Body Comparison Before And Agyer Six Weeks Preseasone Training In Professional Football Players

Introduction
The relative amount of lean and fat mass is an important factor in predisposition for physical performance in games
players. Recent technological advances have enhanced accuracy and precision in the measurement of body
composition. The emergence of dual energy x-ray absorptiometry (DEXA) as a body composition tool has promoted
much interest in the field of anthropometry due to its unique ability to subdivide the body into bone mineral mass, fat
mass and fat free mass components. Additionally, it overcomes the population specific nature of equations for
predicting body fat from anthropometric measures, and the assumptions of constant fat free tissue density associated
with hydrodensitometry. However, DEXA is not a suitable measurement for ‘field’ testing and its relative
unavailability means that it is still not a popular tool among sport science support staff. The aim of this study was to
determine changes in body fat, muscle mass and bone density measurements over 6 weeks of preseason training in
professional football players and to compare body fat percentages derived from skinfold measurements and from
DEXA whole-body measurements.

Methods
Body composition (body fat, total body bone mineral density and muscle mass) data were measured in 13 professional
English Premier League football players (age: 26.3 ± 5.0 years; mass: 85.0 ± 6.6 kg; height: 1.84 ± 0.05 m) at the
beginning of preseason training using DEXA whole body measurements. Measurements were repeated for these players
following 6 weeks of preseason training. Percent body fat was also estimated using skinfold methods (1) at this time.
DEXA and skinfold measures were taken for an additional 3 players at one time point only.

Results
Following 6 weeks preseason training, percent body fat measurements, as measured by DEXA, were reduced in all
players, a significant (P<0.001) mean change of 2.0% body fat. Actual body fat values were reduced by 2.0 kg. Whole
body bone mineral density values showed a significant increase over the preseason training period (p<0.01). Increases
in lean mass were not significant (P>0.1). Body fat estimates for DEXA and skinfold methods were highly correlated
(r=0.89, p<0.001).

Discussion/Conclusions
The British Olympic Association (2) recommend using anthropometric skinfold measures in the absence of access to
DEXA or hydrostatic weighing facilities The high correlation between DEXA and skinfold estimates, suggests that
despite apprehensions about this method of measuring adiposity (3), it does appear to be a suitable tool in the field
setting. Additionally DEXA appears sensitive enough to detect body fat changes over 6 weeks training.

References
[1]. Durnin J. & WomersleyJ. (1974) British Journal of Nutrition, 32, 77-97
[2]. Reilly T. et al. (1996) Sports Exercise and Injury, 2, 46-49
[3]. Clarys JP. et al. (1987) Journal of Sports Sciences, 5, 3-33

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