The goal of this study is to investigate the effects of varying friendly match-play exposure during the late pre-season on physiological, biochemical, and performance adaptations in soccer players. It is hypothesized that (i) significant changes will occur across the pre-season in both the extended- and limited-play groups when analysed independently; (ii) distinct group-specific adaptations will emerge by the end of the preparatory period; and (iii) match-play exposure, when analysed across all participants, will be significantly correlated with physiological and performance outcomes at pre-season completion. Players from a randomly selected team will be assessed at three time points: pre-season start, mid-pre-season (MPS), and pre-competition phase (PC). Assessments will include anthropometry, physical performance, and markers of muscle damage, inflammation, hormonal status, and haematology. Based on the total match-play time of 8 friendly games during the late pre-season, players will be retrospectively categorised into extended-play (EP) and limited-play (LP) cohorts.time of 8 friendly games during the late pre-season, players will be retrospectively categorised into extended-play (EP) and limited-play (LP) cohorts.
Study Type
OBSERVATIONAL
Enrollment
24
This research explores the multidimensional physiological and biochemical responses to differing volumes of friendly match-play (i.e., extended vs. limited) during the late pre-season phase in soccer players.
School of Physical Education and Sports Science, National and Kapodistrian University of Athens
Athens, Daphni, Greece
Body Mass
Description: Body mass measured at standard anatomical sites using a calibrated scale to track longitudinal changes over the pre-season. Unit of Measure: kg
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Body Fat
Description: Body fat percentage measured using skinfold calipers at standard sites to monitor longitudinal changes. Unit of Measure: %
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Rate of Perceived Exertion (RPE)
Description: Participants rate exertion during standardized training sessions using the Borg Scale (6 = no exertion, 20 = maximal exertion). Unit of Measure: Borg 6-20 scale
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Glucose
Description: Fasting blood glucose measured to track metabolic changes over pre-season. Unit of Measure: mg/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Cholesterol
Description: Total serum cholesterol measured to assess lipid profile adaptations. Unit of Measure: mg/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Triglycerides
Description: Serum triglycerides measured to monitor metabolic response to training. Unit of Measure: mg/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
SGOT (AST)
Description: Serum glutamic-oxaloacetic transaminase measured to assess liver/muscle stress. Unit of Measure: U/L
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
SGPT (ALT)
Description: Serum glutamic-pyruvic transaminase measured to monitor liver/muscle stress. Unit of Measure: U/L
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Creatine Phosphokinase (CPK)
Description: CPK measured to detect skeletal muscle damage. Unit of Measure: U/L
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Myoglobin
Description: Myoglobin measured as a marker of muscle damage. Unit of Measure: ng/mL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Iron
Description: Serum iron measured to assess iron status. Unit of Measure: µg/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Ferritin
Description: Serum ferritin measured to monitor iron storage. Unit of Measure: ng/mL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
C-Reactive Protein (CRP)
Description: CRP measured as a marker of systemic inflammation. Unit of Measure: mg/L
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
High-sensitivity CRP (hs-CRP)
Description: hs-CRP measured to detect low-grade inflammation. Unit of Measure: mg/L
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Interleukin-6 (IL-6)
Description: IL-6 measured from serum to assess inflammatory response. Unit of Measure: pg/mL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Tumor Necrosis Factor-alpha (TNF-α)
Description: TNF-α measured as a marker of systemic inflammation. Unit of Measure: pg/mL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Testosterone
Description: Serum testosterone measured to assess hormonal adaptations. Unit of Measure: ng/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Cortisol
Description: Serum cortisol measured to monitor stress response. Unit of Measure: µg/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Testosterone-Cortisol Ratio
Description: Calculated ratio to estimate anabolic-catabolic balance. Unit of Measure: Ratio
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Red Blood Cells (RBC)
Description: RBC count measured from blood to assess oxygen transport capacity. Unit of Measure: million cells/µL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Hemoglobin
Description: Hemoglobin measured to evaluate oxygen-carrying capacity. Unit of Measure: g/dL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Hematocrit
Description: Hematocrit measured as percentage of RBC in blood. Unit of Measure: %
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
White Blood Cells (WBC)
Description: WBC count measured to monitor immune function. Unit of Measure: cells/µL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Platelets
Description: Platelet count measured to assess hematological health. Unit of Measure: cells/µL
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Countermovement Jump Height
Description: Jump height measured (cm) to assess lower-limb explosive power. Unit of Measure: cm
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Knee Extensor Power, Dominant Leg
Description: Measured using isokinetic dynamometer. Unit of Measure: Watts
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Knee Extensor Power, Non-Dominant Leg
Description: Measured using isokinetic dynamometer. Unit of Measure: Watts
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Knee Flexor Power, Dominant Leg
Description: Measured using isokinetic dynamometer. Unit of Measure: Watts
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
Knee Flexor Power, Non-Dominant Leg
Description: Measured using isokinetic dynamometer. Unit of Measure: Watts
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
10-m Sprint Time
Description: Sprint time measured using photocell gates; lower times indicate better performance. Unit of Measure: seconds
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
T-Test Agility
Description: Participants perform T-test agility course; lower times indicate better agility. Unit of Measure: seconds
Time frame: Each measure assessed at Baseline (pre-season start), 4 weeks (mid-pre-season), and 8 weeks (pre-competition phase).
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