Exercise-induced circulating microRNA changes in athletes in various training scenarios

Area of Science:

• Exercise Physiology
• Molecular Biology
• Biomarkers

Background:

• Extracellular microRNAs (miRNAs) are increasingly recognized as potential biomarkers for physiological responses to exercise.
• Understanding how different training modalities affect miRNA profiles is crucial for optimizing athletic performance and recovery.

Purpose of the Study:

• To compare the effects of 8-week explosive strength training (EXPL), hypertrophic strength training (HYP), and high-intensity interval training (HIIT) on selected extracellular miRNA levels (miR-16, miR-21, miR-93, miR-222).
• To investigate the predictive role of baseline miRNA levels on training response in young male athletes.

Main Methods:

• Thirty young male athletes were randomly assigned to EXPL, HYP, or HIIT groups for an 8-week training program.
• Blood plasma samples were collected at baseline, week 5, and week 8. Anthropometric and physical activity parameters were measured.
• Participants were classified as responders (RES) or non-responders (NRES) based on changes in strength and body composition.

Main Results:

• No significant differences in baseline miRNA levels were observed between the training groups.
• Baseline miRNA levels (miR-16, miR-21, miR-93, miR-222) did not significantly predict training response across all measured parameters using univariate regression.
• Baseline miR-93 levels showed a trend towards predicting responder status for isometric leg extension (p=0.052).

Conclusions:

• All three training regimens (EXPL, HYP, HIIT) induced significant changes in circulating miR-16, miR-21, miR-93, and miR-222 levels in young male athletes over 8 weeks.
• While baseline miRNA levels did not strongly predict overall training response, miR-93 warrants further investigation for its potential role in predicting specific strength adaptations.