, n= 10), Back-fielders (BF, n= 10), Lateral-mid?elders (LM, n= 15), Central-mid?elders (CM, n= 25), Forwards (FW, n= 22), and a Control Group (CG, n= 72) of university students. To estimate fat free mass (FFM), fat mass (FM), percentage of body fat (%FM), fat free mass of legs (FFM-Legs) and bone mineral density (BMD), a DEXA was selected. The positions LM (10.5 ± 5.2), CM (9.7 ± 4.0) and FW (9.9 ± 4.4) had lower values of FM and %FM than the GK (17.3 ± 6.0) and the control group (15.0 ± 5.3). Compared to the other positions, FFM was higher in the GK (68.2 ± 10.9) and BF (64.6 ± 6.8) (p< 0.05). All the soccer players were different from the CG (p< 0.05). Soccer players have an FFM, FFM-Legs and BMD significantly higher and FM and %FM lower than the control group.
Keywords: athletes, muscle mass, bone density, DXA
RESUMO
Este estudo analisou a composição corporal e densidade mineral óssea de atletas da elite do futebol brasileiro e comparar as diferenças entre as posições de jogo. Oitenta e dois jogadores de futebol da primeira divisão do Brasil foram divididos de acordo com a posição de jogo. Goleiros (GL, n= 10), Defensores (DF, n= 10), Laterais (LT, n= 15), Centrais (CT, n= 25), Atacantes (AT, n= 22) e um grupo controle (CG, n= 72). Para estimar a massa livre de gordura (MLG), massa gorda (MG), percentual de massa gorda (%MG), massa livre de gordura de pernas (MLG-Pernas) e densidade mineral óssea (DMO), foi usado o DEXA. A posição LT (10.5 ± 5.2), CT (9.7 ± 4.0) e AT (9.9 ± 4.4) apresentaram menores valores de MG e %MG que os GL (17.3 ± 6.0) e GC (15.0 ± 5.3). Comparado a outras posições, a MLG foi maior nos GL (68.2 ± 10.9) e DF (64.6 ± 6.8) (p< 0.05). Todos os jogadores apresentaram diferenças significativas em relação ao grupo controle (p< 0.05). Em suma, conclui-se que atletas da elite do futebol brasileiro apresentaram significativamente maior MLG, MLG-Pernas, DMO e menor MG e %MG que o grupo controle.
Palavras-chave: atletas, massa muscular; densidade mineral óssea
INTRODUCTION
]]> Soccer is considered the most popular sport in the world, being practiced in almost all nations (Reilly & Williams, 2003), and as sporting performance evolves, concerns about the factors involved in its improvement increases, so that the monitoring of body composition variables to achieve better results becomes more important. Accordingly, given morphological characteristics obtained in the anthropometric assessments and in the body composition (body mass [BM], height, fat free mass [FFM] and fat mass [FM]) are important to excel in soccer.Due to the size of the soccer pitch and the duration of the game, each players performs one specific function within the team, showing specific physical characteristics (Davis, Brewer, & Atkin, 1992; Goulding et al., 2009; Silvestre, West, Maresh, & Kraemer, 2006; Sporis, Jukic, Ostojic, & Milanovic, 2009)
Aside from some research which has been carried out with these athletes (Carling & Orhant, 2010; Casajus, 2001; Davis et al., 1992; Franks, Williams, Reilly, & Nevill, 1999; Reilly, Bangsbo, & Franks, 2000; Rhodes et al., 1986; Rienzi, Mazza, Carter, & Reilly, 1998; Silvestre et al., 2006), sports science has been more dedicated to the studies of aerobic and anaerobic fitness, with less attention given to the morphological variables, which are generally studied by a bi-compartmental model of evaluation (BM= FFM+ FM).
Research having as main framework multi-compartmental models in which the body is split into three or more components is a must (Heymsfield, Wang, Visser, Gallagher, & Pierson, 1996), allowing a detailed study that takes into consideration the distribution of the FFM in a segmented way. Additionally, there are few studies that have investigated the body composition of Brazilian soccer players, and analyzed according to field position. Thus, the objective of the present study was to analyze the body composition and bone mineral density of athletes from elite Brazilian soccer teams and to compare the differences between the field positions.
