Maturational effect on physical capacities and anabolic hormones in under-16 elite footballers: a cross-sectional study

Ebrahim Eskandarifard,Rui Silva,António José Figueiredo,Filipe Manuel Clemente,Jorge Pérez-Gómez,Hadi Nobari

doi:10.1007/s11332-021-00806-y

Abstract

PurposeThe purposes of this study were to describe the fitness and hormonal levels according to playing time (PT) (i.e., PT during season less (PT1) or more (PT2) than 50% of the total time) and maturation level (ML) (i.e., normal (ML1) and early maturity levels (ML2)), and to analyze the differences between groups for the measures of aerobic capacity, anaerobic power, power performance, and hormonal concentrations.MethodsTwenty-four youth footballers of a U16 team participated in this study. Anthropometric measures, maturity status, growth hormone, insulin-like growth factor (IGF-1), maximal oxygen uptake, fatigue index, and countermovement jump were collected.ResultsSignificant differences were found between both PT and ML groups for maturational status, aerobic capacity, power performance, and IGF1 concentrations. The interaction of PT and ML revealed significant differences for maturity offset and power performance. When using the skeletal age as a covariant, the previously significant differences found were reduced only to the fatigue index measure.ConclusionsThe response variables analyzed in the present study seem to be influenced by PT and ML. This must be considered when planning training, and coaches must be sensible to these effects as they may assume a preponderant role in PT.

Highlights

Football has evolved into a more physically, technical, and tactical demanding sport over the past few years [1]
We summarized some variables like total season playing time: 1383.4 ± 260.7 min; height: 176.4 ± 5.3 cm; VO2max: 49.5 ± 3.5 ml.kg−1.min−1; IGF-1 level: 392.0 ± 107.7 ng/dl; skeletal age: 16.6 ± 0.8, that was used to divided players in the two groups
Significant differences between PT1 and PT2 were found for minutes of playing (F = 45.1, p < 0.01, ƞp2 = 0.7), age at peak height velocity (PHV) (F = 8.1, p < 0.01, ƞp2 = 0.3), maturity offset (F = 11.2, p < 0.01, ƞp2 = 0.4), standing height (F = 6.0, p < 0.01, ƞp2 = 0.2), sitting height (F = 8.5, p < 0.01, ƞp2 = 0.3), VO2max (F = 9.8, p < 0.01, ƞp2 = 0.3), countermovement jump (CMJ) (F = 9.2, p < 0.01, ƞp2 = 0.3) and IGF-1 level (F = 17.0, p < 0.01, ƞp2 = 0.5)

Summary

Introduction

Football (soccer) has evolved into a more physically, technical, and tactical demanding sport over the past few years [1]. This fact has been corroborated by studies using data collected via modern devices, such as global positioning systems, enabling to reveal that elite football teams are dealing with greater match demands [2]. As such, this information can be used by coaches and scouts for talent identification and player selection [3].

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Discussion

Conclusion