Table 1. Baseline characteristics of participants (mean ± SD). Variable SAND (n = 14) GRASS (n = 14) CON (n = 14) Age (years) 20.1 ± 1.6 19.6 ± 1.4 19.8 ± 1.3 Height (cm) 177.1 ± 3.6 177.9 ± 5.6 175.1 ± 3.4 Body mass (kg) 73.9 ± 5.2 74.0 ± 5.1 73.5 ± 3.4 Training experience (years) 9.6 ± 1.2 9.4 ± 1.1 9.6 ± 1.1 Playing position (F/M/D) 5 / 4 / 5 5 / 4 / 5 5 / 4 / 5 CON, control; F/M/D, forwards/midfielders/defenders.