Saturday, 29 June 2013

ECSS BARCELONA 2013

Yesterday, we were presenting an oral communication in Barcelona (Spain) in the 18th annual Congress of the European College of Sport Science. The abstract of the communication can be found in the ECSS Congress Search Engine clicking here. Also, if you prefer, you can read it afterwards:

BODY COMPOSITION IN TENNIS PLAYERS AND MAXIMAL OXYGEN INTAKE: A LONGITUDINAL STUDY WITH CHILDREN

Rey-López, JP.1, Berdejo-del-Fresno D.2, Santín-Medeiros F.3, Moraes, AC.1, Barbosa de Carvalho, H.1
 
1: Faculty of Medicine USP (Sao Paulo, Brasil), 2: The Football Association (England), 3: INEF (León, Spain).

Introduction
Tennis is an anaerobic predominant activity requiring high levels of aerobic conditioning to avoid fatigue and aid in recovery between points. Body composition is often measured in  young tennis players but it is unclear if it is a useful predictor of a better cardiorespiratory fitness. The aim of this study is to examine the association between: I) Anthropometric measures and maximal oxygen intake (VO2max); II) Dual x- ray absorptiometry (DXA) and VO2max.

Methods
7 children (3 boys and 4 girls, age = 10.83 ± 0.39) from the high-performance tennis center from the Aragon Tennis Federation (Spain) were measured twice during a whole season (baseline-10 months later) (Berdejo-del-Fresno et al. 2010). Body composition (whole lean, bone and fat mass) by DXA (Explorer, Hologic Corp.) and by anthropometry (height, weight, waist circumference). VO2max was estimated by Leger et al. (1984) using the 20 meter shuttle run test. A linear regression analysis was performed (adjusting by age) between baseline body composition and VO2max at the end of the season. A significance level was considered when p values were <0.05. Statistical analyses were performed using STATA 12.1.

Results
No significant mean differences in VO2max (ml/kg/min) were found during the season (baseline: 54±3, 10months: 55±3). In the regression model, body composition at baseline by DXA was not statistically associated with VO2max values at the end of the season: Standardized β (95% CI): 0.56 (-0.28-1.19); -0.55 (-1.02-0.24); 0.46 (-1.60-9.24) for lean mass, fat mass and bone mass respectively. Similarly, anthropometric measurements were no associated with VO2max values. β (95% CI): -0.27 (-0.67-0.28); -0.34 (-63,4-25,7); -0.05 (-0.60-0.57) for weight, height and waist circumference respectively.

Discussion
Our results show that in children who regularly train for competitive reasons (our sample around 12 hours per week) body composition is not a predictor of VO2max changes during a whole season. Therefore, we suggest that in pubescent tennis players changes in VO2max are more likely due to hematological variables (Hemoglobin, Hematocrit changes) as has been found in soccer players (Hansen et al. 2004). In summary, in competitive tennis children players’ body composition analyses are not justified as a way to predict aerobic performance. Nonetheless, the study of body composition in athletes by DXA should be promoted to monitor changes in bone mass during growing years.

References
1)  Berdejo-del-Fresno D, Vicente-Rodríguez G, González-Ravé JM, Moreno LA, Rey-López JP. (2010). J Hum Sport Exerc, 5, 250-264.
2)      Leger L, Lambert J, Goulet A, Rowan C, Dinelle Y. (1984) Can J Appl Sport Sci, 9, 64-69.
3)      Hansen L, Klausen K. (2004) J Sports Med Phys Fitness. 44:219-223.

If you wish to know more about body composition and fitness level in young tennis players you can read my MPhil in Sport Performance dissertation: “Anthropometric and physical condition changes in season for talented tennis players” that was published in the book:

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