Associations Between Variations in Accumulated Workload and Physiological Variables in Young Male Soccer Players Over the Course of a Season

Abstract

This study sought to analyze the relationship between in-season training workload with changes in aerobic power (VO2max), maximum and resting heart rate (HRmax and HRrest), linear sprint medium (LSM), and short test (LSS), in soccer players younger than 16 years (under-16 soccer players). We additionally aimed to explain changes in fitness levels during the in-season through regression models, considering accumulated load, baseline levels, and peak height velocity (PHV) as predictors. Twenty-three male sub-elite soccer players aged 15.5 ± 0.2 years (PHV: 13.6 ± 0.4 years; body height: 172.7 ± 4.2 cm; body mass: 61.3 ± 5.6 kg; body fat: 13.7% ± 3.9%; VO2max: 48.4 ± 2.6 mL⋅kg–1⋅min–1), were tested three times across the season (i.e., early-season (EaS), mid-season (MiS), and end-season (EnS) for VO2max, HRmax, LSM, and LSS. Aerobic and speed variables gradually improved over the season and had a strong association with PHV. Moreover, the HRmax demonstrated improvements from EaS to EnS; however, this was more evident in the intermediate period (from EaS to MiS) and had a strong association with VO2max. Regression analysis showed significant predictions for VO2max [F(2,20) = 8.18, p ≤ 0.001] with an R2 of 0.45. In conclusion, the meaningful variation of youth players’ fitness levels can be observed across the season, and such changes can be partially explained by the load imposed.

Variations of Training Workload in Micro- and Meso-Cycles Based on Position in Elite Young Soccer Players: A Competition Season Study

“…Recent literature has discussed the effects of training and matches on wellness indicators mainly in professional ( Clemente et al, 2017 ; Costa et al, 2018 ), collegiate soccer players ( Rabbani et al, 2018 ), physiological variables ( Nobari et al, 2021a ), and fitness status variations ( Nobari et al, 2021d ). In general, well-being ratings were sensitive to assessing the impact of congested fixture ( Clemente et al, 2017 ; Rabbani et al, 2018 ), Ramadan fasting ( Chamari et al, 2012 ), and match-induced fatigue ( Rabbani et al, 2019 ), but not to the effects of late-night training with low perceived load ( Costa et al, 2018 ).…”

“…All anthropometric measurements, body composition, calculation of body fat percentage, and how to calculate maturity offset and age at peak velocity have been performed based on the methods of previous studies ( Nobari et al, 2020e , 2021a , c , d ). All measurements were performed by an expert with 5 years of experience in the field ( Arazi et al, 2015 ; Rahmat et al, 2016 ).…”

Somatotype, Accumulated Workload, and Fitness Parameters in Elite Youth Players: Associations with Playing Position

“…To the question “How intense was your session?” players answered in the interval of number zero for the day without training, 1 for minimum effort and 10 for maximal effort. Players provided responses 30 min after the end of the training session [ 12 , 34 ]. Additionally, the duration of the training sessions (in minutes) was recorded for each player.…”

“…This is the physiological index most widely used for measuring aerobic fitness of soccer players and can be determined in both, laboratory and field tests. It helps to clarify the level of physical fitness and if it is high, it probably prevents or reduces the risk of injury [ 12 , 13 , 14 ].…”

Exploring the Determinants of Repeated-Sprint Ability in Adult Women Soccer Players

“…On the other hand, vertical jump decreased over the season, possibly due to the lack of reactive strength training or oriented training for this physical quality. Usually, both RSA and aerobic performance are key determinants of physical performance in soccer and match running-performance is associated with those capacities [ 16 , 46 , 47 ], thus it can be expected that over the season the training and match load may explain positive changes in RSA and aerobic performance [ 48 , 49 ].…”