METHODS The study has a cross-sectional design and was carried out in 2010 and 2011 at the University Estadual Paulista (UNESP) - Presidente Prudente - SP.
Participants The sample was split into two groups: 82 soccer players (23.6 ± 4.2 years, 179.9 ± 8.1 cm and 77.0 ± 12.7 kg) that can be broken-down into their position. The players were classified as forwards (FW, n= 22), goalkeepers (GK, n= 10), lateral-mid?elders (LM, n= 15), central-mid?elders (CM, n= 25) and back-fielders (BF, n= 10), players from the Brazilian soccer first division; and a Control Group (CG) which consisted of 72 university individuals (24.7 ± 4.8 years, 177.7 ± 5.6 cm e 76.5 ± 7.6 kg) who did not practiced systematic physical activity. These athletes competed in a league with 20 teams and the season lasted for 11 months of the year. Because there are only a few breaks over the season, data collection was done during the pre-season.
Instruments and Procedures
Anthropometry and Body Composition
Body mass was measured with an electronic weighting scale (Filizola®), with a maximum capacity of 180 kg and a precision of 0.1 kg. Height was measured with a fixed stadiometer (Sanny ®), with an accuracy of 0.1 cm and
a length of 2.20 m.
To estimate fat free mass, fat mass, percentage of body fat, fat free mass of legs and bone mineral density, an absorptiometry device for X-ray of Dual-energy (DEXA) of Lunar brand was used, DPX-MD, software 4.7 The DEXA body composition was estimated by dividing the body into three anatomical compartments: fat-free mass, fat mass and bone mineral density (BMD). Results are reported in grams of lean mass, fat and body fat percentage (Lohman, Roche, & Heymsfield, 1996). This technique also allows the estimation of total and segmental body composition. Thus we estimated the total body composition and lower limb.
The determination of the body regions was done according to Silvestre et al. (2006). All evaluations were performed in competitive pre-season.
Statistical Analysis For the statistical analysis the Kolmogorov-Smirnov test was used to verify the normality. After the descriptive analysis for the sample characterization, the t Student test for independent samples was selected to verify the differences between the soccer players and the control group. The Levene test for verifying homogeneity of variance of a data set was carried out in addition to One-Way analysis of variance (ANOVA) following the Tukey Post Hoc test in order to verify the possible differences between the player positions. All analyzes were performed using BioEstat software (version 5.0). The significance level was 5%.
RESULTS ]]> Table 1 presents the main characteristics of the soccer players and the control group. Comparing both groups a significant difference was observed in the soccer players for all the body composition variables and the height. There was no difference in age or weight.
Table 2 presents the different body compositions according to player position. The positions LM (10.5 ± 5.2), CM (9.7 ± 4.0) and FW (9.9 ± 4.4) had lower values of FM and %FM than both the GK (17.3 ± 6.0) and the control group (15.0 ± 5.3). Compared to the other positions, FFM was higher in the GK (68.2 ± 10.9) and BF (64.6 ± 6.8) (p< 0.05). No significant differences were verified in FFM-Legs among the athletes groups but all of them presented significantly higher values than the CG (p< 0.05).
DISCUSSION The aims of this study were (i) to analyze and compare body composition and bone mineral density in elite Brazilian soccer athletes with a control group, (ii) and to compare according to the field position. In this study the soccer players, when compared to the control group, showed differences in all variables, but for age and weight, showing the effect of specific training in this sport. The average percentage of fat found in soccer players was 14%, values similar to those found by Silvestre et al. (2006) (13.9%) and Matkovic et al. (2003) (14.9%) with first division players from Connecticut and Croatia respectively. However, they are all higher than those shown by Sutton, Scott, Wallace, and Reilly (2009) who evaluated four of the elite English soccer teams. These differences may be due to the instruments used and evaluation period (pre-season or period of competitions), as well as the competitive level of the participants. Gissis et al. (2006) analyzed the values of body fat in soccer players according to their competitive level in the Greek league teams, showing significantly lower values in the best placed teams. Sutton et al. (2009) showed that body fat and bone mineral density are the best variables to discriminate soccer players from the control group, according to multiple regression models, this effect was observed in the goalkeepers. In the study by Sutton et al. (2009) goalkeepers showed higher values of body fat percentage when compared to other field positions. These results are similar to those found in this study; however, goalkeepers only differed from midfielders and attackers. These differences in fat percentage between goalkeepers and defenders from the remaining positions may be due to the characteristics required in training and games. Reilly (1997) noted that goalkeepers and defenders run on average 4 and 8 km, respectively, in a match, while in other positions the distance can reach 12 km. So it is natural that goalkeepers would have a lower aerobic capacity and a higher percentage of body fat. Matkovic et al. (2003) and Arnason et al. (2004) reported greater differences between goalkeepers and other player positions, with goalkeepers being taller, heavier and having a higher fat percentage. In these two studies small differences between the other positions (goalies excluded) were also found. In this research, goalkeepers also had a higher absolute amount of fat-free mass compared to the control group, the laterals, midfielders and attackers. However, when only the fat-free mass of the legs was analyzed the difference found was only in relation to the control group. Sutton et al. (2009) used the percentage of fat-free mass and found no differences between the positions of play. These two pieces of information show the importance of different forms of analysis.
