Endurance exercise changes how the liver produces energy, but the process looks different in males and females, according to new research from the University of Missouri School of Medicine published in the journal Cell Reports.

The researchers found that exercise altered the Krebs cycle — the process by which liver cells create energy inside mitochondria. Female rats produced more new proteins linked to the energy cycle, while male rats modified more of their existing proteins through chemical changes.

'Male and female liver cells adapt to endurance exercise through distinct molecular pathways,' said lead author Scott Rector. He added that one sex does not necessarily have a 'better' response.

The findings add to growing evidence that biological sex shapes how the body responds to exercise, which could matter for designing personalised fitness and metabolic treatments.

The study was conducted in rats, so the results may not apply directly to humans. Readers should treat animal research as early-stage science, not medical advice.