Variations in important aerobic fitness parameters and physical characteristics during two consecutive preseason periods in adolescent soccer players

Abstract

Purpose. This study examined the variations in selected aerobic fitness parameters, namely maximum oxygen consumption (VO2max), running velocity at VO2max (vVO2max), running velocity at ventilatory threshold (vAnT) and 1-minute post-exercise heart rate recovery (%HRrec) as well as height, body mass and percentage of body fat (%BF) in high-level adolescent soccer players. The relationship between %BF and VO2max values was also analyzed. Methods. 25 athletes (mean age: 14.5 ± 1.3 years) were measured at the second week of the preseason period (1st period) and at the same corresponding week after a 12-month period (2nd period). Results. VO2max, vVO2max and vAnT increased significantly by 6.6, 6.5 and 3.27%, respectively, from the 1st to 2nd period (p 0.01 - 0.05; effect size (ES) = -0.35 - 0.66). In contrast, %HRrec remained relatively unchanged (-0.5%) during the same period (p > 0.05; effect size (ES) = 0.01). %BF showed a negative trend, but no significant correlation with VO2max was found during the same period (r = -0.331; p > 0.05). Significant variations were found for height and body mass (2.64 and 11.17%; p ≤0.01; effect size (ES) = -0.56 and -0.72, respectively), but not for %BF (1.34%; p > 0.05; effect size (ES) = -0.27). Conclusions. This data can provide useful information regarding physiological aerobic adaptations and changes in physical characteristics as a result of a year of soccer training, including growth and maturations processes, during the specific periods tested.