The influence of maturation, fitness, and hormonal indices on minutes played in elite youth soccer players: a cross-sectional study.

BACKGROUND: The main purpose of this study was to investigate the relationships between minutes played (MP) with maturity status, fitness, and hormonal levels, and to quantify their influence on minutes played. METHODS: Twenty-four elite youth soccer players under-16 years participated in this study, over a full-season period. Anthropometric measures, maturity status, hormonal and physical fitness levels were collected. Participants were monitored during the season. After the end-season, players were assessed in 6 different tests over a four-day period. RESULTS: The maximum oxygen consumption (V̇O2max) was strongly correlated with MP (r = 0.75), maturity offset (r = 0.52), and countermovement jump (r = 0.53). Multiple linear regression explained 76% of MP (F (8, 15) = 6.05, p = 0.001), with an R2 of 0.76. Moreover, Growth hormone (GH) and V̇O2max. were the most influential factors in MP (F (2, 21) = 17.92, p ≤ 0.001), with an R2 of 0.63. CONCLUSION: High levels of GH and V̇O2max have a preponderant role in MP by elite youth soccer players, it appears to be more pragmatic to consider other contextual dimensions, as they can impact selection for competition and minutes of participation in a match.

Associations between match participation, maturation, physical fitness, and hormonal levels in elite male soccer player U15: a prospective study with observational cohort.

OBJECTIVES: The aims of this study were to analyze the relationships between minutes of play (MP) and maturity status, fitness, and hormonal levels and to explain how those measures influence the time of play. METHODS: Twenty-six youth soccer players U15 participated in this study over a full-season period. Anthropometric measures, maturity status, growth hormone (GH), insulin-like growth factor and physical levels such as maximal oxygen uptake (VO2max), fatigue index, countermovement jump (CMJ) performance were collected. At the end-season, players were assessed in 6 different tests over four days. RESULTS: VO2max largely correlated with GH (r = 0.57) and CMJ (r = 0.51). Also, GH largely correlated with CMJ (r = 0.55). MP had moderate correlations with VO2max (r = 0.44) and CMJ (r = 0.42). Multiple linear regression with maturation, physical fitness and hormonal levels explained R2 of 0.62 of the MP (F (8, 17) = 3.47, p = 0.015). Although each independent variable alone was not able to determine the playing time, when using the interactions, the model significantly explained the MP. CONCLUSIONS: The combination of maturity status, physical fitness, and hormonal levels seem to play a determinant role in explaining the match participation in youth soccer players.

Exploring interactions between maturity status and playing time with fluctuations in physical fitness and hormonal markers in youth soccer players.

The purpose of this study was to determine the differences in functional capacities and hormonal indices according to biological maturity and seasonal playing time status in young soccer players. Twenty-three male under-15 players (14.6 ± 0.2 years) were divided into two groups, based on their maturity status and seasonal playing time. They were measured for anthropometrics, Yo-Yo intermittent recovery level 1 (YYIR1), seven repeated sprint test (7RST), countermovement jump (CMJ), skeletal age, growth hormone, and insulin-like growth factor-1 (IGF-1) level. Age at peak height velocity (APHV) was determined to estimate the maturity timing. The results revealed that players who advanced in maturation were significantly heavier (p = 0.029) and had higher values in skeletal age (p < 0.001), sitting height (p = 0.005), CMJ (p = 0.038), and IGF-1 (p = 0.013). Players given greater playing time exhibited significantly lower fatigue index (p = 0.012), but higher CMJ (p = 0.003) and IGF-1 (p = 0.001) values. The overall results highlighted that early-maturing players and players with greater playing time obtained higher values in both CMJ and IGF-1. The findings may provide an insight on the coaches' evaluation of players and on the possible factors that may affect the future playing status of young male soccer players.