Effect of SMIT compound exercises on IL-6 and IL-15 proteins and football performance endurance in young players

Abstract

Abstract

This study addresses several key areas, including the introduction and significance of the research. Despite the importance and widespread use of the SMIT method, studies investigating its impact on muscle cytokines, particularly IL-6 and IL-15, in young football players are scarce, especially regarding their relationship to improved endurance. Furthermore, the relationship between reduced muscle inflammation and improved football performance endurance in this age group remains insufficiently clear, particularly given the differences in the nature of the response between IL-6 and IL-15. Hence, the importance of this research lies in its aim to fill a significant knowledge gap by analyzing the effect of combined SMIT exercises on muscle cytokines and performance endurance in young football players, thereby contributing to enhanced training decisions for specialized coaches.

The research problem lies in the fact that, despite significant advancements in physical training methods, those responsible for the training process still need a broader understanding of the profound physiological changes that occur at the level of muscle cytokines during high-intensity training programs. Elevated IL-6 is a marker of acute muscle stress, but it can also increase with glycogen deficiency or impaired muscle recovery. IL-15, on the other hand, may be associated with increased muscle growth, but it also rises as a compensatory response to muscle fiber damage.

The problem is that, despite significant advancements in physical training methods, those involved in the training process still need a broader understanding of the profound physiological changes that occur at the level of muscle cytokines during high-intensity training programs. This prompted the researchers to study this problem. Despite the widespread use of high-intensity training methods, research addressing the direct effect of the SMIT method on cytokines in young football players is almost nonexistent, especially concerning their relationship to performance endurance. Hence, the research problem arises in the following question: Does the use of combined exercises using the SMIT method have a positive effect on the proteins IL-6 and IL-15 and on football performance endurance in young players? The research aimed to: determine the effect of combined exercises using the SMIT method on the proteins IL-6 and IL-15 and on football performance endurance in young players; and identify the superior effect between combined exercises using the SMIT method and exercises prescribed by the coach on the proteins IL-6 and IL-15 and on football performance endurance in young players.

As for the third section, the researchers used the applied method. The research population was defined as the youth players of Naft Al-Wasat Sports Club for the (2025-2026) sports season, totaling (30) players. The researchers selected (6) players to represent the pilot study from the same population, constituting (20%) of the research population. The researcher then selected the main experimental sample of (20) players. The selection of the research sample was done using simple random methods (drawing lots), and it constituted (66.66%) of the research population. The researchers excluded (4) goalkeepers, who constituted (13.13%), because the research requirements did not match their capabilities. Regarding the most important conclusions and recommendations, the most significant conclusions were: SMIT compound exercises demonstrated a clear effectiveness in reducing levels of interleukin-6 (IL-6) protein, indicating a decrease in inflammatory burden and an improved physiological response to exertion. Furthermore, IL-15 protein levels showed a significant increase after the application of SMIT compound exercises, reflecting increased activity in muscle-building pathways and improved functional endurance.

The most important recommendations included: adopting SMIT compound exercises as a primary training method for young football players to simultaneously improve aerobic and anaerobic capacity, as well as conducting periodic cytokine (IL-6, IL-15) tests to monitor physiological changes in players and ensure they do not exceed undesirable stress levels.