Effects of small-sided games on the haematological profile of soccer players

• Published in: Journal of Physical Education and Sport Vol. 21; no. 4; pp. 1860 - 1870
• Main Authors: Mitrotasios, Michail, Souglis, Athanasios, Ispyrlidis, Ioannis, Giodldasis, Aristotelis, Mantzouranis, Konstantinos, Isaakidis, Alexandros, Andronikos, Georgios
• Format: Journal Article
• Language: English
• Published: Pitesti Universitatea din Pitesti 01.06.2021
• Subjects: Blood; Blood platelets; Exercise; Hematology; Hemoglobin; Iron; Physiology; Scientific Concepts; Soccer; Team Sports; Training Methods
• ISSN: 2247-8051; 2247-806X
• DOI: 10.7752/jpes.2021.04235

The aim of this study was to examine the changes in blood parameters caused during Small-Sides Games (SSGs) in U20 elite players in professional league. The sample consisted of eight U20 Greek Super League elite level soccer players, aged 18.3 ± 1 years old, who participated in six SSG's (4 vs 4 + 2 GK), each lasting 4 min with 3 min rest. The size of the pitch was 30m in length and 20m wide and the SSGs took place in a pitch with artificial turf. Blood samples were collected before and immediately after the six SSGs to examine any potential changes of the haematological profile and the levels of cell damage. The Wilcoxon Test (Z) and the Effect Size (r) were used to compare the repeated measures of the variables (pre-post), while the Pearson correlation index (r) was used to test the correlation between the variables. The results showed a significant decrease in the second measurement in Rbc (p < .05), Hgb (p < .05), Mcv (p < .01), Mch (p < .05) and Mchc (p < .05). On the contrary, Hct, Rdw and iron concentration did not show a significant change (p > .05). Regarding the elements of the leukocyte series a significant increase was observed in Wbc (p < .01), Neutrophils (p < .05), Plt (p < .05), and Pct (p < .01). On the contrary, a significant decrease was observed in Lymphocytes (p < .05) and Pdw (p < .05). Finally, Monocytes, Eosinophils and Pct did not show any statistically significant change. Overall, the results showed that exercising through high intensity SSGs can cause specific metabolic effects on the haematological profile of soccer players. Soccer teams need to incorporate the monitoring of haematological parameters of players while planning their training program, as this information can influence the performance and overall wellbeing of players.