Journal of Eexercise & Organ Cross Talk
Document Type : Original Article
Authors
1 Department of Physical Education and Sport Sciences, SR.C, Islamic Azad University, Tehran, Iran.
2 Department of Exercise Physiology, VaP.C., Islamic Azad University, Varamin, Iran.
What is already known on this subject?
Existing evidence indicates that exercise training can modulate circulating IGF-1, although the direction of this response is highly dependent on training modality, intensity, duration, and the baseline characteristics of the population. Furthermore, the endogenous antioxidant enzyme GPX is known to be responsive to physical activity; however, its upregulation appears to be exercise-mode specific, with traditional resistance training yielding more consistent effects than high-intensity or high-volume protocols. Despite the widespread popularity of metabolic conditioning as a training strategy designed to optimize energy system utilization, its specific effects on hormonal and antioxidant biomarkers remain poorly characterized in the scientific literature, representing a significant gap in knowledge.
What this study adds?
The present study provides the first controlled experimental evidence specifically examining the concurrent effects of a progressive six-week metabolic conditioning program on both IGF-1 and GPX in physically active young adults. Our findings underscore that, based on the primary between-group comparisons, six weeks of metabolic conditioning does not induce significant changes in these biomarkers relative to a control condition. We contribute a nuanced observation: although a secondary within-group reduction in IGF-1 was observed following the intervention, this effect was not statistically superior to the control group after adjusting for baseline values, suggesting that the within-group change may reflect baseline variability rather than a genuine training adaptation. Importantly, the absence of any significant change in serum GPX levels highlights that six weeks of metabolic conditioning, as prescribed in this protocol, may not constitute a sufficient stimulus to trigger measurable antioxidant enzyme adaptations. This underscores the necessity for longer intervention periods and more comprehensive biochemical assessments to fully elucidate the physiological impacts of this training modality.
Keywords
Acknowledgements
None
Funding
None.
Data availability
The data that support the findings of this study are available from the corresponding author upon reasonable request.
Compliance with ethical standards
Conflict of interest the authors declare that there is no conflict of interest in the present research.
Ethical approval All procedures performed in this study involving human participants were in accordance with the ethical standards of the institutional research committee and with the 1964 Helsinki Declaration and its later amendments. The study was approved by the Ethical Committee of Islamic Azad University, Tehran, Iran (approval code: IR.IAU,SRB.REC.1404.365).
Informed consent Written informed consent was obtained from all individual participants included in the study after a full explanation of the study objectives, procedures, potential benefits, and possible risks. Participants were informed of their right to withdraw at any stage without consequences.
Author contributions
Conceptualization: N.S.,; Methodology: F.Gh.,; Software: H.A.,; Validation: M.Gh.,; Formal analysis: F.N.,; Investigation: N.S.; Resources: M.Gh.,; Data curation: F.Gh.,; Writing -original draft: N.S.,; Writing–review & editing: H.A.,; Visualization: F.N.,; Supervision: F.Gh.; Project administration: H.A.; Funding acquisition: N.S..