There were no differences in BMD between soccer players, according to field position, but when the soccer players were compared with the control group there were differences (p= 0.001). Fredericson et al (2007), compared the BMD of soccer players with runners and sedentary men, and noted that soccer players' total BMD only showed a difference with the control group, which is similar to our findings. The highest BMD values found among players can be explained, because soccer is a sport that involves activities and intermittent high intensities, which include sprinting, jumping, accelerations, decelerations and quick changes of direction, which involve the stimulation of acquiring bone mineral (Heinonen, Sievanen, Kyrolainen, Perttunen, & Kannus, 2001; Robling, Hinant, Burr, & Turner, 2002).
The data from the present study provides an insight of the anthropometric characteristics and the body composition of professional soccer players. That said, some limitations should be addressed. The goalkeeper being a position with a smaller number of athletes on the team, the data collection season and not having a diet control group.
The results of this study show that soccer players have specific morphological characteristics related to body composition as compared to a control group. However, only goalkeepers differed as compared to the other player positions.
CONCLUSIONS It is possible to conclude that the Brazilian professional soccer players studied in this study showed significant differences in body composition compared to non-players. According to the field position, goalkeepers and defenders were taller and heavier than the players from the sidelines, the midfield and the attack.
REFERENCES
Arnason, A., Sigurdsson, S. B., Gudmundsson, A., Holme, I., Engebretsen, L., & Bahr, R. (2004). Physical fitness, injuries, and team performance in soccer. Medicine & Science in Sports & Exercise, 36(2), 278-285. doi: 10.1249/01.MSS.0000113478.92945.CA [ Links ]
Carling, C., & Orhant, E. (2010). Variation in body composition in professional soccer players: Interseasonal and intraseasonal changes and the effects of exposure time and player position. Journal of Strength and Conditioning Research, 24(5), 1332-1339. doi: 10.1519/JSC.0b013e3181cc6154 [ Links ]
Casajus, J. A. (2001). Seasonal variation in fitness variables in professional soccer players. Journal of Sports Medicine Physical Fitness, 41(4), 463-469. [ Links ]
Davis, J. A., Brewer, J., & Atkin, D. (1992). Pre-season physiological characteristics of English first and second division soccer players. Journal of Sports Sciences, 10(6), 541-547. doi: 10.1080/02640419208729950 [ Links ]
Franks, A., Williams, A., Reilly, T., & Nevill, A. (1999). Talent identification in elite youth soccer players: Physical and physiological characteristics. Journal of Sports Sciences, 17(10), 812. [ Links ]
Fredericson, M., Chew, K., Ngo, J., Cleek, T., Kiratli, J., & Cobb, K. (2007). Regional bone mineral density in male athletes: A comparison of soccer players, runners and controls. British Journal of Sports Medicine, 41(10), 664-668. [ Links ]
Gissis, I., Papadopoulos, C., Kalapotharakos, V. I., Sotiropoulos, A., Komsis, G., & Manolopoulos, E. (2006). Strength and speed characteristics of elite, subelite, and recreational young soccer players. Research in Sports Medicine, 14(3), 205-214. [ Links ]
]]>Goulding, A., Taylor, R. W., Grant, A. M., Jones, S., Taylor, B. J., & Williams, S. (2009). Relationships of appendicular LMI and total body LMI to bone mass and physical activity levels in a birth cohort of New Zealand five-year olds. Bone, 45(3), 455-459. doi: 10.1016/j.bone.2009.05.007 [ Links ]
