Seasonal Changes in Multiple Indices of Body Composition in Professional Football Players

We examined the seasonal variability of indicators of adiposity and generic and population-specific equations of estimating body fat in professional football players. Anthropometric data of 35 outfield players (age, 20 +/- 4 years; stature, 1.82 +/- 0.06 m; body mass 77.1 +/- 7.3 kg) were collected over a playing season. There were a significant main effects for time for all indicators (p < 0.001). Post hoc analysis revealed significant changes in body composition between July and mid-August (Sigma 4(SF-DW) : 1.6 mm, p < 0.001; Sigma 4(SF-R): 2.4 mm, p = 0.002; Sigma 5(SF): 2.0 mm, p < 0.002; Sigma 8(SF): 3.8 mm, p = 0.001; Reilly et al.: 0.4 %, p = 0.001; Durnin and Wormsley: 0.7 %, p < 0.001). Although all indicators were sensitive to detect small changes in body composition between training mesocycles, we advocate the use of the sum of 4 skinfolds by Reilly et al. to monitor changes in body composition in professional football players; if an estimate of percent body fat is required, the population-specific equation by Reilly et al. may be utilised.