ArticlePloS one2019
Effects of a six-week period of congested match play on plasma volume variations, hematological parameters, training workload and physical fitness in elite soccer players.
Article in PloS one, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers, 5 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
25 citing papers in PubMed, 5 syntheses or guidelines pooled it.
- The Correlations Between Training Load Parameters and Physical Performance Adaptations in Team Sports: A Systematic Review and Meta-analysis.Sports medicine - open · 2025Pooled it
- Assessment of Aerobic Fitness and Repeated Sprint Ability in Elite Male Soccer: A Systematic Review of Test Protocols Used in Practice and Research.Sports medicine (Auckland, N.Z.) · 2025Pooled it
- Assessment of Strength and Power Capacities in Elite Male Soccer: A Systematic Review of Test Protocols Used in Practice and Research.Sports medicine (Auckland, N.Z.) · 2024Pooled it
- Hematology, Hormones, Inflammation, and Muscle Damage in Elite and Professional Soccer Players: A Systematic Review with Implications for Exercise.Sports medicine (Auckland, N.Z.) · 2021Pooled it
- Load Measures in Training/Match Monitoring in Soccer: A Systematic Review.International journal of environmental research and public health · 2021Pooled it
- Recovery kinetics following matches in congested vs. non-congested schedules: effects on pressure pain sensitivity, delayed onset muscle soreness, and muscular performance in soccer players.BMC sports science, medicine & rehabilitation · 2026Article
- A Randomized Controlled Trial Comparing High- and Moderate-Intensity Interval Walking on Hematological and Functional Markers in Postmenopausal Women with Obesity.Sports (Basel, Switzerland) · 2026Article
- How intense is high-intensity interval training? Biomarker responses and associations with training load and fitness.iScience · 2025Article
- The International Match Calendar in Men's Professional Football: An Expert Position Statement.Scandinavian journal of medicine & science in sports · 2025Article
- Hematological, Biochemical, and Performance Adaptations in Amateur Soccer Players Following a 4-Week Preseason Training Period.Journal of functional morphology and kinesiology · 2025Article
- Antioxidant Defense and Redox Signaling in Elite Soccer Players: Insights into Muscle Function, Recovery, and Training Adaptations.Antioxidants (Basel, Switzerland) · 2025Review
- Seasonal Changes in Performance Metrics, Hormonal, Hematological, and Biochemical Markers Among Semi-Professional Soccer Players: Implications for Training and Recovery.Journal of functional morphology and kinesiology · 2025Article
- The Effects of Combined Versus Single-Mode Resistance and Repeated Sprint Training on Physical Fitness, Hematological Parameters, and Plasma Volume Variations in Highly Trained Soccer Players.Sports (Basel, Switzerland) · 2024Article
- Does Total Playing Time Affect the Neuromuscular, Physiological, and Subjective Recovery of Futsal Players during a Congested Period?Sports (Basel, Switzerland) · 2024Article
- Can the supplementation of vitamin D, sun exposure, and isolation during the COVID-19 pandemic affect the seasonal concentration of 25(OH)D and selected blood parameters among young soccer players in a one-year training season?Journal of the International Society of Sports Nutrition · 2023Article
- The Effect of Environmental Disasters on Endocrine Status, Hematology Parameters, Body Composition, and Physical Performance in Young Soccer Players: A Case Study of the Aral Sea Region.Life (Basel, Switzerland) · 2023Article
- Article
- Innate immunity changes in soccer players after whole-body cryotherapy.BMC sports science, medicine & rehabilitation · 2022Article
- Daily and weekly external loads in the microcycle: Characterization and comparison between playing positions on amateur soccer.Frontiers in sports and active living · 2022Article
- Relationships between Fitness Status and Blood Biomarkers in Professional Soccer Players.Journal of healthcare engineering · 2022Article
Corrections and comments
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Authors and funding
10 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesThe aims of this study were to investigate the effects of a six-week in-season period of soccer training and games (congested period) on plasma volume variations (PV), hematological parameters, and physical fitness in elite players. In addition, we analyzed relationships between training load, hematological parameters and players' physical fitness.
methodsEighteen elite players were evaluated before (T1) and after (T2) a six-week in-season period interspersed with 10 soccer matches. At T1 and T2, players performed the Yo-Yo intermittent recovery test level 1 (YYIR1), the repeated shuttle sprint ability test (RSSA), the countermovement jump test (CMJ), and the squat jump test (SJ). In addition, PV and hematological parameters (erythrocytes [M/mm3], hematocrit [%], hemoglobin [g/dl], mean corpuscular volume [fl], mean corpuscular hemoglobin content [pg], and mean hemoglobin concentration [%]) were assessed. Daily ratings of perceived exertion (RPE) were monitored in order to quantify the internal training load.
resultsFrom T1 to T2, significant performance declines were found for the YYIR1 (p<0.001, effect size [ES] = 0.5), RSSA (p<0.01, ES = 0.6) and SJ tests (p< 0.046, ES = 0.7). However, no significant changes were found for the CMJ (p = 0.86, ES = 0.1). Post-exercise, RSSA blood lactate (p<0.012, ES = 0.2) and PV (p<0.01, ES = 0.7) increased significantly from T1 to T2. A significant decrease was found from T1 to T2 for the erythrocyte value (p<0.002, ES = 0.5) and the hemoglobin concentration (p<0.018, ES = 0.8). The hematocrit percentage rate was also significantly lower (p<0.001, ES = 0.6) at T2. The mean corpuscular volume, mean corpuscular hemoglobin content and the mean hemoglobin content values were not statistically different from T1 to T2. No significant relationships were detected between training load parameters and percentage changes of hematological parameters. However, a significant relationship was observed between training load and changes in RSSA performance (r = -0.60; p<0.003).
conclusionsAn intensive period of "congested match play" over 6 weeks significantly compromised players' physical fitness. These changes were not related to hematological parameters, even though significant alterations were detected for selected measures.
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