Heinonen, A., Sievanen, H., Kyrolainen, H., Perttunen, J., & Kannus, P. (2001). Mineral mass, size, and estimated mechanical strength of triple jumpers' lower limb. Bone, 29(3), 279-285. [ Links ]
Heymsfield, S. B., Wang, Z. M., Visser, M., Gallagher, D., & Pierson, R. N. (1996). Techniques used in the measurement of body composition: An overview with emphasis on bioelectrical impedance analysis. American Journal of Clinical Nutrition, 64(3), S478-S484. [ Links ]
Lohman, T. G., Roche, A. F. & Heymsfield, S. B. (1996). Dual energy x-ray absorptiometry. In A. F. Roche, S. B. Heymsfield & T. G. Lohman (Eds.) Human body composition (63-78). Champaign, Il: Human Kinetics. [ Links ]
Matkovic, B. R., Durakovic, M., Matkovic, B., Jankovic, S., Ruzic, L., Leko, G., & Kondric, M. (2003). Morphological differences of elite Croatian soccer players according to the team position. Collegium Antropologicum, 27(S1), 167-174. [ Links ]
Reilly, T. (1997). Energetics of high-intensity exercise (soccer) with particular reference to fatigue. Journal of Sports Sciences, 15(3), 257-263. doi: 10.1080/026404197367263 [ Links ]
Reilly, T., & Williams, A. M. (Eds.) (2003). Science and soccer. London: Routledge. [ Links ]
Reilly, T., Bangsbo, J., & Franks, A. (2000). Anthropometric and physiological predispositions for elite soccer. Journal of Sports Sciences, 18(9), 669-683. doi: 10.1080/02640410050120050 [ Links ]
Rhodes, E. C., Mosher, R. E., McKenzie, D. C., Franks, I. M., Potts, J. E., & Wenger, H. A. (1986). Physiological profiles of the Canadian Olympic Soccer Team. Canadian Journal of Applied Sport Sciences, 11(1), 31-36. [ Links ]
Rienzi, E., Mazza, J. C., Carter, J. E. L., & Reilly, T. (1998). Futbolista sudamericano de élite: Morfología, análisis del juego y performance: resultados de las investigaciones en composición corporal, análisis del movimiento y análisis táctico, en la Copa América 1995 (Uruguay). Argentina: Editorial Biosystem Servicio Educativo. [ Links ]
Robling, A. G., Hinant, F. M., Burr, D. B., & Turner, C. H. (2002). Shorter, more frequent mechanical loading sessions enhance bone mass. Medicine & Science in Sports & Exercise, 34(2), 196-202. doi: 10.1097/00005768-200202000-00003 [ Links ]
Silvestre, R., West, C., Maresh, C. M., & Kraemer, W. J. (2006). Body composition and physical performance in men's soccer: A study of a National Collegiate Athletic Association Division I team. Journal of Strength and Conditioning Research, 20(1), 177-183. doi: 10.1519/R-17715.1 [ Links ]
Sporis, G., Jukic, I., Ostojic, S. M., & Milanovic, D. (2009). Fitness profiling in soccer: Physical and physiologic characteristics of elite players. Journal of Strength and Conditioning Research, 23(7), 1947-1953. doi: 10.1519/JSC.0b013e3181b3e141 [ Links ]
Sutton, L., Scott, M., Wallace, J., & Reilly, T. (2009). Body composition of English Premier League soccer players: Influence of playing position, international status, and ethnicity. Journal of Sports Sciences, 27(10), 1019-1026. doi: 10.1080/02640410903030305 [ Links ]
Acknowledgments:
Nothing to declare.
Conflicts of Interest:
Nothing to declare.
Funding:
Nothing to declare.
Manuscript received February 27, 2014; Revised April 21, 2014; Accepted April 25, 2014
]]>
*Corresponding author: Departamento de Educação Física, Universidade Estadual Paulista (UNESP), Rua Roberto Simonsen, nº 305 – Centro Educacional, Presidente Prudente, CEP 19060-900 São Paulo, Brasil; E-mail: netoef@yahoo.com.br
]]>
