Exercise-Induced Cell-Free DNA Correlates with Energy Expenditure in Multiple Exercise Protocols

Area of Science:

• Exercise physiology
• Molecular biology
• Biomarker research

Background:

• Exercise-induced cell-free DNA (ei-cfDNA) is a known response to physical activity.
• Previous studies noted correlations between ei-cfDNA, exercise intensity, and duration.
• Comprehensive data on tissue of origin and precise exercise variable links are limited.

Purpose of the Study:

• To establish precise relationships between exercise variables (intensity, duration, type) and ei-cfDNA.
• To identify the specific tissues of origin for ei-cfDNA following exercise.
• To provide further evidence for ei-cfDNA as a reliable biomarker of exercise.

Main Methods:

• A crossover study involving 12 active adults performing endurance and resistance tests.
• Blood samples collected pre- and post-exercise sessions.
• Quantification of cfDNA and determination of its tissue origin using DNA methylation patterns.

Main Results:

• ei-cfDNA fold change correlated with energy expenditure in endurance exercise (P=0.001).
• ei-cfDNA fold change correlated with years of training in resistance exercise (P=0.001).
• The primary source of ei-cfDNA was white blood cells (~95%), predominantly neutrophils (~74%), with variations between exercise types.

Conclusions:

• Exercise-induced cfDNA shows strong correlations with energy expenditure and training.
• The tissue of origin for ei-cfDNA is consistently identified, primarily white blood cells.
• Further research is warranted to explore sex differences and clinical applications of ei-cfDNA as an exercise biomarker.